UK Chemicals Stakeholder Forum (CSF)
General criteria for concern of the UK Chemicals Stakeholder Forum
The Forum’s assessment of substances to identify those of concern is based on the following properties: Persistence, Bioaccumulation and Toxicity. Substances that meet either the criteria to be classed as Persistent, Bioaccumulative and Toxic (PBT) or the criteria to be classed as very Persistent and very Bioaccumulative (vPvB) are considered of concern.
These criteria are defined below, see the detailed definitions webpage for further information.
PBT
P (persistent)
Chemicals that are persistent are those which either take a long time to decay once they are released into the environment, or do not decay at all. The Forum classes a substance as persistent if it does not decay to half of its original quantity within two months (if in water) or six months (if in soil or sediment).
B (bioaccumulative)
Chemicals that are bioaccumulative have a strong tendency to remain in the fatty tissue of organisms which they enter. This property is more frequently assessed with a proxi test to determine its attraction to fatty tissue over water. A substance is classed as bioaccumulative if it favours fatty tissue to water in a ratio (quantity-wise) of 10,000 to 1 or more.
T (toxic)
Chemicals that are toxic cause direct damage to organisms that are exposed to them. The Forum's criteria for toxicity generally follow those outlined in EU Directive 67/548/EEC. In addition to the directive, a substance is classed as being of concern if it is fatal to at least 50% of waterborne organisms in a given sample, where the concentration of the substance is 0.1mg per litre or less.
vPvB
vP (very persistent)
The Forum classes a substance as persistent if it does not decay to half of its original quantity within two months (if in water) or six months (if in soil or sediment). This is the same threshold as used for P under the PBT criteria – if it is met and the substance meets the vB criteria, then it is considered vPvB.
vB (very bioaccumulative)
A substance is classed as very bioaccumulative if it favours fatty tissue to water in a ratio (quantity-wise) of 100,000 to 1 or more.
Safety Net Procedure
The Forum also has a safety net procedure for chemicals that do not meet the PBT or vPvB criteria but where there are reasons to believe that the chemicals raise equivalent concerns.
Page last modified:
23 November 2006
Page published: 4 December 2002