VERY PERSISTANT BIOACCUMULATIVE

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. 

PBTs (in addition to those listed by governmental organizations) vPvBs (very persistent, very bioaccumulating) substances... 

The Danish List of Undesirable Substances is a list of chemicals of concern that the government believes should be avoided to the extent feasible in commerce. Using a systematic analysis, substances are selected automatically if they meet some clear and defined criteria, for example, problematic classifications, because they are imder suspicion for being PBT/vPvB (Persistent, Bioaccumulative, Toxic/very Persistent, very Bio accumulative) or endocrine-disrupting. 

Persistent, Bioaccumulative and Toxic and Very Persistent and Very Bioaccumulative Substances... 

Authorisation will also be required for persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances. The PBT and vPvB criteria are defined in Annex XII of the Regulation (Table 7). There are subtle differences in the... 

NOEC No-observed effect concentration vPvB Very persistent and very bioaccumulative... 

All PCDD/F isomers are solids with high melting points, but low vapor pressure and low solubihty in water. The high octanol-water coefficients are an indication of the observed bioaccumulative behavior in plants and animals for these compounds. Detailed environmentally important physicochemical properties can be found in the literature. All higher chlorinated compounds are very persistent in the environment with half-lives of 5-10 years photolysis with sunlight is the only degradation process in the environment. 

As long as chemical regulation is based on this risk-based philosophy, human and environmental exposure to dangerous chemicals - substances of very high concern - will continue. The disperse and dilute model does not work for persistent bioaccumulative chemicals because Nature quite simply collects and concentrates these materials overtime. 

This is also accounted for in the planned EU chemicals regulation. Substances that are very persistent and very bioaccumulative can be introduced subject to authorisation, even when there are no scientifically based indications of (eco)toxicological effects. 

These relationships allow for screening and ranking of toxicity so that the least toxic option may be used if deemed appropriate. They are applied in many jurisdictions for regulatory use in the prediction of ecological effects (and fate) of chemicals when there are no actual toxicity data and decisions need to be made about their use [99]. QSARs have been developed, for example, to predict which chemicals may exhibit persistence, bioaccumulation, and toxicity (PBT) properties, or be very persistent and very bioaccumulative (vPvB) [99]. These methods have been applied to the prediction of chemicals that fall under the European REACH initiative and also high production volume (HPV) chemicals [99]. Currently available QSARs for predicting a compound s fall into two general classes those that have been developed for a nonspecific mode of action, and those that have been developed for specific types or classes of chemicals [99]. 

If the pharmaceutical fulfills the criteria for PBT (Persistent, Bioaccumulative and Toxic) and/or vPvB (very Persistent and very Bioaccumulative), the following phrase is added The substance fulfills the EU criteria for PBT/vPvB classification. 

Diddrin [60-57-1] or l,2,3,4,10,10-hexachloro-l,4,4tf,5,8,8tf-hexahydro-6,7-epoxy-l,4- dvx< 5,8-dimethanonaphthalene (34) (mp 176°C, vp 0.4 mPa at 20°C) is formed from aldrin by epoxidation with peracetic or perbenzoic acids. It is soluble in water to 27 //g/L. Aldrin and dieldrin have had extensive use as soil insecticides and for seed treatments. Dieldrin, which is very persistent, has had wide use to control migratory locusts, as a residual spray to control the Anopheles vectors of malaria, and to control tsetse flies. Because of environmental persistence and propensity for bioaccumulation, registrations in the United States were canceled in 1974. 

Predictions for very persistent and very bioaccumulative (VPVB) substances using physico-chemical parameters and the EUSES model often result in false-positive values [136]. 

A Chemical Safety Report that documents chemical risk assessments must be prepared for substances that a company manufactures or imports at >10 tonnes per year. If a substance is identified as dangerous or very persistent and very bioaccumulative (VPVB), a set of exposure scenarios detailing the relevant risk management measures necessary to reduce exposures must be attached as an Annex to existing Safety Data Sheets. 

Vereinte Dienstleistungsgewerkschaft Very persistent and very bioaccumulative Dutch Ministry of Housing, Spatial Planning and the Environment... 

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. 

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