Risk assessment for human health

A biocidal product can only be placed on the market if the risk assessment confirms that, in foreseeable application including a realistic worst-case scenario, the product presents no unacceptable risk to humans exposed to the substances of the product directly or indirectly through the environment. 

The assessment should cover the proposed normal use of the product and treated material if applicable. In addition, the realistic worst-case scenarios should include reasonably foreseeable misuse, such as ingestion by a child, but not accidents or attempted suicides). It should also include relevant production and disposal issues for both the product and treated material. Therefore, the risk assessment should cover the entire the lifecycle of the product. 

In the EU, risk assessment methodologies for human health have been described in the Technical Guidance Documents (TGDs) first published in 1996 and adapted in 2003. Initially these guidance documents were produced to support Commission Directive 93/67/EEC on risk assessment for new notified substances and 

Melting point, boiling point Relative density Vapour pressure 

Appearance including physical state, colour and odour 

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WHO/IPCS. 2001a. Neurotoxicity risk assessment for human health Principles and approaches. Environmental Health Criteria 223. Geneva WHO. http //www.inchem.org/documents/ehc/ehc/ehc223.htm... 

Mycotoxins, selected ochratoxins, trichothecenes, ergot (No. 105,1990) Nephrotoxicity associated with exposure to chemicals, principles and methods for the assessment of (No. 119,1991) Neurotoxicity associated with exposure to chemicals, principles and methods for the assessment of (No. 60,1986) Neurotoxicity risk assessment for human health, principles and approaches (No. 223,2001)... 

Harry, J., B. Kulig, M. Lotti, H. Tilson, and G. Winneke, eds. Neurotoxicity Risk Assessment for Human Health. Environmental Health Criteria 223. Geneva World Health Organization, 2001. 

The safe management of chemicals in the EU is based on the stepwise approach illustrated in Figure 23-3. In April 1996 a Technical Guidance Document was pub-lished to provide guidance on the risk assessment of both notified substances (as required under Commission Directive 93/67/EEC) and existing substances (under EC Regulation No. 1488/94) This guidance document deals with the risk assessment for human health and the environment, and covers also the use of (quantitative) structure-activity relationships. Of particular importance for the outcome of the risk assessment are the emission scenario documents, especially with respect to the default values, which will he applied if experimental data are not available. 

P. W. Harvey and D. J. Everett, Regulation of endocrine-disrupting chemicals critical overview and deficiencies in toxicology and risk assessment for human health. Best Pract. Res. Clin. Endocrinol. Metab., 2006, 20, 145-165. 

Therefore, risk assessment for human health is limited by (i) the scarcity of analytical data and poor predictive power of cadmium distribution in the body in relation to health outcome, (ii) the lack of information about chronic effects of cadmium accumulating over decades in tissues, and (iii) the lack of suitable biomarkers other than for irreversible kidney damage. Thus, the epidemiological studies linking health effects and cadmium exposure suffer from a relative lack of consensus knowledge about the modes of action of cadmium in multi-cellular... 

There is a continuing interest in the development of biomarker assays for use in environmental risk assessment. As discussed elsewhere (Section 16.6), there are both scientific and ethical reasons for seeking to introduce in vitro assays into protocols for the regulatory testing of chemicals. Animal welfare organizations would like to see the replacement of toxicity tests by more animal-friendly alternatives for all types of risk assessment—whether for environmental risks or for human health. 

K. Asante-Duah Public Health Risk Assessment for Human Exposure to Chemicals. 

Kimmel CA (1990) Quantitative approaches to human risk assessment for noncancer health effects. Neurotoxicology, 11 189-198. 

In the dose-response assessment to determine a dosage that is risk-free for human health, the JFCFA has never used mathematical models to extrapolate risks at low dose and determine a virtually safe dose, on the grounds that the lack of validation would produce very different results. However, the IFCFA could usefully address this matter in its deliberations. When progress in this area permits selection from various validated models, this exercise should no longer be solely associated with risk assessment but will also incorporate an element of risk management. 

USEPA (2006). Triazine Cumulative Risk Assessment. HED Human Health Risk Assessment in Support of the Reregistration Eligibility Decisions for Atrazine, Simazine and Propazine. March. 

Ecological risk assessments, like human health risk assessments, are based on scientific data that are frequently difficult and complex, conflicting or ambiguous, or incomplete. Analyses of such data for risk assessment purposes depend on professional judgment based on scientific expertise. Professional judgment is necessary to ... 

Asante-Duah, K. (2002a). Design of public health risk managment programs. In Public Health Risk Assessment for Human Exposures to Chemicals, Kluwer Academic Publishers, London, pp. 237-256. 

The rapporteur then produces a draft risk assessment regarding human health and the environment, and proposes any necessary risk limitation strategies. Such measures are for adoption at EC level using existing provisions (such as classification and labelling, occupational exposure limits or very occasionally, by restrictions on marketing and use under the provisions of the marketing and use directive , ie. Council Directive 76/769/EEC [29] as amended), and can be undertaken only after a risk/benefit evaluation on the chemical. 

The cumulative dose-effect curve is used extensively to characterize chemical toxicity. It provides a foundation for aU forms of chanical risk assessment including human health risk assessment and ecological risk assessment. Because this relationship will be encountered again and again when evalnating risk, several important features of the cumulative dose-effect curve are worth anphasizing ... 

Asante-Duah, K. (2002). Public health risk assessment for human exposure to chemicals. Kluwer Academic Press, Boston. 

EPA (1989) indicated that actual doses could not be verified, considered the study inappropriate for human health risk assessment, and rejected it for use in the development of a hazard advisory. No mortality occurred and no toxic effects were noted in beagle dogs (4 per sex per dose group) that received diisopropyl methylphosphonate in the diet (0, 4, 38, or 75 mg/kg/day) for 13 weeks (Hart 1980). 

EPA (1989) also indicates that analysis of the diisopropyl methylphosphonate used in this study determined that it was only 65% pure. Therefore, results from the Army (1978) study are considered inappropriate for human health risk assessment. No deaths of adult rats were recorded in a three-generation study of reproductive effects in rats receiving diisopropyl methylphosphonate in the diet at 0, 30, or 300 mg/kg/day (Hart 1980). 

No differences were noted in the litter sizes among those treated and the controls. No differences were noted in the number of stillborn pups or in pup weights. The study authors concluded that there was no evidence of adverse diisopropyl methylphosphonate-induced reproductive effects. However, as discussed in Section 2.2.2.1, there is some confusion regarding the actual doses to which the animals were exposed in the Hardisty et al. (1977) study. Therefore, results from this study are considered inappropriate for human health risk assessment. 

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