Under Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances and Commission Directive 93/67/EEC on Risk Assessment for new notified substances, now both replaced by the REACH Regulation (EC) 1907/2006, "an interim strategy for management of persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances" had been agreed in June 2001.

This interim PBT strategy had the following steps:

1. Developing PBT and vPvB criteria and testing strategies;
2. Identifying potential PBT or vPvB substances using screening data and QSARs for substances for which relevant data is missing;
3. Verifying PBT or vPvB properties by additional testing using the existing EU chemicals legislation on existing and new substances;
4. Qualitatively evaluating the sources, major emissions and pathways to the environment to establish the most appropriate and effective measures to minimise exposure to humans and the environment;
5. Implementing the necessary measures into Community legislation.

To implement step ‘3', a "TC NES sub-group on identification of PBT and vPvB substances" was established under the TC NES (Technical Committee for New and Existing substances) with the task of performing a case-by-case evaluation of potential PBT/vPvB substances and to give recommendations on the most appropriate follow-up actions.

As for ECHA's PBT Expert Group (EG), the TC NES sub-group consisted of representatives of Member States and of the European Commission. Stakeholder organisations were also involved in the PBT assessment activities by providing their expertise and new data to the TC NES sub-group. The Expert Group was managed by the former European Chemicals Bureau in the European Commission's Joint Research Centre (JRC).

The criteria for identifying PBT/vPvB substances used by the TC NES sub-group were those laid down in the Technical Guidance Document on Risk Assessment in support of the chemicals legislation preceding REACH.

It should be noted that, for a number of substances, the conclusion to be a PBT or a vPvB was based solely on screening criteria for PBT/vPvB assessment. The latter approach does not follow the current practice under the REACH Regulation, where further information would need to be generated to conclude on the PBT/vPvB properties of the substance by assessing against the definitive PBT or vPvB criteria. In addition, due to confidentiality issues, the work carried out by the TC NES sub-group on new notified substances (covered by Commission Directive 93/67/EEC) is not disseminated on ECHA's website.