Industrial exposure persistent toxic chemical chemicals

The chlorinated chemicals assessed do not have the same risk profile. For the more volatile chemicals the safety margins between the actual exposure and the level at which no effect on the environment would be expected is quite high. For more persistent chemicals there is a need to look to the environmental compartment where they can be accumulated (mainly in sediments and biota). For some of these chemicals the safety margin is quite low and in worst-case situations serious effects may occur. For the very persistent, bioaccumulative and toxic chemicals (like dioxins, PCBs and DDT), acceptable environmental concentrations are so low and difficult to control that the industry is committed to reducing as far as possible releases to the environment through application of Best Available Techniques (BAT), mainly with respect to dioxins. For other chemicals (PCBs, DDT), production has already been halted for some years. 

Abstract Phthalates are chemicals that have been used for over 80 years in large quantities due to their wide range of applications, mainly in the plastic industry. For many years, these compounds were not considered dangerous for humans due to their low toxicity shown in the preliminary studies and their low persistence. However, research conducted in recent years has evidenced their activity as endocrine disrupters, and they are now considered as emerging contaminants and included in the priority list of dangerous substances in the legislation of many countries. This chapter provides an overview on the properties, major uses, emission sources, environmental and human levels, current legislation, behavior and fate of phthalates, and their metabolites, with special emphasis on their toxicity and human exposure. 

REACH introduces the concept of adequate control in EU chemical law. Traditionally, the term adequate control has been used to refer to good practice in the workplace. REACH now redefines adequate control in the form of risk management measures detailed in an exposure scenario necessary for the control of hazardous properties. Through a set of systematic procedures, risk management measures must be selected to reduce exposure below which adverse effects to human health or the environment are likely to occur (i.e., a DNEL, DMEL or PNEC). There is debate as to whether a concept of a safe level of exposure reduction, similar to adequate control, can apply to non-threshold carcinogens and mutagens, endocrine disruptors, persistent, bioaccumulative and toxic (PBT) or VPVB substances (e.g., [270]). Industry may need to demonstrate that exposure to these substances is always avoided or minimised, as specified in Annex I of the REACH Regulation. 

Authorisation. The use of chemicals considered to be of very high concern would be subject to authorisation. The aim is for such chemicals to be phased out and substituted, unless industry can show that the use presents negligible risk or that it is acceptable, taking into account its socioeconomic benefits, the lack of safer chemicals and measures to minimise exposure. Chemicals of very high concern are likely to include carcinogens, mutagens or reprotoxic substances (CMRs), particularly persistent, bioaccumulative and toxic substances. 

The International Program for Chemical Safety (IPCS) of the World Health Organization has made several recormnendations. Polybrominated diphenyls production (France) and use should be limited because of the concern over high persistency, bioaccumulation and potential adverse effects at low levels. There is limited toxicity data on deca- and octabromodiphenyls. Commercial use should cease unless safety is demonstrated. For the polybrominated diphenyl oxides, a Task Group felt that polybrominated dibenzofurans, and to a lesser extent the dioxins, may be formed. For decabromodiphenyl oxide, appropriate industrial hygiene measures need to be taken and environmental exposure minimized by emission control. Controlled incineration procedures should be instituted. For octabromodiphenyl oxide, the hexa- and lower isomers should be minimized. There is considerable concern over persistence in the environment and the accumulation in organisms, especially, for pentabromodiphenyl oxide. 

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