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WELCOME to the Environmental Assessment Toolbox 

 The environmental assesment toolbox is an online step-by-step tool designed to help the user to predict if his chemical has any impact on the environment and to do a quick PBT screening based on a QSAR approach.

What are PBTs?

Persistent, bioaccumulative, and toxic(PBT) substances are compounds that possess all three of the following characteristics, making them particularly problematic pollutants:

Persistent: Some substances are very persistent in the environment, with lifetimes on the order of decades to centuries. The molecular structures of these compounds allow them to resist the natural fate processes in the atmosphere, waters, and biota that break down other pollutants. The persistence of a chemical depends on its kinetics or reactivity, as expressed by its rates of degradation.   

Bioaccumulative: Substances that concentrate in fatty tissue tend to build up to much higher concentrations in humans and other organisms. They are also more likely to transfer and accumulate up the food chain (see figure below).


Toxic: Substances cause or are suspected to cause adverse effects to humans and wildlife in ways that range from minor skin irritations to cancer. 

Specific criteria have been developed to identify substances that are Persistent, Bioaccumulative and Toxic (PBT) and very Persistent and very Bioaccumulative (vPvB) chemicals. These are mentioned in step 5.

Why you need to do PBT screening?

Mainly because:

1. Persistent, Bioaccumulative and Toxic (PBT), very Persistent and very Bioaccumulative (vPvB) and CMR substances present potential risks to human health and the environment and therefore  should be subject to authorisation under the new EU chemical strategy REACH. Furthermore REACH will treat compounds that are R50/R53 as potential PBTs until proven otherwise as they are considered as substances of very high concern.

2 To comply with REACH, the environmental toxicity and environmental fate properties, including chemical and biotic degradation of any substance manufactured/imported in quantity of 1 tonne/year must be determined. This is usually made on the basis of experimental data for acute aquatic toxicity, degradation, and log Kow (Octanol/ Water Partition Coefficient) or BCF (Bioconcentration Factor).  The cost for these tests is significant and is a cost most SMEs cannot afford.

As a result, using an inexpensive protocol, which makes it possible to screen for chemicals of environmental concern and PBT would be beneficial and this is what this tool is about!

How to do it?

Simply by following the steps described in the overview.



Last Updated ( Thursday, 07 August 2008 )
© 2017 REACH Regulation: Registration, Evaluation, Authorization and Restriction of Chemicals: REACH Legislation