State of knowledge report
Environment Australia, 2001
ISBN 0 6425 4739 4
Appendix A: Chemicals management in Australia
This section provides a general overview of the chemicals management system currently in place in Australia.
It outlines the provisions and the scope of the National Registration Scheme for Agricultural and Veterinary Chemicals and the National Industrial Chemicals Notification and Assessment Scheme (NICNAS). It also elaborates on occupational health and safety, and public and environmental health issues associated with the use of chemicals in Australia.
The following information has been modified from the publication National Profile of Chemicals Management Infrastructure in Australia published by Environment Australia in November 1998. The full document is available on the internet.1
Copies of the relevant legislation may be downloaded from the Australasian Legal Information Institute.2
The chemicals industry makes a significant contribution to the Australian economy. Australian Bureau of Statistics (ABS) data indicate that the chemicals industry had a turnover in excess of A$35 billion in 1995–96 and employed over 80 000 people (ABS 1996).
Table A1 sets out official production statistics for the chemicals industry during 1993–94. It includes quantities of chemicals reformulated or repackaged in Australia.
The agricultural and veterinary (agvet) product sales in Australia were estimated at over $1.6 billion in 1996 (Table A2) (Environment Australia 1998).
Assessment and registration of chemicals takes place at the national level. Control of usage and sales is primarily the responsibility of the States and Territories. The two main national schemes for the management of chemicals are the National Registration Scheme for Agricultural and Veterinary Chemicals, managed through the National Registration Authority for Agricultural and Veterinary Chemicals (NRA) and NICNAS. These schemes assess new and existing chemicals at the national level. They rely on the professional skills of a number of government departments (those with responsibility for the environment, public health and occupational health and safety) to conduct various elements of the risk assessment, thus providing a greater degree of independence and confidence in each assessment. Table A3 provides a summary of the key features of these chemicals assessment approaches.
Other relevant national controls include national environment protection measures (see ‘Other mechanisms’ below).
|Chemical typea||Production (1993-94)|
|Fertilisers||Acids, ammonium and compounds||t||287 000||32.8|
|Animal or vegetable fertilisers||t||99 454||48.0|
|Nitrogenous fertilisers||t||1 116 000||335.3|
|Phosphatic fertilisers||t||1 429 000||304.6|
|Industrial uses||Basic inorganic||t||2 585 000||953.5|
|Miscellaneous basic chemical products||NA||144.6|
|Plastics in primary forms||t||885 000||1230.4|
|Synthetic rubber in primary forms||t||49 000||80.1|
|Tanning or dyeing extracts and derivatives||t||39 971||177.3|
|Other chemicals||Paints, varnishes, artist's colour, ink, etc. (liquid)||ML||192||NA|
|Paints, varnishes, artist's colour, ink, etc. (other)||t||40 645||2136.7 b|
|Other chemical products||t||97 546||1,530|
|Consumer chemicals||Cleaning and toilet preparations (liquid)||ML||84.2||NA|
|Cleaning and toilet preparations (other)||t||375 968||1866.7b|
a Commodities are classified according to the Australian and New Zealand Standard Commodity Classification.
b Combined value for liquid and other.
t = tonnes
ML = megalitres
NA = not available
Source: Environment Australia (1998), National Profile of Chemicals Management Infrastructure in Australia3 (data taken from Manufacturing Production, Australia: Principal Commodities Produced, 1993–94. ABS Cat. No. 8365.0).
|Total agvet sales||1661.9|
|Total agvet sales include the following:|
Source: Environment Australia (1998), National Profile of Chemicals Management Infrastructure in Australia (data provided by the National Registration Authority).
|Element||Industrial chemicals||Agricultural and veterinary products|
|Scheme responsible for assessment||NICNAS.||National Registration Scheme for Agricultural and Veterinary Chemicals managed principally through the NRA.|
|Assessment and/or registration||All new chemicals to be assessed before use. Existing chemicals reviewed on a priority basis.||All new products and new uses of products must be assessed and registered before use. Existing chemicals and products may be reviewed.|
|Scope and definition||Assessment of a chemical entity (not product): Any chemical that has an industrial use may be included (ie dyes, solvents, adhesives, plastics, laboratory chemicals, paints, cleaning products, cosmetics and toiletries). Does not include articles, radioactive chemicals or chemicals solely in other schemes. Can review chemicals that are contaminants or pollutants.||Registration of products includes: an agricultural product which is a substance used to stupefy, repel, inhibit the feeding of or prevent, pests on plants or other things; used to destroy a plant or modify physiology; or attracts pest to destroy it. Veterinary product includes a substance for preventing, diagnosing, curing or alleviating disease in animals. Excludes fertilisers.|
|Controls of use||If not on AICS (or has an assessment certificate or permit issued) may not be used commercially. May be removed from AICS. Application of assessment report recommendations by legislation at State and Territory level through adoption of NOHSC National Model Regulations for Hazardous Substances, and other State/Commonwealth legislation controlling chemicals.||If not registered may not be used. Registration may specify how used. Registration can be cancelled. Use controlled by State and Territory by application of NRA registration advice (labels must be complied with).|
|Supporting legislation||Industrial Chemicals Notification and Assessment Act 1989, OHS Acts, Poisons Acts, Standards||Agricultural and Veterinary Chemicals (Code) Act 1994 and Administration Act 1994, State and Territory complementary legislation.Control of use legislation including Pesticides, Poisons and Food Acts.|
|Advisory products – including labels, assessment reports, safe use advice.||Chemical assessment reports (NICNAS) Exposure standards, labelling, material safety data sheets (NOHSC) Poison schedule classification SUSDP (AHMAC)||Product assessment. Labelling. Maximum residue limits (MRLs), SUSDP-poison schedule classification.|
Source: Environment Australia (1998) (November), National Profile of Chemicals Management Infrastructure in Australia.4
The Commonwealth's Industrial Chemicals (Notification and Assessment) Act 1989 (ICNA) provides for a national scheme for the notification and assessment of industrial chemicals. NICNAS was established in 1990 and is administered by the National Occupational Health and Safety Commission (NOHSC).5
The assessment processes are different for existing and new chemicals.
The assessment process for a new chemical begins with a primary toxicological assessment conducted by NICNAS staff and an environmental assessment conducted by Environment Australia for NICNAS. These form the basis for further assessments relating to occupational health and safety, public health (conducted by the Department of Human Services and Health) and the environment.
NICNAS commenced only in 1990, so most of the more than 40 000 chemicals on the Australian Inventory of Chemical Substances (AICS)6 have never been formally assessed. Therefore, NICNAS provides for the declaration of existing chemicals that are of most concern; these are called priority existing chemicals because of their potential for adverse effects on occupational health and safety, public health or the environment.
The public may nominate chemicals to be included in the priority existing chemical selection process. Nominated chemicals are screened and ranked against predetermined selection criteria. Declaration of a priority existing chemical is made by the Minister for Employment, Workplace Relations and Small Business. Chemicals that do not have to be notified as new chemicals, either because they are listed on the AICS or because they are exempt from notification, may also be selected and assessed under the priority existing chemicals program. NICNAS can assess air toxics where the chemical is not used solely as a therapeutic or pesticide.
NICNAS compiles the assessments of new and existing industrial chemicals into reports that are sent to interested Commonwealth, State and Territory authorities. Assessment reports may make recommendations, including any restrictions or precautions relating to:
- import, handling, storage, use and disposal;
- packaging, labelling and the material safety data sheets (developed by industry and approved by the government) relevant to the range of standards; and
- permissible concentrations in emissions to air or water.
These recommendations may then be adopted by authorities as part of their control of the use of industrial chemicals.
Existing industrial chemicals
For existing industrial chemicals, the data requirements depend on the assessment type. A standard dataset for a full-priority existing chemical comprises information confirming the identity of the chemical, the physicochemical properties and use of the chemical (including import/manufacture volumes), all available toxicological/epidemiological data, detailed exposure information for workers, the public and the environment and risk management initiatives. The toxicological package includes available human, animal and in vitro data and ecotoxicity and biodegradability/fate data for the environmental assessment.
The dataset for a preliminary priority existing chemical may or may not include a detailed toxicological package or detailed exposure data. Risk assessment, in terms of a formal risk characterisation for specific uses is not carried out for preliminary assessments.
|PEC candidate (may be assessed in future)|
|Boron and compounds||7440-42-8|
|1,3- Butadiene (vinyl ethylene)||106-99-0|
|Chromium (VI) compounds||7440-47-3|
|Di-(2-ethylhexyl) phthalate (DEHP)||117-81-7|
|Formaldehyde (methyl aldehyde)||50-00-0|
|Methyl ethyl ketone||78-93-3|
|Nickel and compounds||7440-02-0|
|Xylenes (individual or mixed isomers)||1330-20-7|
|PEC assessment under way|
|Tetrachloroethylene (also a previous candidate PEC chemical)||127-18-4|
|PEC assessment finalised|
|Asbestos (full PEC report on chrysotile + PIC DGD on crocidolite)||1332-21-4|
PEC = priority existing chemical
PIC = prior informed consent
DGD = decision guidance document
The dataset for a secondary notification assessment is determined in accordance with a set of criteria as set out in the Industrial Chemicals (Notification and Assessment) Act 1989. Should these circumstances require a re-evaluation of the risks assessed in the original priority existing chemical report, a formal risk characterisation is usually carried out.
Under the Industrial Chemicals (Notification and Assessment) Act 1989 applicants have a statutory obligation to provide occupational exposure data for assessment. This information is supplemented from literature review, site visits, international reports (eg Organisation for Economic Co-Operation and Development screening information dataset initial assessment reports, or OECD SIARs) and, where data are lacking, from modelling. The model that has been used to date is the United Kingdom Health and Safety Executive estimation and assessment of substance exposure (EASE) model, which provides estimates of airborne and dermal exposure for different occupational scenarios.
Where exposure by inhalation is the major route of exposure and the toxicological database includes good-quality inhalation data (human or animal), the common practice is to use ‘external’ exposure data in the risk characterisation process (see below) rather than attempting to extrapolate to ‘internal’ dose. When external exposure data are used/determined, no adjustment is made to account for reduced personal exposures resulting from the use of personal protective equipment (eg respiratory protection, gloves etc). However, where mechanical ventilation is installed, this can be factored into the EASE model, should suitable monitoring data (ie measured when ventilation has been installed and is operational) not be available. The quality of the monitoring data should also be a factor considered in the risk characterisation and exposure standard setting processes (see below).
Where dermal exposure is an important route of exposure and/or where the toxicological database does not provide an inhalation study, internal (dose) exposure may be estimated, utilising the available pharmacokinetic data, and used in the risk characterisation process.
Under the Industrial Chemicals (Notification and Assessment) Act 1989, applicants have a statutory obligation to provide toxicological and epidemiological/case-study/clinical data for assessment. The data are supplemented from literature review and international reports (eg the OECD SIARs or reports from the International Program on Chemical Safety, International Agency for Research on Cancer, and European Centre for Ecotoxicology and Toxicology of Chemicals).
Currently, available toxicological and epidemiological data are evaluated in conjunction with available pharmacokinetic data, to estimate the critical no observable adverse effect level (NOAEL). If the NOAEL has not been determined, the lowest observable adverse effect level (LOAEL) is estimated for both acute and chronic exposures for each relevant route of exposure (ie oral, dermal and inhalation). The health hazards for each endpoint are classified in accordance with the NOHSC Approved Criteria for Classifying Hazardous Substances.
The quality of the toxicological database should be a factor considered in the risk characterisation and exposure standard setting processes (see below).
NICNAS uses the ‘margin of exposure’ (MOE) approach to risk characterisation.
In deriving the MOE, the critical NOAEL is compared directly with the measured/estimated exposures for each occupational scenario of relevance to manufacture and use in Australia. This is carried out separately for inhalation and dermal exposure (where relevant) by using NOAELs derived specifically from each route of exposure.
Where exposures may be significant by both routes, the combined estimated internal dose may be used. In this case, the oral NOAEL (for the critical effect) is usually considered more appropriate for deriving the MOE.
The resulting MOE is evaluated for each route, taking into account the quality of the available database (eg whether derived from human data, uncertainties in the database etc) and the nature/severity of the effect (eg carcinogen, sensitiser, etc). No specific values are assigned to component uncertainty factors; this is usually part of the exposure standard setting process carried out by the NOHSC (see below). However, the risk characterisation process takes these uncertainties into account in evaluating the adequacy of the MOE.
Based on the magnitude of the MOE, current risk management initiatives are assessed; where found inadequate, recommendations for additional exposure reduction measures (controls) or other risk management initiatives are promulgated. Recommendations may include regulatory action by the NOHSC or other agencies (eg the Therapeutic Goods Administration [TGA] and Environment Australia, where public health and environmental risks have been identified). Recommendations to the NOHSC may include the setting of an occupational exposure standard (see below), review of an existing exposure standard (see below), scheduling of a substance in accordance with the model regulations for control of workplace hazardous substances and, as a last resort, phase-out of use and manufacture.
New industrial chemicals
For new industrial chemicals, the data requirements depend on the notification category and are stipulated under the Industrial Chemicals (Notification and Assessment) Act 1989. A standard dataset comprises information confirming the identity of the chemical, the physicochemical properties and use of the chemical, detailed exposure information about how workers, the public and the environment are exposed to the chemical, and a standard toxicological package. The toxicological package includes animal and in vitro data for the human health assessment and ecotoxicity and biodegradability data for the environmental assessment.
The occupational exposure assessment is conducted by establishing the use pattern of the chemical and identifying the sources of occupational exposure. Exposure is then estimated by taking into account the routes of exposure, the frequency and duration of exposure, and measured worker data (eg atmospheric and/or biological monitoring results). Information is needed for each of the scenarios where workers are potentially exposed to the chemical.
For new industrial chemicals, the occupational exposure assessment is usually qualitative, as measured data are unlikely to be available and there is insufficient information available to predict reliable quantitative estimates. EASE modelling is occasionally used.
Both human and experimental animal data are assessed in accordance with international guidelines to identify the critical health effects of the chemical and to determine the dose-response relationship, with NOAELs established wherever possible. For new industrial chemicals, human data are usually not available. The health hazards of the chemical are classified in accordance with the NOHSC-approved criteria for classifying hazardous substances.
For new chemicals, the toxicological database may consist of studies that have been performed with a structural analogue of the notified chemical, or with a formulation. Adequacy and applicability of the data will be taken into account when performing the assessment. Where data gaps exist, or where toxicological data have not been provided, as with some classes of polymer, the toxicological hazard may be predicted from the chemical's physical properties or the characteristics of structurally related chemicals, given that factors such as volatility, solubility and molecular weight can indicate the likely extent of absorption across biological membranes.
The health risk to workers is characterised by integrating the occupational exposure and toxicological assessments. For brief or short-term exposures, human data and information from acute toxicity studies in animals are taken into account to determine the risk of adverse health effects such as acute respiratory effects and skin irritation. For longer-term and repeated exposures, the health risk to workers is characterised initially by comparing exposure estimates with NOAELs to give an MOE, and then deciding whether there is cause for concern.
Matters taken into account when characterising the risk include the uncertainty arising from the variability in the experimental data, and interspecies and intraspecies variation, the nature and severity of the health effect and its relevance to humans and the reliability of the exposure information.
Where it is not possible to determine a NOAEL or a LOAEL (eg because there are no suitable data), the risk is evaluated on the basis of qualitative or quantitative exposure relevant to the group of workers being considered. For new chemicals, a more qualitative characterisation takes place, as exposures are often unknown or more difficult to predict.
The NRA was established by the Agricultural and Veterinary Chemicals (Administration) Act 1992. In 1994, the Commonwealth, State and Territory governments provided the NRA with extensive powers related to agvet products through each jurisdiction's agricultural and veterinary chemicals acts.
The registration scheme provides for the NRA to control agvet products up to and including the point of sale. States and Territories are responsible for the control of use of agvet products beyond the point of sale. These separate components are addressed by different organisations according to areas of expertise and responsibility.
The NRA evaluates the chemistry and efficacy of products and the presence of residues in food. The NRA also receives professional advice in the form of risk assessments from the Department of Health and Aged Care (on human health effects), Environment Australia (on environmental impacts) and the NOHSC (on worker safety).
Before new agricultural or veterinary chemicals can be approved for marketing, companies are required to conduct the following studies:
- detailed and extensive toxicological testing in laboratory test animals (as surrogates, or models, for possible toxic effects in humans);
- toxicological investigations on organisms and animals in the environment, to assess possible unintended effects on beneficial insects, fish, birds, etc;
- field trials to determine the likely dermal and inhalation exposure of agricultural workers using the chemical, as well as estimates of possible bystander exposure; and
- field trials to determine likely residues in crops, in order to estimate the possible dietary exposure of the general population to the chemical.
The task of assessing the toxicity of a chemical and the potential for human exposure to it, either occupationally from ingestion of residues in food or through domestic use in the home and the garden, is called chemical risk assessment.
Australia introduced a formal program to systematically review existing agricultural and veterinary chemicals in 1994. It is called the Existing Chemicals Review Program and is managed by the NRA. It is one of a number of initiatives arising from a 1990 government inquiry into aspects of the legislative, administrative and regulatory procedures for agricultural and veterinary chemicals. The Existing Chemicals Review Program was needed largely because many registered chemicals in the marketplace had been assessed according to criteria that are outdated by today's regulatory standards. The program involves cooperative arrangements between the Chemicals Unit of the TGA (public health), Environment Australia (environment), the National Occupational Health and Safety Commission (occupational health and safety [OHS]) and the NRA (agricultural issues, including efficacy, crop residues, etc).
The goal of the program is to ensure that agvet chemicals in use in Australia can be used safely and effectively. The program operates according to the principles of openness, fairness and consistency with regard to public consultation, selection of chemicals for review, and standards of assessment. All aspects of a chemical (public health, occupational health and safety, environmental, efficacy, and animal and crop safety) are considered in a review. Thus, the Existing Chemicals Review Program has been implemented to:
- ensure that the chemicals remain safe and effective when used according to label instructions by specifically considering toxicity and exposure patterns in relation to public health, occupational health and safety, known and potential environmental impacts, efficacy, safety issues in relation to target species (animal and crop) and management options to reduce identified risks;
- maintain the protection of Australian trade and commerce in agricultural produce and livestock;
- address community concerns and general interest in agricultural and veterinary chemicals by providing information to the public on the use of chemicals and their environmental, public health and OHS aspects; and
- consider public nomination of chemicals for review.
Special reviews can be conducted by any of the participating agencies as the need arises.
Environment assessment Sustainable Industries and Atmosphere Division process
The of Environment Australia is responsible for assessing the environmental impacts of agvet chemicals. It assesses information provided by the company, and information from other sources (eg literature searches, United States Environmental Protection Authority reports, the OECD Environment Committee chemicals program, publications of the International Programme on Chemical Safety, information from State agencies). In this way, it determines:
- the degree of environmental exposure;
- the toxicity of the chemical to aquatic organisms (and terrestrial organisms, birds, and desirable vegetation as applicable); and
- the overall environmental hazard of the chemical, which takes into account both exposure and toxicity.
It then considers what action, if any, should be taken to minimise the assessed environmental hazard.
As a result of these considerations, Environment Australia may make recommendations to minimise environmental hazards. It may request further data, monitoring trials, specific controls or label instructions and warnings that will reduce the risk.
The company seeking registration of an agvet product is required to provide information on:
- its physical and chemical properties;
- the formulation of the end-use product;
- environmental release (application method, use, volume, geographic location);
- environmental chemistry and fate — hydrolysis (reaction with water), photolysis (degradation by light), degradation in soil and water, mobility in soils, field dissipation, accumulation in soils); and
- environmental toxicity to relevant organisms such as birds, aquatic organisms (algae, invertebrates and fish), nontarget invertebrates, mammals and vegetation.
The Department of Health and Aged Care evaluates the human toxicology of the product and determines poison schedule classification and first-aid and safety directions.
Toxicologists assess the toxicity (or hazard) of a pesticide and then compare estimates of likely human exposure to it with an acceptable (or ‘safe’) health standard determined from the package of toxicology studies conducted on animals in vivo and on cell and tissue systems in vitro.
People may suffer from acute pesticide poisoning arising from accidental ingestion (especially in children) or deliberate ingestion (in cases of suicide or attempted suicide). However, people are usually exposed by ingesting food containing low residue levels from pesticides used to treat food commodities. Those who live near agricultural areas where pesticides are applied by ground or aerial spraying may be exposed by inhalation or by absorbing the substance through the skin. People may also be exposed through the use of pesticides in and around the home (eg subfloor termiticide barriers, household insecticide sprays, and dusts and sprays for fruit trees, vegetables and ornamentals).
In considering the possible health effects arising from the ingestion of residues of a particular pesticide, it is important to determine the acceptable daily intake (ADI) of that pesticide that is considered to be ‘safe’ over a lifetime exposure (ie without any adverse effects on health). This is usually based on information derived from toxicology studies carried out in experimental animals. The most suitable studies for the derivation of an ADI are long-term studies in experimental animals. These studies involve regular daily intake of the chemical under investigation, mimicking the exposure resulting from ingestion of food containing low levels of pesticide residues.
A comprehensive package of toxicology studies allows the determination of the daily dose of a pesticide or test chemical that can be given over a certain period of time by a particular dose route, at which no adverse effects are observed. The NOEL or NOAEL is selected from the most appropriate study or (commonly) the lowest value is selected from several relevant studies. The NOEL can be simply defined as the highest determined dose of a substance that causes no changes distinguishable from normal (control) animals.
Once established, the lowest (or most appropriate or relevant) NOEL (or NOAEL) derived from animal toxicology testing is used to set an ADI for humans. This is done by dividing the NOEL or NOAEL (expressed in terms of milligrams of test chemical per kilogram of bodyweight per day) by a safety factor, which is conservatively chosen to allow what is considered to be a more than adequate margin of safety. Safety factors are not rigidly applied. When NOELs are based on studies in animals, a safety factor of 100 is usually used to derive an ADI; this is made up of a factor of 10 for interspecies extrapolation and an extra factor of 10 to allow for variations between individuals in human populations. A safety factor of only 10 may apply if a NOEL can be derived from an appropriate test conducted in humans. Further safety factors may be incorporated:
- to provide additional protection for special risk groups (eg infants);
- where the toxicological database is not complete or there are some concerns about its quality; or
- where the nature of the potential hazards indicates the need for additional caution.
The safety factor approach is based on the assumption that exposure at less than the ADI is without appreciable risk. In other words, there is a presumption of a threshold dose below which no effects of concern are likely to occur. No attempt is made to quantify the level of risk.
In Australia, toxicology and public health assessments are performed by toxicologists within the Chemicals Unit of the TGA, an agency that is part of the Department of Health and Aged Care. In addition to assessing applications for approval of new pesticide active ingredients (so-called technical-grade active constituents), toxicologists also assess formulated products containing these active ingredients. Following the hazard assessment, the Chemicals Unit recommends first-aid and safety directions (in liaison with the NOHSC). It also recommends appropriate poisons schedules for the pesticide and its various formulated products; poisons schedules are formally recommended by the National Drugs and Poisons Schedule Committee, a federal committee with representation from all states and territories. The recommendations of the committee are published by the Commonwealth under the Therapeutic Goods Act 1989, in the Standard for the Uniform Scheduling of Drugs and Poisons.
The Chemicals Unit also re-reviews older pesticides that have been on the Australian market for many years.
The Agricultural and Veterinary (Agvet) Section of the NOHSC evaluates products from an occupational health and safety viewpoint and determines safe handling and use practices in the workplace (at manufacturing, distribution and end-use levels), including the need for protective clothing. The OHS risk assessments are conducted under two programs, ‘Product Registration’ and ‘Chemicals Review’, and in accordance with the outline presented below.
The OHS assessment of agvet chemical products requires the following data:
- use pattern of the product;
- formulation composition of product;
- physicochemical properties of the active constituent and product;
- toxicology of the active constituent and product; and
- exposure data.
The Agricultural and Veterinary Chemicals Code Act 1994 requires applicants to provide the NRA with all available exposure data and adverse incident reports, for assessment. Exposure data may cover manufacture/formulation of agvet products and end-use situations. This may be supplemented by information from literature reviews, international reports (eg from the United States Environmental Protection Authority and the UK Ministry of Agriculture, Fisheries and Forestry), field/site visits and modelling. The model used to date is the UK Predictive Operator Exposure Model (POEM). Occasionally, exposure data from the United States Pesticide Handlers Exposure Database (PHED) have been used where applicants provide subset exposure data.
In undertaking the exposure assessment of a product, the NRA considers the use pattern, potential exposure scenarios and predominant routes of exposure. For agvet chemicals, skin contamination is the main route of exposure. Inhalation exposure is less common except when the product is applied in an enclosed space (eg fumigants). Therefore, where the toxicological database includes dermal dosing studies of appropriate quality and duration, these data are used in the risk characterisation process.
If there are no appropriate dermal studies, the internal dose is estimated using external dermal exposure data corrected for dermal absorption. Absorption is estimated using in vitro and/or in vivo percutaneous absorption data. Analogue data may be used if there are no chemical-specific data. Total body burden is determined by integrating exposure from inhalation and dermal routes and comparing the result with systemic effect data to ascertain potential health risk.
Where biomonitoring data are available, a biological monitoring approach may be used, as absorbed dose data interpreted with the aid of pharmacokinetic data are likely to be more accurate than the estimation of internal dose given by exposure data corrected for dermal and respiratory penetration.
Pesticide exposure assessments also take into consideration the protection afforded by label specified protective equipment. Default protection factors are utilised in the absence of specific data.
The TGA evaluates toxicological, epidemiological and case-study data provided by applicants. The TGA evaluation is used in determining relevant endpoints and NOELs or LOELs for use in the OHS risk assessment. The quality of the database, the frequency of use of the product, the health significance of the endpoints and the predominant route of exposure are taken into account.
For new agvet chemicals, the health hazards of the chemical are classified in accordance with the NOHSC approved criteria for classifying hazardous substances.
The risk assessment takes into consideration the hazard of the chemical and the potential for occupational exposure. An end-use risk assessment is usually conducted for agvet products. Potential exposure is determined by the use pattern of the product and current agricultural/animal husbandry practices (including existing exposure mitigation methods such as protective equipment and engineering controls).
As for industrial chemicals, agvet assessments use the MOE approach. The benchmark MOE is determined on a case-by-case basis, following consideration of the quality of the database, the nature and severity of the health effect and the known variability in human metabolism of the chemical. In general, a 10-fold factor is considered appropriate to account for interspecies extrapolation and a similar factor for intraspecies variability.
Current exposure mitigation methods are evaluated quantitatively, where possible. In the absence of data or models, qualitative assessments are conducted based on generalised information about the use pattern and ‘scientific judgement’. Where current exposure assessment methods are found to result in unacceptable risk, additional exposure and risk reduction methods may be recommended.
OHS recommendations on regulatory action may include restrictions on use of the chemical, exposure mitigation methods in accordance with the hierarchy of controls under hazardous substances legislation or review of an existing exposure standard.
Control of use
The States and Territories are responsible for controlling the use of agvet chemicals once they have been sold, and for guiding users on the use of agvet chemicals. The activities of the States and Territories encompass regulatory, educational and research activities. The specific regulatory mechanisms used for controlling the use of agvet chemicals vary from jurisdiction to jurisdiction.
The NOHSC requires occupational health hazards to be controlled according to the national Exposure standards for atmospheric contaminants in the occupational environment (Guidance note and national exposure standards (p1003). These are guidelines to be used in the control of occupational health hazards; they are not dividing lines between safe and dangerous concentrations of chemicals, or a measure of relative toxicity. The national exposure standards are set out in regulation 12(4) of the NOHSC Control of workplace hazardous substances (national model regulations) 1994 at p1005; this regulation deals with employers' duties and the control of exposure provisions. Appropriately qualified and experienced persons should interpret the standards.
The Commonwealth, States and Territories have uniform hazardous substance legislation based on the national model regulations.
In 1999, the NOHSC changed the way it reviews and updates the national exposure standards. The new method maximises the use and acceptance of overseas standards from government and nongovernment sources, and minimises the need to develop standards in Australia.
Primary sources include the United Kingdom Health and Safety Executive Occupational Exposure Limits, the American Conference of Governmental Industrial Hygienists Threshold Limit Values, the German Government Maximale Arbeitsplatz-Konzentration (MAK) values and European Union standards.
These sources were selected after assessment against several criteria, including quality and availability of supporting documentation, integrity of the development process and consistency with the NOHSC philosophy of transparency, development through consultation, and scientific robustness.
Use of toxicological/exposure database
The NOHSC also allows overseas standards to be used to review the toxicological data. The process is designed to minimise reassessment of toxicological data, relying instead on the integrity of the development process and the inherent sound science of the overseas system.
Systems chosen represent an appropriate evaluation of available toxicological and epidemiological data sources by acknowledged agencies.
Where de novo standards are to be developed, the NOHSC Hazardous Substances Subcommittee determines the broad parameters of the data requirements for review, without limiting the range of toxicological data to be used by, for example, a consultant reviewing a national exposure standard.
The following are regarded as appropriate sources for risk assessment consideration in any review, and would continue to be employed: the NICNAS priority existing chemical reports; supporting documentation from the United Kingdom Health and Safety Executive, the American Conference of Governmental Industrial Hygienists and the German Government Maximale Arbeitsplatz-Konzentration; overseas scientific publications such as reports of the European Centre for Ecotoxicology and Toxicology of Chemicals, IPCS reports, environmental health criteria, concise international chemical assessment document reports, International Agency for Research on Cancer monographs, and criteria documents from the Nordic Expert Group.
Factors considered in standard setting
Health-based standards are set on the basis of one or more critical endpoints (eg carcinogenicity, irritation). Where available, NOAEL levels for the critical effect can be used as the basis of the standard. Arbitrary safety factors (margins of safety) may be applied to the standard, and examples of 33–50% of the value of an observable effect level (animal or human data) have been recommended on occasion.
All national exposure standards are subject to an impact analysis, the depth of which varies with the estimated impact of the proposed change to the standard, following a review. From a qualitative impact analysis of identifying where additional costs and benefits would be borne as a result of a change in the standard, through to a full economic impact analysis, the NOHSC requires all changes to include this consideration.
Commonwealth and State/Territory Governments
The Commonwealth Government takes the national lead on environment protection or public health when an international treaty, obligation or recommendation requires action. Examples include the control of import and export of ozone-depleting substances under the Montreal Protocol on Substances that Deplete the Ozone Layer, and the prevention of hazardous waste exports under the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes. However, in these situations, States and Territories may support and reinforce Commonwealth activity by instituting their own regime of controls (eg the ozone depletion control acts in each State and Territory).
State and Territory governments develop mechanisms to control the release of chemicals into the environment to protect both public health and the environment. They identify chemicals (including classes of chemicals) that can be released to the environment under certain operating conditions in their respective jurisdictions. State and Territory governments also specify chemicals that may not be released into the environment.
States and Territories adopt a range of mechanisms to manage these chemical releases. Some mechanisms require emitters to pay by the amount of substance they release (polluter pays), thus determining the total load released to the environment in a given area. Other systems prescribe fixed fees or encourage facilities to adopt best-practice control systems with lessening regulation as an incentive. The range of legislation addressing this activity is set out in the National Profile of Chemicals Management Infrastructure in Australia produced by Environment Australia in 1998.
National Environment Protection Council
The National Environment Protection Council (NEPC) stems from the Special Premiers Conference held in October 1990. At this conference the Prime Minister, Premiers and Chief Ministers agreed to develop an Intergovernmental Agreement on the Environment, which came into effect on 1 May 1992.
The agreement includes provision for the establishment of a national body with responsibility for making environment protection measures with the objectives of ensuring that:
- the people of Australia enjoy the benefit of equivalent protection from air, water and soil pollution and from noise, wherever they live; and
- decisions by businesses are not distorted and markets are not fragmented by variations between jurisdictions in relation to the adoption or implementation of major environment protection measures.
Complementary legislation establishing the NEPC has been passed in all jurisdictions. The NEPC is a statutory body with law-making powers established under the NEPC Act 1994 (Commonwealth) and corresponding legislation in the other jurisdictions.
The NEPC has two primary functions:
- to make national environment protection measures (NEPMs); and
- to assess and report on their implementation and effectiveness in participating jurisdictions.
The Ambient Air Quality, Controlled Waste and National Pollutant Inventory national environment protection measures are examples of measures that have already been made. The identification and management of contaminated sites is another area where governments are acting to protect the environment and human health by developing a national approach to this issue.
6 AICS began as a listing of all industrial chemicals used in Australia between 1 January 1977 and 28 February 1990 and subsequently has had new chemicals added to it. All chemicals on the AICS are defined as existing, while any industrial chemical not included in the AICS is regarded as a new chemical. Any new industrial chemicals being introduced into Australia must be notified and/or assessed by NICNAS.
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