Hazard identification test strategies

The main subject of this chapter is the identification of hazardous chemicals, materials, mixtures, and reaction masses. The chapter deals with undesired decompositions and hazardous reactions. A basic knowledge of the chemistry involved, and, in particular, with the thermodynamics and kinetics, is required. Furthermore, it is important to have a test strategy to recognize and assess the hazards associated with the energetic materials, mixtures, and reaction masses. 

The capacity of a chemical to cause harm is what the hazard identification stage of risk assessment is intended to identify - the hazards of a chemical are the adverse effects [harm] which [it] has an inherent capacity to cause (Article 2 of Directive 93/67/EEC). The identification of adverse effects on the health of humans and wildlife relies heavily on tests on laboratory animals. I have already discussed some of the many uncertainties that result from the use of animal tests. A key question is whether there are viable alternatives. Before proposing an alternative testing strategy I first consider animal tests as scientific experiments and ask whether they are good experiments, given what we want to find out. 

Thybaud V, Aardema M, Clements J, et al. Strategy for genotoxicity testing Hazard identification and risk assessment in relation to in vitro testing. Mutat Res. 2007 627(l) 41-58. 

While the standard combined chronic/cancer bioassay is helpful in hazard identification, it contributes in a more limited extent to hazard charactraization (i.e., the likelihood of causing adverse effects in humans). However, with some modification in the context of evolving integrated and hierarchical test strategies for groups of chemicals or individual substances, carcinogenicity bioassays have potential to contribute considerably additionally in this context. For example, as discussed... 

In summary, a practical testing strategy for oculotoxicity which utilises the framework of existing guidelines but which equally retains the flexibility to extend the range of technical procedures to address specific oculotoxic effects is considered to offer the best approach to hazard identification in man. 

Basketter DA, Whittle E, Chamberlain M (1994) Identification of irritation and corrosion hazard in skin An alternative strategy to animal testing. Food and Chemical Toxicology 32 539-542... 

Another strategy for exposure assessment analysis is based on the measurable binding of pesticides or metabolites to specific ceU receptors. In the areas of hazard assessment and exposure assessment, in vitro studies to assess mechanistic processes of toxicity, have been developed. These studies utilise new and innovative technologies such as genomics, transcriptomics and proteomics which allows the identification of in vitro clusters of genes and proteins that can be induced or silenced by pesticides or metabolites. The key point in these cases is to vahdate in vitro studies with in vivo exposure assessment by testing if mechanistic responses found in vitro correlates with in vivo exposure doses. This type of integrated, mechanism-driven in vitro to in vivo approach relies extensively on the use of cell assays to develop new biomarkers. 

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