Consumers exposure assessment

Additionally, organotin-catalysed silicones have been used in products such as coatings on baking paper (for use in food preparation), and this use is considered in more detail in the consumer exposure assessment (section 6). Information provided by the Centre Europeen des Silicones (CES, 2002b) indicated that organotin-catalysed silicones are used in only a small proportion of baking paper produced in the EU ... 

Environmental exposures form the basis for determining indirect exposures to the general public that will usually occur during a lifetime. Direct consumer exposure assessments prove equally challenging, and may vary from acute to chronic exposure scenarios. Ideally the data set for consumer exposure from a substance in a product should include [127] ... 

Based upon the various sources of adult consumer exposure to organotin compounds (section 6) and the TDI values derived above, it is possible to estimate the relative exposure from the various organotin compounds expressed as a percentage of the TDI values. The exposure calculations in section 6 were based on a realistic worst-case exposure assessment. Table 26 presents the results of this risk characterization. 

For human health risk assessment, it is necessary to elaborate realistic scenarios. Knowledge of real scenarios where the contaminant is emitted to the environment will help to obtain information about the fate and transport of the contaminant once emitted to the environment and the route of exposure for the human beings living in this scenario of concern. There are different types of exposure, i.e., direct, indirect (as is the case of food contaminated by the air, water, or soil contaminated by the emission), occupational exposure, and consumer goods coming from outside the scenario of concern. Depending on the objective of the study, it will be necessary to consider in the exposure assessment one or more types of exposure. 

ECHA (2010) Guidance on information requirements and chemical safety assessment -Chapter R.15 Consumer exposure estimation. Version 2... 

Al-Yakoob, S.N., T. Saeed, and H. Al-Hashash. 1994. Polycyclic aromatic hydrocarbons in fish exposure assessment for Kuwaiti consumers after the Gulf oil spill of 1991. Environ. Int. 20 221-227. 

Exposure assessment a) For the human population, workers, consumers and indirect exposure via the environment b) For the different environment compartments likely to be exposed to the substances water, sediment, soil, and air ... 

The dangerous properties of acute toxicity, irritation, corrosivity, sensitisation, repeated-dose toxicity and CMR are evaluated in terms of their potential toxic effects to workers, consumers and man exposed indirectly via the environment, based on the use for each stage in the lifecycle of the substance from which exposure can occur. Risk assessment is also required if there are reasonable grounds for concern for potential hazardous properties, e.g., from positive in vitro mutagenicity tests or structural alerts. The risk assessment involves comparing the estimated occupational or consumer exposure levels with the exposure levels at which no adverse effects are anticipated. This may be a quantitative risk assessment, based on the ratio between the two values, or a qualitative evaluation. The principles of human health risk assessment are covered in detail by Illing (a.30) and more briefly in Chapter 7 of (73). 

If it is necessary to conduct a risk assessment relating to a specific source of lead (let us say a suspect public drinking water supply), the typical risk assessment would require the development of an exposure assessment relating to that specific source. This ordinary type of assessment would result in some estimate of the range of daily doses (pg/kg b.w.) that individuals using the water could incur. But that dose estimate has no direct utility (1) there are no RfDs developed for specific sources, but rather the target for health protection is based on a blood lead level and (2) the individuals consuming water are no doubt exposed to other sources of lead that contribute to health risk. 

The existing substances ordinance only introduced obligations for substance manufacturers to provide information to the authorities, but not for substance consumers. This resulted in systematic gaps or practice-remote worst-case scenarios in exposure assessment. 

OECD has not published any guidelines for exposure assessment for workers or consumers. 

An OECD Guidance Document on Reporting Summary Information on Environmental, Occupational and Consumer Exposure (OECD 2003b) provides guidance for the reporting of summary exposure information (quantitative and qualitative), which can be used in various chemical assessment programs. 

The European Commission s Joint Research Centre (on behalf of DG S ANCO) has started a project known as European Information System on Risks from Chemicals Released from Consumer Products/Articles (EIS-ChemRisks) (EU 2004), which is designed as a network to collect exposure data, exposure factors, exposure models, and health-related data. The overall objective is to develop tools and reference data to enable harmonized exposure assessment procedures in the EU. A toolbox has been designed to collect exposure information from four reference systems to systematically support exposure assessors in the EU ... 

The EU Technical Guidance Document (TGD) for risk assessment of new and existing substances and biocides (EC 2003) contains guidance on exposure assessment (Chapter 2). The core principles of human exposure assessments according to the TGD are humans may be exposed to substances in the workplace (occupational exposure), from use of consumer products (consumer exposure),... 

In a first screening step of the exposure assessment, the likelihood of an exposure of the three populations (workers, consumers, and man indirectly via the environment) to the substance under consideration has to be evaluated. If in the screening step it is indicated that exposure to one or more of the human populations does not occur or when the expected exposure is so low that it can be neglected further in the risk characterization phase, no further assessment is needed and the conclusion can be mentioned in the risk assessment report. 

As mentioned above, the exposure assessment of new and existing substances is carried out separately for three subgroups of the human population workers, consumers, and man exposed indirectly via the environment (EC 2003). 

The risk characterization is carried out by quantitatively comparing the outcome of the hazard (effects assessment) to the outcome of the exposure assessment, i.e., a comparison of the NOAEL, or LOAEL, and the exposure estimate. The ratio resulting from this comparison is called the Margin of Safety (MOS) (MOS = N(L)OAEL/Exposure). This is done separately for each potentially exposed population, i.e., workers, consumers, and man exposed via the environment, and for each toxicological endpoint, i.e., acute toxicity, irritation and corrosion, sensitization, repeated dose toxicity, mutagenicity, carcinogenicity, and toxicity to reproduction. 

Exposure scenarios specify the conditions in which the chemical is to be used (including the protective equipment to be used, working practices, products it is incorporated into, how consumers use those products and how these are disposed), limiting the range of the conditions that must be considered in the exposure assessment. The exposure scenario is annexed to the chemical safety data sheet that is passed to downstream users of the chemical. Those downstream users are required to pass information back to their suppliers about their use of the substance, the exposure to the substance involved in that use and the practicality of specified risk reduction measures. If a use is significantly different from those identified in the CSA, the user must report this to the European Chemicals Agency and prepare its own CSA, or ask the manufacturer to revise the CSA to include that use. 

Workers may be exposed to ENMs during the production, use, or recycling of industrial nanoproducts, and consumers may be exposed mainly during the use of consumer products. However, sooner or later these ENMs are likely to enter the environment and therefore assessing occupational and consumer exposure forms the basis for assessing the environmental exposure. Direct exposure of the environment to ENMs will be mainly restricted to a few applications with intended release... 

In the exposure assessment stage, qualitative and quantitative evaluation of the likely intake of drug residues through food as well as exposure from other sources are performed. Estimating consumer exposure is based on the daily consumption of a particular food commodity combined with its content of veterinary drug residues. 

Risk characterization, the final stage of risk assessment, sets out to provide a qualitative and/or quantitative estimate, given the uncertainties of assessment, the probability of occurrence, and the severity of known or potential adverse health effects in a given population based on hazard identification, hazard characterization, and exposure assessment. The aim is to characterize the risks to the consumer from residues possibly present in animal products on the basis of use of the substance and particularly the withdrawal period, given that the period of administration and the dosage are predetermined by the objective of effectiveness. 

The conditions under which the drug is used need to be estimated as do acceptable residues linked to the level of acceptable risk to the consumer. The acceptable level of risk, which is determined in theory at the risk management stage, has already been expressed in terms of residues by the ADI under hazard characterization. Moreover, the elements considered for hazard identification, hazard characterization, and exposure assessment make it possible, for a given form of utilization of a particular substance, to establish a profile of residues in animal tissues and to associate this with a profile of consumer exposure. Comparison of this consumer profile and ADI indicates whether the mode of utilization of the substance is acceptable or not. Analysis of the different results of residue content in animal products then provides an indication of level of residues in one or several animal tissues, making it possible to differentiate between veterinary drug applications that do or do not permit compliance with the ADI. 

The committee recommends the inclusion of a detailed and accurate exposure analysis for a subset of the biomonitored population in large-scale biomonitoring studies that includes analyses of environmental media in the residence and uses a survey instrument to obtain information on diet, consumer product use, occupational exposures, and other factors relevant to the chemical exposure pathways that are being examined. The exposure assessment can be patterned on protocols used in other exposure analyses, such as the National Human Exposure Assessment Survey (NHEXAS), the Minnesota Children s Pesticide Exposure Study, and Children s Total Exposure to Pesticides and Other Persistent Organic Pollutants. 

Carrington, C.D., and M.P. Bolger. 2002. An exposure assessment for methylmercury from seafood for consumers in the United States. Risk Anal. 22(4) 689-99. 

The second part of any risk assessment requires an estimate of consumer exposure to the migrating substance. This depends on a number of factors ... 

At the present time, most US pesticide tolerances were established prior to the passage of FQPA. In assessing consumer risk from exposure to pesticides, the EPA first estimates consumer exposure. The maximum legal exposure to the pesticide is usually first calculated by assuming that... 

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