1,4-dichlorobenzene risk assessment

This voluntary risk assessment programme started in 1995 and concerned a list of 25 chemicals dichloromethane, chloroform, tetrachloromethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, vinyl chloride, trichloroethene, tetra-chloroethene, hexachlorobutadiene, monochlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, tetrachlorobenzene, hexachlorobenzene, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, pentachlorophenol, hexachloro-cyclohexane, dioxins, PCB, DDT, and elemental mercury. 

If PBPK models for 1,4-dichlorobenzene exist, the overall results and individual models are discussed in this section in terms of their use in risk assessment, tissue dosimetry, and dose, route, and species extrapolations. 

Reliable monitoring data for the levels of 1,4-dichlorobenzene in contaminated media at hazardous waste sites are needed so that the information obtained on levels of 1,4-dichlorobenzene in the environment can be used in combination with the known body burdens of 1,4-dichlorobenzene to assess the potential risk of adverse health effects in populations living in the vicinity of hazardous waste sites. 

Battelle and. Crump KS, and Co., Inc. 1986. Quantitative risk assessment for 1,4-dichlorobenzene prepared for Exposure Evaluation Division. U.S. Environmental Protection Agency, Office of Toxic Substances, under Contract No. 68-02-4246. 

Table 9.6 lists statements of critical effect or main adverse effect of p-dichlorobenzene that the OEL is supposed to protect against together with the OELs and year of risk assessment. The large variability of the OELs to some degree... 

As this example with p-dichlorobenzene shows the different levels of OELs are connected to differing scientific opinions on the harmful effects of the substance. The selection of what data to review obviously is important for the outcome of the risk assessment. It can also be concluded to not only being dependent on the time-related availability of the data. The potential for a selection bias of what literature to review in risk assessments has been shown by Ruden for the risk assessments concerning the carcinogenic properties of trichloroethylene (Ruden 2001). Although a case-study of acryl amide (Ruden 2004) shows that a selection bias by no means is an inevitable consequence. Another aspect of which the conclusions from a risk... 

Another interesting aspect of differences in the documentation is the use of uncertainty or safety factors. These are commonly used in food safety and environmental risk assessment, but customarily not used when deriving occupational exposure limits. A study of the margins of safety used in OELs comprising 14 substances and 45 OELs and the documentation for these only found four instances where explicit safety or uncertainty factors had been used (Schenk, 2010). Two of these instances concerned p-dichlorobenzene making this substance rather unique. The documentations in question are from the EU and France. The magnitude of the uncertainty factors differs between them the EU applied a factor of 10 and France a factor of hundred. But this is again explainable by the different severity of the concluded critical effects (Table 9.6). 

Risk Assessment 1-4 Dichlorobenzene, Draft Report March, National Institute of Research and Security, 1999. 

Safety Commission Consumer Products Copper (Cu) Corrosives Corticosteroids Cosmetics and Personal Care Products Cotinine Coumarins Creosote Cresols Cromolyn Cumene Cumulative Risk Assessment Cyanamide Cyanide Cyanogen Chloride Cyclodienes Cyclohexamide Cyclohexane Cyclohexene Cyclophosphamide Cyclosporine Cyfluthrin Cypermethrin Cysteine Cytochrome P-450 "2,4-D (2,4-Dichlorophenoxy Acetic Acid)" Limonene Dalapon DDT/DDE/DDD Decane DEBT (Diethyltoluamide) DEE Deferoxamine DEHP (Di-Ethyl Hexyl Phthalate) Delaney Clause Deltamethrin Deodorants Detergent Developmental Toxicology Dextromethorphan Diazepam Diazinon Diazoxide Dibenzofuran " Dib enz [a, h] anthracene" Dibromochloropropane Dibutyl phthalate Dicamba Dichlone Dichlorobenzene Dichloroethanes "Dichloroethylene, 1,1-"... 

European Commission. 2004. European Union Risk Assessment Report -1,4-Dichlorobenzene. CAS No 106-46-7. EINECS No 203-400-5. Risk Assessment. Available at http //echa.europa.eu/documents/10162/fb7bf6b4-7831-4c3b-87b3-5acd493ce597 (accessed December 8,2013). 

European Commission. 2008. Commission Communication on the Results of the Risk Evaluation and Risk Reduction Strategies for the Substances Piperazine Cyclohexane Methylenediphenyl diisocyanate But-2yne-l,4-diol Methyloxirane Aniline 2-Ethylhexylacrylate 1,4-Dichlorobenzene 3,5-dinitro-2,6-dimethyl-4-tert-butylace-tophenone Di-(2ethylhexyl)phthalate Phenol 5-tert-butyl-2,4,6-trinitro-m-xylene. (2008/C 34/01) Available at http //esis.jrc.ec.europa.eu/doc/risk assess-ment/OJ RECOMMENDATION/ojrecl06467.pdf (accessed December 8,2013. 

The proposed restriction on 1,4-dichlorobenzene (1,4-DCB) illustrates the process. Concerns over the potential toxicity of this compound first surfaced under the Dangerous Substances Directive. The European Commission subsequently assessed the risks from exposure to 1,4-EXZB under the Existing Substances Regulation, beginning in the mid-1990s. 

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