Interim Guide to the Specifications for Hazardous Substance Thresholds under the HSNO Act

Contents

0 Preface
Introduction
2 How to use this guide
     

2.1 Mixtures
2.2 Substance Evaluation Sheet
2.3 Layout of each property threshold

3   The threshold for substances with an explosive property

3.1 General approach taken for the explosive properties
3.2 Elements of the explosive threshold
3.3 Explosive threshold technical description

3.3.1 Explosiveness threshold:
3.3.2 Sensitiveness threshold:
3.3.3 A substance designed to detonate, deflagrate, or produce a pyrotechnic effect:

3.4 Notes on explosive thresholds

3.4.1 Acceptable test results
3.4.2 Criterion of being designed to detonate, deflagrate or produce a pyrotechnic effect
3.4.3 Mixture rule for explosive substances

4 The threshold for substances with flammable properties

4.1 General approach taken for flammable properties

4.1.1 Elements of the flammable thresholds

4.2 Flammable threshold technical description

4.2.1 Flammable Gases
4.2.2 Flammable Aerosols
4.2.3 Flammable liquids
4.2.4 Flammable solids
4.2.5 Solids that may cause fire through friction
4.2.6 Self-reactive substances
4.2.7 Desensitised explosives
4.2.8 Substances liable to spontaneous combustion, pyrophoric and self heating substances
4.2.9 Substances which in contact with water emit flammable gases

4.3 Interpretation of terms used in the flammable thresholds
4.4 Notes on the flammable thresholds

4.4.1 Threshold Tests for Substances with Flammable Properties
4.4.2 Relationship to the Gas Act 1992
4.4.3 Flammable Gases

4.4.3.1 Measuring the flammability of gases

4.4.4 Flammable Aerosols
4.4.5 Flammable liquids

4.4.5.1 Measuring the flammability of liquids
4.4.5.2 Flash point limit
4.4.5.3 Viscous substances:

4.4.6 Flammable solids and related areas - Particle size
4.4.7 Flammable solids

4.4.7.1 Test Measures:

4.4.8 Solids that may cause fire though friction
4.4.9 Self-reactive substances

4.4.9.1 Test Measures

4.4.10 Desensitised explosives
4.4.11 Substances liable to spontaneous combustion, pyrophoric and self heating substances

4.4.11.1 Test Measures:

4.4.12 Substances which in contact with water emit flammable gases

4.4.12.1 Test Measures

5 The threshold for substances with oxidising properties

5.1 General approach taken for oxidising properties.
5.2 Elements of the oxidising threshold
5.3 Oxidising threshold technical description.

5.3.1 Oxidising substances not organic peroxides.
5.3.2 Organic peroxides.

5.4 Notes on the oxidising thresholds

5.4.1 Threshold Tests for Substances with Oxidising Properties
5.4.2 Organic peroxides

5.4.2.1 Threshold limits
5.4.2.2 Effects of some organic peroxides

6 The threshold for substances with corrosive properties

6.1 General approach taken
6.2 Elements of the corrosive threshold
6.3 Corrosive threshold technical description

6.3.1 Biologically corrosive
6.3.2 Metallic corrosive

6.4 Notes on the corrosive threshold:

6.4.1 Threshold Tests for Substances with Corrosive Properties

7 The threshold for substances with toxic properties

7.1 General approach taken for toxic properties.
7.2 Elements of the toxic thresholds.
7.3 Toxic threshold technical description

7.3.1 Acute toxicity
7.3.2 Skin Irritation
7.3.3 Eye Irritation
7.3.4 Sensitisation
7.3.5 Mutagenicity
7.3.6 Reproductive/Developmental/Teratogenic Effects or Chronic Toxicity
7.3.7 Any other statistically significant adverse biological effect

7.4 Notes on toxic threshold:

7.4.1 Threshold Tests for Substances with toxic properties
7.4.2 Cut-off values for acute toxicity

8 The threshold for substances with ecotoxic properties

8.1 General approach taken for ecotoxic properties.
8.2 Elements of the ecotoxic threshold.
8.3 Ecotoxic threshold technical description

8.3.1 Ecotoxic to the aquatic environment
8.3.2 Ecotoxic to the soil environment
8.3.3 Ecotoxic to terrestrial vertebrates
8.3.4 Ecotoxic to beneficial terrestrial invertebrates
8.3.5 Substances designed to cause Biocidal action

8.4 Notes on the ecotoxic threshold:

8.4.1 Threshold Tests for Substances with ecotoxic properties
8.4.2 Soil compartment and terrestrial vertebrate ecotoxicity
8.4.3 Substances designed for biocidal action

Appendix A: International Harmonisation

 

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Preface

The Hazardous Substances and New Organisms (HSNO) Act 1996 reforms and restates the law relating to the management of hazardous substances and new organisms in New Zealand. With particular reference to hazardous substances, the HSNO Act replaces the Dangerous Goods Act 1974, the Explosives Act 1957, the Pesticides Act 1979 and the Toxic Substances Act 1979 and the regulations associated with these acts. The reforms will be complete once the transitional period (presently 1 January 2001, but likely to be extended) expires.

A key feature to the management of hazardous substances under the HSNO Act is determining what substances are classed as "hazardous substances".

The initial responsibility for making this judgement rests with the importer, manufacturer or user of the substance. To assist you in making this decision ERMA New Zealand has prepared this guide. This is an interim guide. It will be published in final form when the threshold regulations are promulgated. The determination as to whether a substance is "hazardous" is not only a technical determination but also a legal one. The manufacture, importation or use of a hazardous substance without an approval is an offence. The ultimate determination of whether a substance is hazardous would be made by the courts. For example, if a company is using a hazardous substance otherwise than in accordance with a HSNO Act approval, it could be prosecuted by a HSNO enforcement agency such as Occupational Safety & Health (OSH).

Therefore, we strongly recommend that if, after completing an evaluation, you decide that your substance is not hazardous you thoroughly document your reasons. You may also wish to obtain expert advice, both scientific and legal, to support your decision. Please do not send your evaluation to ERMA New Zealand for validation. ERMA New Zealand will only make determinations in special circumstances .

However, if you conclude that your substance is hazardous you will need to come to ERMA New Zealand for an approval. If you are considering making an application to import or manufacture it, our staff will be happy to provide advice. You may obtain more information on the HSNO Act and ERMA New Zealand procedures from our website (www.ermanz.govt.nz).

 

 

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1 INTRODUCTION

This technical guide provides a framework to determine whether a substance is hazardous and is subject to the requirements of the Hazardous Substances and New Organisms Act 1996 (HSNO Act). This is an interim version of the guide, prepared using the policy material developed by the Ministry for the Environment (MfE). When this policy material has been drafted into hazardous property regulations and passed into law by the government, we will revise this guide to reflect the actual content of the final regulations.

Hazardous substances occur in many parts of our daily lives. They include a wide range of materials such as petrol, pesticides, bleaches, some paints, dishwashing powders, various industrial solvents, fireworks, medicines, flea powders, dynamite, liquefied petroleum gas (LPG), and many more. The HSNO Act has a very broad definition of "substance". It may be a pure chemical element or compound, it may be a mixture of compounds (often called a product) or it may be a mixture of compounds with the components specified in defined ranges (e.g. a product range). When you are considering how to define your substance you will need to consider these aspects and define it in accordance with the HSNO Act.

A substance is considered to be a "hazardous substance" when it has a property more hazardous than any one or more of the thresholds for any of the following intrinsic properties:

  • Explosiveness
  • Flammability
  • Oxidising capacity
  • Corrosiveness
  • Toxicity
  • Eco-toxicity

The MfE has developed these thresholds on the basis of internationally recognised standards and knowledge. The thresholds reflect the international trend to harmonisation, see Appendix A of this guide.

The initial responsibility for making a judgement as to whether a substance is hazardous rests with the importer, manufacturer or user of the substance. You are required to assess each substance that you wish to import, or manufacture in New Zealand, for each of the above properties. The hazardous property threshold regulations, set under section 74 (b) of the HSNO Act, set the level of hazard below which any substance is not considered hazardous. This guide aims to assist you to interpret the threshold regulations, apply them to your substance and help you to decide whether or not your substance is hazardous.

If it is not a hazardous substance, the provisions of the HSNO Act do not apply. If it is hazardous, you will need an approval from ERMA New Zealand to import, manufacture or use it.

We recommend that if, after completing an evaluation, you decide that your substance is not hazardous you thoroughly document your reasons. You may also wish to obtain expert advice, both scientific and legal, to support your decision.

The HSNO Act states that "No hazardous substance shall be imported or manufactured otherwise than in accordance with an approval issued under this Act or in accordance with Parts XI to XVI of this Act". These latter Parts refer to the transitional provisions for existing pesticides, toxic substances, dangerous goods and explosives.

If your substance is hazardous it will need to come under the control of the HSNO Act (whether via the transitional process or through a Part V application for a new substance ). When a substance is considered hazardous it will be classified, after evaluation of the risks posed by the substance and, if approved, the appropriate controls assigned either by the Authority or as part of the transfer process.

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2 How to use this guide

The guide has separate sections for each hazardous property. While many substances will be only more hazardous than one threshold, many other substances will also trigger more than one property. Therefore it is necessary to evaluate each substance against the thresholds in each section. This evaluation is a moderately complex technical task.

We have developed this guide on the presumption that you have sufficient scientific and technical knowledge and experience to determine whether a substance is hazardous or not. It requires you to address each hazardous property individually and to address the specific criteria within each property that may trigger the threshold. If you do not have the ability to address the technical issues, you should seek advice from people who do. You may also need to seek legal advice as well.

To evaluate a substance you should collect as much relevant information about the characteristics of the substance as you reasonably can. You should then compare this information with the criteria in each property threshold. An inability to access the information does not necessarily mean there is no such information. If you do not have adequate information you will have to use technical judgement, including:

  • Do similar substances have properties that would give reliable guidance?
  • Is it plainly unreasonable to expect the substance to have such a property?
  • Should this gap be referred to an expert in the field?

If a substance is not more hazardous than any of the thresholds, it is not "hazardous" and does not need an approval from the Authority. However if a substance does trigger the threshold level, then it cannot be imported or manufactured in New Zealand other than in accordance with an approval from the Authority. If your substance is hazardous, you will need to make an application prior to importing or manufacturing it. Further information about the application process can be obtained from ERMA New Zealand.

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2.1 Mixtures

As mentioned in the Introduction, the definition of substance includes mixtures. This section explains how the hazardous property thresholds can be applied to substances that are multi-component chemical products, when there is a lack of test data available on the substance.

When test data are available on a mixture (e.g. a product or preparation), then these data will be used to evaluate and classify the product as if it were a single chemical substance.

The term "mixture" is used for substances that are combinations of two or more single chemical entities, which have not reacted to form other chemical entities at the time of classification. By "single chemical entity" we mean any material that has been identified separately for hazard classification purposes. For example, certain petroleum streams are identified as if they are a single substance, but in fact are mixtures of separately identifiable chemicals that have similar properties such as boiling point. Nevertheless, these mixtures are traded in commerce as single chemical products, are evaluated as a single chemical entities, and are identified by the Chemical Abstracts Service as single chemical entities and we regard then as a single substance.

Recognising that most mixtures have not been tested as a whole for health hazards, there are several international systems that permit the evaluation of the hazards of mixtures from the properties and concentrations of the components. These systems are referred to as "mixture rules." Calculation rules for combining information about the components of the mixture and/or estimation techniques will be accepted as a means of establishing whether or not a given substance triggers the threshold. Comments on how to deal with mixtures are given, where appropriate, in each section of this guide.

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2.2 Substance Evaluation Sheet

We have provided a "Substance Evaluation Sheet" to guide you through the process of assessing whether a substance is hazardous under the HSNO Act. The sheet helps you to consider if you have the necessary information and leads you through an assessment of the substance for each hazardous property. It has been designed so that one sheet is used for each substance. You may either copy the sheet, or obtain further copies from ERMA New Zealand, or download it from the website (www.ermanz.govt.nz). By working through the evaluation sheet in conjunction with this guide, you should be able to decide whether your substance should be classed as being a hazardous substance. The guide and evaluation sheet are for your own use. Please do not send your evaluation to ERMA New Zealand for validation.

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2.3 Layout of each property threshold

Each of the following sections includes:

  • an introduction
  • the property thresholds
  • an explanatory note
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3 The threshold for substances with an eplosive property

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3.1 General approach taken for the explosive properties

This threshold is derived from the United Nations Recommendations on the Transport of Dangerous Goods (UNRTDG) Model Regulations, 10th Revised Edition, 1997, and its companion volume, UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995.

These are available from the United Nations via their website and are also available in New Zealand (on order) from government bookshops.

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3.2 Elements of the explosive threshold

There are 3 elements of the threshold for substances with an explosive property:

  1. explosiveness
  2. sensitiveness to stimuli (likelihood of detonating or deflagrating)
  3. a substance or substances designed to detonate, deflagrate or produce a pyrotechnic effect.
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3.3 Explosive threshold technical description

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3.3.1 Explosiveness threshold:

A substance is above the explosive threshold if it would give a positive result to either of the tests type (a) and (c) in UN Test Series 1 of UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995 (p 27-46), as follows:

In a Type (a) or the UN gap test, when confined in the prescribed steel tube and subjected to detonation by the prescribed booster charge, the substance is able to propagate a detonation, shown by fragmenting the tube completely or punching a hole through the prescribed witness plate.

In a Type (c) time/pressure test of the effect of ignition, when confined in the prescribed steel pressure vessel and ignited by the prescribed electric fusehead, the substance is able to demonstrate a pressure rise from 690 kPa to 2070 kPa or more.

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3.3.2 Sensitiveness threshold:

A substance is above the sensitiveness threshold if it would give a positive result to any of the three types of tests in UN Test Series 2 of UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995 (p 47-66) as follows: (Differences from Test Series 1 are underlined for ease of identification)

In a Type (a) or UN gap test, when confined in the prescribed steel tube and subjected to detonative shock by initiating the prescribed booster charge, which is separated from the test substance by the prescribed spacer, the substance is able to propagate a detonation as shown by fragmenting the tube completely or punching a hole through the prescribed witness plate.

In a Type (b) or Koenen test, when confined in the prescribed steel tube with a closing plate orifice of 2.0 mm or more and subjected to intense heat as prescribed, the substance is able to produce an explosion as shown by the tube being:

  • fragmented into three of more large pieces (which can still be connected by a narrow strip)
  • fragmented into many mainly small pieces, or
  • fragmented into many very small pieces and the closing device bulged out or fragmented.

In a Type (c) time/pressure test of the effect of ignition, when confined in the prescribed steel pressure vessel and ignited by the prescribed electric fusehead, the substance is able to demonstrate a pressure rise from 690 kPa to 2070 kPa or more, within 30 ms.

Definition: Sensitiveness measures the response of an explosive substance to some accidental stimuli.

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3.3.3 A substance designed to detonate, deflagrate, or produce a pyrotechnic effect:

A substance designed to detonate will, when initiated, produce a violent chemical reaction that proceeds through the reacted material at supersonic velocity producing heat and high pressure. The result of the reaction is exertion of extremely high pressures on the surrounding medium forming a propagating shock wave of supersonic velocity.

A substance designed to deflagrate will, when initiated, produce a chemical reaction which proceeds at subsonic velocity along the surface of, and/or through the reacted material producing hot gases at high pressures. A deflagration under confinement increases pressure, the rate of reaction and the temperature, which may cause detonation.

A substance designed to produce a pyrotechnic effect will, when initiated, produce a non-detonative, self-sustaining exothermic chemical reaction producing an effect of heat, light, sound, delay, smoke, gas or motion or a combination of these.

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3.4 Notes on explosive thresholds:


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3.4.1 Acceptable test results

Apart from the criterion of being designed to detonate, deflagrate, or produce a pyrotechnic effect, this threshold specifies the UN Tests as the measure for the threshold of explosiveness. No other tests appear to be in common international usage. Accordingly, the first two sections of the threshold require test results from the UN These thresholds require the test procedures as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995. As these methods require relatively sophisticated testing facilities, it is expected that overseas test data will be the basis for assessing applications.

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3.4.2 Criterion of being designed to detonate, deflagrate or produce a pyrotechnic effect

This criterion carries over the current scope of the Explosives Act. For example, the criterion covers airbag igniters and model rockets, which are designed to deflagrate, and caps, which are designed to produce sound by a pyrotechnic effect.

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3.4.3 Mixture rule for explosive substances

There generally are no mixture rules that apply to explosive hazards. In general, the direct testing of mixtures for explosive hazards is required since the hazards of a mixture are not always reliably predictable from component data.

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4 The threshold for substances with flammable properties

4.1 General approach taken for flammable properties

The threshold criteria for flammable hazards are largely derived from the UNRTDG Model Regulations, 10th Revised Edition, 1997, and its companion volume, UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995.

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4.1.1 Elements of the flammable thresholds

There are 9 elements of the threshold for substances with a flammable property:

  • Flammable Gases
  • Flammable Aerosols
  • Flammable liquids
  • Flammable solids
  • Solids which may cause fire through friction
  • Self-reactive substances
  • Desensitised explosives
  • Substances liable to spontaneous combustion, pyrophoric and self heating substances
  • Substances which in contact with water emit flammable gases
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4.2 Flammable threshold technical description

4.2.1 Flammable Gases

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A substance is a flammable gas if it is either:

(i) a gas (including a gas mixture) which at 20°C and at a pressure of 101.3 kPa is:

(a) ignitable when in a mixture of £ 13 percent by volume with air; or
(b) is a flammable range with air of at least 12 percentage points, regardless of the lower flammability limit;

or

(ii) a gas (including a gas mixture), other than as described in (i) above, that at 20°C and a pressure of 101.3 kPa has a flammable range in mixture in air.

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Example:

Liquefied petroleum gas has, at standard temperature and pressure, a lower combustible level in air of 2% and an upper combustible level in air of 9%. Therefore it is a flammable gas according to i(a) above.


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4.2.2 Flammable Aerosols

An aerosol is a flammable aerosol if it is a pressurised mixture containing a gas, compressed, liquefied, or dissolved under pressure, with or without a liquid, paste or powder; comprising at least 45% by mass of flammable ingredients; under a pressure greater than 100 kPa.

In this context, "flammable ingredient" means any substance which meets the threshold for either a "flammable gas," "flammable liquid," or "flammable solid"; or any combination of these.



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4.2.3 Flammable liquids

A liquid is a flammable liquid if it:

(a) gives off a flammable vapour which ignites in a closed cup flash point test at a temperature £ 93°C;
(b) is intended to be manufactured, stored, transported or used (except deliberately burnt) at a temperature at or above its flash point.

Example:

Xylene has a flash point of 28°C and therefore is a flammable liquid; ethylene glycol has a flash point of 111°C and would NOT be a flammable liquid unless it was used above its flash point (as is quite likely) according to threshold (b) above.


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4.2.4 Flammable solids

A solid is a flammable solid if it meets the criteria for the burning rate test set out in subsection 33.2.1 UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995.

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4.2.5 Solids that may cause fire through friction

Substances with the following UN numbers are flammable solids:

  • 1331 Matches, "strike anywhere"
  • 2254 Matches, fusee
  • 1944 Matches, safety (book, card and strike-on-a-box)
  • 1945 Matches, wax "vesta"
  • 1343 Phosphorus trisulphide
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4.2.6 Self-reactive substances

A substance is a flammable self-reactive substance if either:

(i) a 50 kg quantity of the substance, (when contained as specified in any of the tests set out in section 28 (p283-304) UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995), has a self-acceleration decomposition temperature (SADT) < 75°C, when tested in accordance with such tests; and
(ii) it has a heat of decomposition greater than 300 J/g, determined using differential scanning calorimetry, or adiabatic calorimetry.
or

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The substance is listed in the UNRTDG Model Regulations [10th Edition 1997] as having a classification, division or subsidiary risk of a self-reactive substance [Division 4.1(b)].

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4.2.7 Desensitised explosives

A substance is a flammable desensitised explosive substance if

(i) prior to being desensitised, it would meet the threshold for substances with explosive properties

and

(ii) it has been desensitised to the extent that it would, under Test Series 6c of the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995 show no projection, fire, smoke, heat or noise effect external to the substance itself;

and

(iii) it neither meets the criteria for substances with oxidising properties, nor for self-reactive substances (i.e. is not also in another hazardous category)
or

the substance is listed in the UNRTDG Model Regulations [10th Edition 1997] as having a classification, division or subsidiary risk of a desensitised explosive [Division 4.1(c)];

or

the substance is one of the following substances (UN number):

  • 5-tert-Butyl-2,4,6-trinitro-m-xylene (musk xylene) (UN 2956),
  • 2-Bromo-2-nitropropane-1,2-diol (UN 3241),
  • Azodicarbonamide (UN 3242), and
  • Iso-Sorbide-5-mononitrate (UN 3251).
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4.2.8 Substances liable to spontaneous combustion, pyrophoric and self heating substances

A substance is a flammable substance if, when tested as described in section 33.3.1 UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995, it meets one or more of the following criteria:

(i) if the substance is a solid in powder form and in its commercial form ignites while falling or within 5 minutes of settling when poured from about 1 metre height onto a non-combustible surface, in one or more times out of six.

(ii) if the substance is a liquid, and if 5 ml of the liquid:
when poured into an inert container containing an inert solid powder, ignites when exposed to air for five minutes, in one or more times out of six; or
when added to a dry filter paper at 25°C, ignition or charring occurs on the filter paper within five minutes of addition of the liquid, in one or more times out of three.

(iii) if a solid cube of the substance with sides 100mm long, when heated to 140°C, either spontaneously ignites or experiences a 60°C rise in temperature during a 24 hour period.

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4.2.9 Substances which in contact with water emit flammable gases

A substance is a flammable substance if, when tested as described in subsection 33.4.1 UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995, it meets one or both of the following criteria:
(a) at ambient temperatures, reacts with water and produces a gas which ignites spontaneously; or
(b) when in contact with water produces flammable gas at a rate ³ 1 litre/kg/hr.

Note:
For sections 5.2.4 - 5.2.9 of this threshold, where the substance is known to be likely to crumble into a finer particle form, or to be used in a finer particle form than the form in which it is initially presented, then the test should be conducted using that finer form.

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4.3 Interpretation of terms used in the flammable thresholds

Flammability the ability of a substance to be ignited and to support combustion in air at 20°C, 101.3 kPa absolute pressure.

Flammable able to be ignited and sustain combustion, in air at 20°C, 101.3 kPa absolute pressure.

Flammable range the range between the points where the ratio of flammable substances to air is either too low ("too lean"), or too high ("too rich") to be able to support combustion. The term "flammable range" includes a minimal range effectively equivalent to a single point.

Flammable vapour the gaseous form of a normally liquid or solid substance, that is flammable.

Flash point The lowest temperature at which a liquid gives off sufficient vapour to form a flammable mixture with air, in any closed cup flash point test (e.g. carried out in accordance with ISO 2592).

Gas a substance that is completely in the gaseous state at normal temperature and pressure 20°C and 101.3 kPa; or a substance with a vapour pressure at 50°C > 300 kPa

Ignitable able to be set on fire.
Liquid As defined in the 10th Revised Edition of the UNRTDG (chapter 1.2). (Refer to the document for a full definition but essentially:

  • Substances with a melting point £ 20°C at 300 kPa; or
  • (for viscous substances without a defined melting point), tested according to ASTM

D 4359-90 or the other tests detailed in this section)
Liquids may contain solids in solution or suspension.

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4.4 Notes on the flammable thresholds:

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4.4.1 Threshold Tests for Substances with Flammable Properties

The approach taken to defining tests and criteria for thresholds for flammable substances is as follows:

a) In some cases, because of the sensitivity and degree of hazard of the substance, and for the sake of consistency in results, the criteria are dependent on precise testing procedures being followed. In these cases, the regulation will specify the specific testing procedures required, in one of two ways:

(i) a narrative description of the test method (this allows equivalent tests to be performed); or
(ii) the reference to a particular test is specified in the regulations, in which case only that test will be able to be accepted.

b) In cases where the criteria have a well- defined and universally understood meaning by themselves (e.g. "closed cup flash point test", for which the UNRTDG lists 19 recognised tests), the regulation will be limited to specifying the criteria, enabling any appropriate test to be used. This approach also permits calculation or estimation methods to be considered - e.g. for mixtures.

It is anticipated that ERMA New Zealand will provide guidance in the final version of this guide as to what test protocols or methods would be recognised as acceptable tests for the specified threshold criteria. It is expected that whatever protocols or methods ERMA New Zealand chooses, the test protocols or test methods specified in:

  • the UNRTDG Model Regulations, 10th Revised Edition, 1997; or
  • the UNRTDG Manual of Tests and Criteria. 2nd Revised Edition, 1995
    will be acceptable.
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4.4.2 Relationship to the Gas Act 1992

The HSNO Regulations are not intended to apply to any gas distribution and transmission system, which comes under the provisions of the Gas Act 1992. While substances such as gas are clearly flammable, the Gas Act generally provides up to date and effective control in these circumstances. Consequently, MfE proposes that specific provisions will be included in the HSNO regulations to avoid any overlap of regulation with the Gas Act controls. For example, section 75(1)(g) HSNO Act could be used to exclude fuel gases contained in gas distribution and transmission system as defined in the Gas Act 1992. This follows the existing practice as defined in the Dangerous Goods (Class 2 - Gases) Regulations: "Nothing in these Regulations shall apply to (a) coal gas or natural gas except when packed, stored, conveyed or handled in cylinders or transportable tanks".

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4.4.3 Flammable Gases

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4.4.3.1 Measuring the flammability of gases

UNRTDG Model Regulations, 10th Revised Edition, 1997 (s. 2.2.2) recommend that "flammability should be determined in accordance with ISO 10156:1996). Where insufficient data are available to use these methods, tests by a comparable method recognised by a national competent authority may be used."

The ISO 10156:1996 test involves introducing a known concentration of gas: air mixture, in a reaction tube fitted with an ignition spark plug with 5 mm gap, connected to a 15 kV spark generator, and observing whether a spark results in a flame rising up the tube. The procedure involves beginning with a low concentration of gas, and repeating the test a number of times, each time gradually increasing the concentration of gas until a spark results in a flame rising up the tube. The calculation methods in the ISO standard appear to only apply to certain applications such as special gas mixtures produced to order (in small quantities).

Alternative test methods include:

  • Coward, HF and Jones, GW, "Limits of Flammability of Gases and Vapours", US Bureau of Mines Bulletin 503. (For calculating limits of flammability of gas mixtures).

  • Zabetakis, M G "Flammability Characteristics of Combustible Gases and Vapours". US Bureau of Mines Bulletin 627, 1965.

  • Burgess, D S, Furno, A L, Kutch, J M, and Mura, K E Flammability of Mixed Gases. Us Department of the Interior, Bureau of Mines Report of Investigations 8709, 1982.

  • BS 5345 Part 1: 1989 British Standard Code of Practice for Selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres (other than in mining applications or explosives processing and manufacture). Part 1 General Recommendations.

  • ASTM Standard E918 - 83 (1988). Determining Limits of Flammability of Chemicals at Elevated Temperature and Pressure.
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4.4.4 Flammable Aerosols

The UNRTDG definition of "aerosols" (chapter 3: notes 63 & 190) combines a description of the substance, and a description of the package, as follows:

63: if the contents include more than 45 percent by mass or more than 250 g, of flammable components*

* UNRTDG defines flammable components in aerosols as "gases that are flammable in air at normal pressure, or are substances or preparations that are in liquid form that have a flash point £ 100 °C".

190: Aerosols (as amended by ST/SG/AC.10/c.3/28/Add.3), this means aerosol dispensers, are any non-refillable receptacles made of metal, glass or plastic and containing a gas compressed, liquefied, or dissolved under pressure, with or without a liquid, paste or powder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder, or in a liquid state, or in a gaseous state.

The definitions of aerosol in European Community Directive 75/324/EEC, and the ICAO Technical Instructions are virtually identical to the UNRTDG definition. The EC Directive sets a maximum capacity of metal aerosol dispensers of 1000 ml. A recent amendment to the EC legislation apparently requires all aerosols with any flammable contents to be considered as flammable unless tests indicate that it is not.

The approach used to specifying the threshold is required because the regulation making powers in the HSNO Act differentiate between the substance and the controls applied to it. When the above specification of aerosol is combined with the controls on flammable aerosols and the requirements for packages, the end result will be equivalent to the approach taken by the UN, EC, and ICAO.

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4.4.5 Flammable liquids

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4.4.5.1 Measuring the flammability of liquids

The relevant recommended test methods and criteria specified in section 2.3 UNRTDG are closed cup flash point tests. Because section 2.3.3 UNRTDG lists 19 accepted tests (and there may be others), the proposal does not specify a particular means.


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4.4.5.2 Flash point limit

The proposal that the threshold include liquids with a flash point £ 93°C originates from an August 1996 proposal of the UNCETDG Subcommittee advising the IOMC Co-ordinating Group on flammability to modify the UNRTDG criteria to make it applicable to other aspects of the lifecycle. The Subcommittee has confirmed this proposal.

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4.4.5.3 Viscous substances:

UNRTDG exempts some specific types of viscous flammable substances from land transport controls, but the exemption does not apply for sea and air transport. Refer to sections 5.3.5, 5.5 and 5.6 in the UNRTDG.

Accordingly, no exemptions are provided by reason of viscosity although, as with other hazards, a substance above the threshold is captured for assessment rather than automatically having controls imposed.

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4.4.6 Flammable solids and related areas - Particle size

The ILO/UN Working Group has considered the question of particle size for testing of flammable solids and concluded (ST/SG/AC.10/C.3/Add.3):

  • that tests for solids should be carried out on substances in the form as presented [e.g. for transport];
  • if the substance was to be presented [for use] in a different form which might alter its behaviour on testing, it should be re-tested in its different form; and
  • if it was reasonably foreseeable that a substance would considerably change its material form during its lifetime, the potential hazards of its changed form should also be taken into consideration.
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4.4.7 Flammable solids

The threshold proposed is equivalent to that for Division 4.1(a) as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995.

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4.4.7.1 Test Measures:

The apparatus and procedure for the Burning Rate test are set out in s.33.2.1.4 Tests & Criteria. If the substance fails the Preliminary screening test (33.2.1 Tests & Criteria), the substance may be considered not to be a flammable solid, and no further testing need be carried out. If the substance passes the Preliminary screening test, the Burning Rate test should be carried out. We are not aware of any alternative comparable method recognised by any national competent authority.

This particular test has been specified in regulation, and information used in the evaluation must have been obtained using this test. This is because the rate of propagation of the flame is dependent upon how the test is conducted, e.g. the cross sectional area of the powder trail, and on how compacted the powder is in the trail.

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4.4.8 Solids that may cause fire though friction

As indicated there are only a small number of individual 'substances' which may cause fire through friction listed in the UNRTDG, accordingly this part of the threshold has been included simply by listing these substances.

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4.4.9 Self-reactive substances

The threshold proposed is equivalent to that for Division 4.1(b) (including Type G) as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995.

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4.4.9.1 Test Measures

The degree to which these substances will heat up internally depends on

  • the surface to volume ratio of the quantity of substance presented; and
  • the nature (e.g. the thermal conductivity) of the container or package it is in.

Accordingly, the test procedures described in UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995 are directly referred to for this threshold.

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4.4.10 Desensitised explosives

The threshold proposed is equivalent to that for Division 4.1(c) as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995 but also includes (as a result of the work of the IOMC sub-committee of the UNCETDG) substances related to self-reactive substances.



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4.4.11 Substances liable to spontaneous combustion, pyrophoric and self heating substances

The threshold proposed is equivalent to that for Division 4.2 as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995.



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4.4.11.1 Test Measures:

  • Pyrophoric solids: the test is set out in section 33.3.1.4 Tests & Criteria;
  • Pyrophoric liquids: the test is set out in section 33.3.1.5 Tests & Criteria;
  • Self-heating solids: the test is set out in section 33.3.1.6 Tests & Criteria, including the specifications for the test apparatus - the hot-air circulating oven, cubic sample containers, covers, and cages; and thermocouple.

As we are not aware of any alternative comparable test methods recognised by any national competent authority other than those described above these tests have been used to define the threshold.

 

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4.4.12 Substances which in contact with water emit flammable gases

The threshold proposed is equivalent to that for Division 4.3 as set out in the UNRTDG Manual of Tests and Criteria, 2nd revised edition 1995.

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4.4.12.1 Test Measures:

Details of the test method for substances which in contact with water emit flammable gases, are detailed in subsection 33.4.1 Tests & Criteria. Again, there appear to be no alternative comparable method recognised by any national competent authority so the tests have been used to define the threshold.

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5 The threshold for substances with oxidising properties

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5.1 General approach taken for oxidising properties.

The oxidising threshold criteria are derived from the UNRTDG Model Regulations, 10th Revised Edition, 1997, and its companion volume, UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995.

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5.2 Elements of the oxidising threshold

There are 2 elements of the threshold for substances with an oxidising property:

  • oxidising substances not organic peroxides, being substances which while in themselves not necessarily combustible may, generally by yielding oxygen, chlorine or fluorine, cause or contribute to the combustion of other material
  • organic peroxides, being substances which contain the bivalent oxygen [-0-0-] structure and may be considered as derivatives of hydrogen peroxide where one or both of the hydrogen atoms has been replaced by an organic radical
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5.3 Oxidising threshold technical description.

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5.3.1 Oxidising substances not organic peroxides.

A substance is an oxidising substance if either:

a) The substance is listed in the UNRTDG Model Regulations, 10th Revised Edition, 1997, as having a classification, division or subsidiary risk of an oxidising substance [Classification Division 5.1];

or

b) For a solid, if when tested in the form in which it is generally available by mixing with dried cellulose it is found the mixture shows a mean burn time equal to or faster than that of the reference mixture of potassium bromate and cellulose described in the test, except that the physical form of the substance presented for testing should also be considered. Where the substance is known to be likely to crumble into a finer particle form by more than 10% of its mass, or it is likely to be used in a finer particle form, then the substance should be prepared and tested using that finer form;

or

c) for a liquid, if when tested by mixing with dried cellulose it is found the mixture shows a mean pressure rise time that is equal to or faster than the mean pressure rise time of the reference mixture of 65% aqueous nitric acid and cellulose described in the test ;

or

d) for a gas, when tested the substance will cause or contribute to combustion at a faster rate than air does;


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5.3.2 Organic peroxides.

An organic peroxide is an oxidising substance if any of the following conditions apply:

either

a) The substance is listed in the UNRTDG Model Regulations, 10th Revised Edition, 1997, as having a classification, division or subsidiary risk of an organic peroxide [Classification Division 5.2];

or

b) the substances provides more than 1% available oxygen from the organic peroxides, when containing less than 1% hydrogen peroxide;

or

c) the substance provides more than 0.5% available oxygen from the organic peroxides, when containing between 1% and up to 7% hydrogen peroxide;

If the substance is a mixture and any of the constituent chemical elements or compounds in the mixture meet any of the criteria in (1) or (2) above, unless the mixture [i.e. as it is imported or manufactured] does not itself meet the criteria set out in (1) (b), or (c) or (d) or (2) (b) or (c) above.

Definitions

Available oxygen content:

For an organic peroxide, the available oxygen content as a percent (%) is determined according to the following formula:
Where:
ni = number of peroxygen groups per molecule of organic peroxide i
ci = concentration [mass %] of organic peroxide i
mi = molecular mass of organic peroxide i
x = multiplication symbol
å = symbol for summation

This formula calculates the availability of oxygen as a percent by mass. The "i" is a mathematical expression to allow for adding up the available oxygen for each component in a mixture. Mixtures of different organic peroxides with or without hydrogen peroxide are common.

Gas means:

A substance that has a vapour pressure greater than 300 kilopascals [ kPa ] at 50 degrees Celsius [ ºC]

or

A substance that is completely gaseous at 20 ºC and a standard pressure of 101.3 kPa


Tested means tested according to the methods set out as follows:

For testing oxidising solids or liquids:

The UNRTDG Model Regulations, 10th Revised Edition, 1997 and in the UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995; except that for a solid, where the substance is known to be likely to crumble into a finer particle form, or to be used in a finer particle form than the form as transported, then the test should be conducted using that finer form.

For testing a gas:

Those parts of ISO 10156 :1996 that relate to determining the oxidising potential of a gas.

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5.4 Notes on the oxidising thresholds:

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5.4.1 Threshold Tests for Substances with Oxidising Properties

The approach taken to defining tests and criteria for thresholds for oxidising substances is to specify the specific testing procedures based on those in UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995, and to provide that substances listed in the UNRTDG Model Regulations, 10th Revised Edition, 1997, be included. The latter is to minimise any possible need for re-testing of substances already accepted as having an oxidising property. This approach has been taken on the basis of received during the development of the regulations and because there appear to be no other recognised procedures in common usage. Similarly for gases the criterion used is a single test procedure laid out in ISO 10156 :1996.

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5.4.2 Organic peroxides

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5.4.2.1 Threshold limits

The oxidising property of a substance is not above the threshold if, for an organic peroxide, its formulation contains:

  • no more than 1.0% available oxygen from the organic peroxides when there is no more than 1.0% hydrogen peroxide; or
  • no more than 0.5% available oxygen from the organic peroxides when there is more than 1.0% but not more than 7.0% hydrogen peroxide.

There has been some international debate as to whether the cut-off should be 5% instead of 7%. The 5% value is used by the EC and could be regarded as a more sensitive threshold for potential hazards outside of transport. However, more recently the subcommittee of the UNCETDG considering this matter has agreed on the 7% criterion and so this is used as a cut off value for this threshold.



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5.4.2.2 Effects of some organic peroxides

Some organic peroxide formulations,

  • may under increased temperature evolve oxygen and thus depress the temperature at which other flammable materials may ignite;

  • can form peroxides when left to 'stand" that are unstable, and may be explosive exposure to light/air e.g. diethyl ether.

We expect consideration of the stability of a substance will consider information on such hazards.

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6 The threshold for substances with corrosive properties

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6.1 General approach taken

Within this threshold the limits for metallic corrosives are derived from the UNRTDG Model Regulations, 10th Revised Edition, 1997, and its companion volume, UNRTDG Manual of Tests and Criteria, 2nd Revised Edition, 1995. The limits for substances corrosive or irritating to tissue (biologically corrosive) are referenced to those which form part of the overall toxic threshold. The values for biologically corrosive substances are derived from the documents of the AG-HCL.

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6.2 Elements of the corrosive threshold

There are 2 elements of the threshold for substances with a corrosive property:

  • biologically corrosive substances
  • corrosive to metals
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6.3 Corrosive threshold technical description

A substance is above the threshold for a corrosive property if the conditions described in (1) and (2) below are met.

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6.3.1 Biologically corrosive

A substance is above the threshold as a biological corrosive if the criteria for skin irritation or eye irritation as listed in section 7.3.2 below are met.

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6.3.2 Metallic corrosive

A substance is above the threshold for the corrosive property if it corrodes specified steel or aluminium surfaces at a rate exceeding 6.25 mm a year at a test temperature of 55ºC.


Exclusion: Corrosion of non-metallic materials

A substance that exerts a corrosive action only on non-metallic materials and does not meet either of the criteria in (6.3.1) or (6.3.2) above is not above the threshold for corrosive properties.

Interpretations

Specified steel: Steel type P235 (ISO 9328 (II) : 1991), SAE 1020 steel.

Specified aluminium: aluminium, non-clad types 7075-T6 or AZ5GU-T6

 

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6.4 Notes on the corrosive threshold:

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6.4.1 Threshold Tests for Substances with Corrosive Properties

These specifications are limited to criteria which permit the use of any test results or estimating methods within any guidelines provided by ERMA New Zealand to establish whether a given substance is captured by the threshold.

It is anticipated that ERMA New Zealand will provide guidance in the final version of this guide as to what test protocols or methods would be recognised as acceptable tests for the specified threshold criteria. It is expected that whatever protocols or methods ERMA New Zealand chooses, the following test guidelines would met these measures:

  • United States National Association of Corrosion Engineers (NACE) Standard TM-01-69 (ref. 49CFR 173.240)

  • American Society for Testing and Materials (ASTM) standard G-31-72 (extended in 1990)

However, particularly for mixtures, it is expected that calculation rules for combining information about the components of the mixture and/or estimation techniques will be accepted as a means of establishing whether or not a substance falls above or below the threshold.

It should also be noted that older studies/methods may still provide useful information for the above measure but may pre-date currently accepted Good Laboratory Practice (GLP). It is not envisaged that information derived from these studies would be excluded from consideration.

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7 The threshold for substances with toxic properties

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7.1 General approach taken for toxic properties.

The toxic threshold criteria are derived from the documents of the Advisory Group on Harmonisation of Classification and Labelling (AG-HCL), a subcommittee of the Chemicals Group in the Organisation of Economic Co-operation and Development (OECD) Environment Directorate. These documents form part of the overall international harmonisation exercise detailed in Appendix A.

 

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7.2 Elements of the toxic thresholds.

There are 6 elements of the threshold for substances with a toxic property:

  1. Acute toxicity including oral, dermal, and inhalation effects
  2. Skin irritation (including corrosive effects)
  3. Eye irritation
  4. Sensitisation
  5. Reproductive/Developmental/Teratogenic Effects or Chronic Toxicity
  6. Other statistically significant biological effects
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7.3 Toxic threshold technical description

A substance is above the threshold for toxic effects if it is above any one of the following threshold levels



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7.3.1 Acute toxicity

(i) oral or dermal effects LD50 is £ 5000 mg substance/kg bodyweight

UNLESS

At or below the respective threshold value, reliable data becomes available from human or animal studies, which indicate no statistically significant acute toxic effect.

(ii) inhalation effects (gases) LC50 is £ 5000 ppm in air

(iii) inhalation effects (vapours) LC50 is £ 20 mg substance/l air

(iv) inhalation effects (dusts and mists) LC50 is £ 5 mg substance/l air

Example:
Benzene has a rat oral LD50 of 930 mg/kg. It is more toxic than the threshold. Note that any mixture containing more than 18.5% benzene will also be more toxic than the acute toxicity threshold. Benzene also triggers the mutgenicity threshold (at any level). In addition benzene (grass shrimp LC50 of 27 mg/l and flashpoint -11°C) is also an ecotoxic substance and a flammable liquid.

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7.3.2 Skin Irritation

(i) the pH of the substance is < 2 or > 11.5.

or

(ii) the substance exhibits a Draize Grade ³ 1.5 for either erythema or oedema.

Example:
Nitric acid in solution (0.1M) has a pH of 1 and is both a skin irritant (7.3.2) and an eye irritant (7.3.3).

 

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7.3.3 Eye Irritation

(i) the pH of the substance is < 2 or > 11.5.

or

(ii) the substance exhibits a Draize Grade ³ 1 for either corneal opacity or iritis or Draize Grade ³ 2 for either conjunctival redness or chemosis

 

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7.3.4 Sensitisation

Any positive reaction on challenge.

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7.3.5 Mutagenicity

Any positive reaction in in vivo or in vitro assays.

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7.3.6 Reproductive/Developmental/Teratogenic Effects or Chronic Toxicity

Any statistically significant adverse biological effect.

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7.3.7 Any other statistically significant adverse biological effect

Any other statistically significant adverse biological effect.

Interpretation of terms

Statistically significant adverse biological effect: a dose-response effect above a recognised background history. Statistical significance is where P £ 0.05.

Gases: is completely gaseous at 20oC at a standard pressure of 101.3 kPa.
Vapours: at 50oC has a vapour pressure greater than 300 kPa.
Dusts and Mists: the test atmosphere contains greater than 90% particles with an aerodynamic diameter of < 10 microns.
LD50 (median lethal dose): a statistically derived single dose of a substance that can be expected to cause death in 50 per cent of animals when administered by the oral or dermal route.
LC50 (median lethal concentration): a statistically derived concentration of a substance that can be expected to cause death during exposure or within a fixed time after exposure in 50 per cent of animals exposed for a specified time.

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7.4 Notes on toxic threshold:

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7.4.1 Threshold Tests for Substances with toxic properties

These specifications are limited to those which will permit the use of any test results or estimating methods (within any guidelines provided by ERMA New Zealand) to establish whether a given substance is captured by the threshold.

It is anticipated that ERMA New Zealand will provide guidance in the final version of this guide on which test protocols or methods would be recognised as acceptable tests for the specified threshold criteria. It is expected that whatever protocols and methods ERMA New Zealand chooses, the following test guidelines would meet these measures:

  • OECD Test Guidelines
  • US EPA Guidelines
  • EC Guidelines.

However, particularly for mixtures, it is expected that calculation rules for combining information about the components of the mixture and/or estimation techniques will be accepted means of establishing whether or not a given substance will fall above or below the threshold. Examples of such rules include those recommended by the World Health Organisation (WHO).

If there is only one toxic component in a mixture, the LD50 of the mixture (LD50 (mix)) can be taken to be the LD50 of that component (LD50 (comp)) divided by its fractional percentage concentration (P):

If there is more than one toxic component in a mixture, then the LD50 of the mixture may be taken to be the LD50 of the most hazardous component at the total concentration of all the active components. This can be used when some of the LD50's of the mixture are unknown.

If the LD50's of all the components are known, the LD50 of the mixture may be calculated by the formula:


where n is the number of acutely lethal components, and Pi is the fractional weight percentage of component i.

The same approach as above can be used for the calculation of LC50's of mixtures.

It should also be noted that older studies/methods may still provide useful information for the above measure but may predate currently accepted Good Laboratory Practice (GLP). Again, it is not envisaged that information obtained from these studies would be excluded from consideration.
7.4.2 Cut-off values for acute toxicity

For oral toxicity, present European requirements may appear to be for a cut-off of 2000 mg/kg but they include within regulated systems any mixture containing more than 25% of a component above this cut-off. As the HSNO Act does not differentiate between "pure" chemical entities and mixtures, adoption of this approach would mean substances with an acute toxicity of less than or equal to 8000mg/kg would fall within the threshold. The US system generally uses a cut-off figure of 5000mg/kg. There are similar values for acute toxicity for inhalation.

The AG-HCL technical documents have established the specifications listed in part (1) of the specification as the lower cut-off level and these have been adopted accordingly.

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8 The threshold for substances with ecotoxic properties

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8.1 General approach taken for ecotoxic properties.

The ecotoxic threshold criteria are derived from two sources:

  • for aquatic ecotoxicity, the documents of the AG-HCL.
  • for terrestrial ecotoxicity, the scheme used by the US EPA.

This approach has been taken as the matter of terrestrial ecotoxicity has not so far been addressed as part of the international harmonisation exercise.

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8.2 Elements of the ecotoxic threshold.

There are 5 elements of the threshold for substances with an ecotoxic property:

  1. Aquatic toxicity
  2. Effects on the soil environment
  3. Effects on terrestrial vertebrates
  4. Effects on terrestrial beneficial invertebrates
  5. Biocidal action
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8.3 Ecotoxic threshold technical description

A substance triggers the threshold for ecotoxic effects if it is more toxic than any one of the threshold levels in sections 8.3.1 - 8.3.5.

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8.3.1 Ecotoxic to the aquatic environment

a) Either the acute fish (96 hour) LC50 is £ 100 mg/l
or
the crustacean (48/96 hour) EC50 is £ 100 mg/l
or
the algae (72/96 hour) EC50 is £ 100 mg/l


or

b) the chronic fish or crustacean no observable effect level (NOEC) is £ 1 mg/L.

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8.3.2 Ecotoxic to the soil environment

a) a plant or soil invertebrate EC50 £ 100 mg/kg dry weight of soil

or

b) a 25% reduction of microorganism respiration or nitrification at £ 100 mg/kg dry weight of soil.

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8.3.3 Ecotoxic to terrestrial vertebrates

a) an avian or mammalian acute LD50 of £ 2000 mg/kg body weight or acute LC50 of £ 5000 ppm diet

or

b) a chronic avian or mammalian Maximum Acceptable Toxicant Concentration (MATC) £ 100 ppm diet.

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8.3.4 Ecotoxic to beneficial terrestrial invertebrates

A contact or oral LD50 of £ 25 mg/bee.

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8.3.5 Substances designed to cause Biocidal action

Any substance designed for a biocidal action is to be considered by ERMA New Zealand.

"Designed for biocidal action" is defined as intended to cause either mortality, inhibited growth, or inhibited reproduction in any organism.

The following substances are excluded from this threshold:

(a) A substance designed for biocidal action against a virus, protozoan or a bacterium; or
(b) A substance designed for biocidal action against internal organisms in man or other vertebrates;
And where the substance is a mixture or formulation, no ingredient of the mixture or formulation in its pure form would be classified as ecotoxic class 1, 2 or 3.

Interpretation of terms

EC50 The concentration of substance that produces either a sublethal response in 50% of an organism population or a 50% reduction in growth or growth rate.

LC50 The concentration of substance lethal to 50% of an organism population.

NOEC The highest concentration of substance that does not have a statistically significant adverse effect on an organism population.

LD50 The dose of substance lethal to 50% of an organism population.

LOEC The lowest concentration of substance that has a statistically significant adverse effect on an organism population.

MATC The geometric mean of the NOEC and LOEC.

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8.4 Notes on the ecotoxic threshold:

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8.4.1 Threshold Tests for Substances with ecotoxic properties

These specifications are limited to those which will permit the use of any test results or estimating methods within any guidelines provided by ERMA New Zealand to establish whether a given substance is captured by the threshold.

It is anticipated that ERMA New Zealand will provide guidance in the final version of this guide as to what test protocols or methods would be recognised as acceptable tests for the specified threshold criteria. It is expected that whatever path ERMA New Zealand chooses, the following test guidelines would met these measures:

OECD Test Guidelines
US EPA Guidelines
EC Guidelines.

However, particularly for mixtures, it is expected that calculation rules for combining information about the components of the mixture and/or estimation techniques will be an accepted means of establishing whether or not a given substance falls above or below the threshold. A more detailed explanation of these rules is given in section 7.4.1.

It should also be noted that older studies/methods may still provide useful information for the above measure but may predate currently accepted Good Laboratory Practice (GLP). Again, it is not envisaged that information obtained from these studies would be excluded from consideration.

It is not envisaged that the full range of ecotoxicity tests described in the thresholds would be required for every substance. In the final version of this guide, ERMA New Zealand will provide guidance notes as to what data set is considered appropriate for different chemical types e.g. agricultural or industrial chemicals.

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8.4.2 Soil compartment and terrestrial vertebrate ecotoxicity

The threshold criteria for these compartments do not specify particular test species and are deliberately written as one criterion or the other. This is done so that only data relevant to that substance may be required. It also acknowledges the relatively less advanced state of development of science in this area. For example, where specific indicator species have not been definitively established or where the relative sensitivity of New Zealand species to the international test species is unknown. The intention is to allow any available results or estimates to act as indictors subject to ERMA New Zealand guidance noted in 8.4.1 above.

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8.4.3 Substances designed for biocidal action

This element is intended to capture all substances which are designed to be biocidal compounds and is included to ensure that these substances can be considered and where necessary controlled to manage environmental effects.

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Appendix A: International Harmonisation

The thresholds have been matched as closely as possible (within the framework provided by the HSNO Act) to the harmonised scheme being developed as a result of the recommendation of United Nations Conference on Environment and Development in Rio, contained in Chapter 19 of Agenda 21. The major technical work in developing the harmonised scheme is being undertaken by two groups:

  • the IOMC subcommittee of the UN Committee of Experts on the Transport of Dangerous Goods (UNCETDG) for physical hazards
  • the Advisory Group on Harmonisation of Classification and Labelling (AG-HCL), a subcommittee of the Chemicals Group in the Organisation of Economic Co-operation and Development (OECD) Environment Directorate.

The thresholds are based as closely as possible on the technical documentation published by these two bodies.

The thresholds for explosiveness, flammability, oxidising capacity and corrosiveness are almost entirely based on the work of the United Nations Committee of Experts on the Transport of Dangerous Goods (UNCETDG) as contained in the UNRTDG Model Regulations, 10th Revised Edition, 1997, and its companion volume UNRTGDH Manual of Tests and Criteria, 2nd Revised Edition, 1995."

The thresholds for toxicity are derived from documents produced by the Advisory Group on Harmonisation of Classification and Labelling (AG-HCL), a subcommittee of the Chemicals Group in the OECD Environment Directorate.

The thresholds for ecotoxicity have been derived from two sources:

  • For aquatic ecotoxicity, the thresholds have been derived from the documents of the OECD's AG-HCL
  • For terrestrial ecotoxicity, the thresholds have been derived from the scheme used by the US EPA (This is because the issue of terrestrial ecotoxicity has not so far been addressed as part of the international harmonisation exercise).

Some minor variations from established international classification systems, or comments on the thresholds, are as follows:

  1. The explosiveness threshold also includes an element to cover substances designed to detonate, deflagrate or produce a pyrotechnic effect. This criterion carries over the current scope of the Explosives Act 1957 and allows coverage of such things as airbag igniters, model rocket engines and primer caps.
  2. The threshold for flammable aerosols has been written to fit the HSNO approach which differentiates between the substance and the controls applied to it. The combination of this threshold together with the controls on flammable aerosols and the requirements for packages is intended to provide an end result equivalent to the approach taken by the UN, EC and ICAO.
  3. The threshold for flammability of liquids of a flash point of 93oC originates from a proposal of the UNCETDG Subcommittee advising the IOMC Co-ordinating Group on flammability.
  4. The threshold level for acute oral toxicity has been set at 5000 mg/kg. This is for a substance, whether it is a single chemical or a formulated mixture. Present European requirements appear to have a cut-off of 2000 mg/kg. However, included in the regulated system are any mixtures which contain components of more than 25% which are above this cut-off level of 2000 mg/kg. As the HSNO Act does not differentiate between single chemical substances and substances which are mixtures of chemicals, this (European) approach would equate to a HSNO threshold of 8000 mg/kg.

The HSNO threshold level for acute toxicity also includes an exclusion clause that a substance is not above the threshold if, "at or below the respective threshold value, reliable data becomes available from human or animal studies, which indicate no statistically significant acute toxic effect."

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