IOELV, BOELV, BGV, BLV (def.)

IOELV, BOELV, BGV, BLV

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Indicative OELs (IOELVs) are health-based limits conventionally established only for substances for which it is possible to establish a threshold or a no effect level considered to be protective of health. To establish OEL, a thorough assessment of the available scientific information is essential as a first step. This is undertaken by the European Commission's Scientific Committee for Occupational Exposure Limits (SCOEL). These limit values should be established or revised taking into account the availability of measurement techniques. Member States should keep workers' and employers' organisations informed of IOELVs set at a Community level. For any chemical for which an IOELV is established at a Community level, Member States should establish a national occupational exposure limit value, taking into account the Community limit value, determining its nature in accordance with national legislation and practice.

Binding OELs (BOELVs) may be drawn up at a Community level and, in addition to the factors considered when establishing IOELVs, socio-economic and technical feasibility factors should be taken into account and intend to provide a level of minimum protection for all workers in the Community. For any chemical agent for which a BOELV is established, Member States should establish a corresponding national binding occupational exposure limit value based on, but not exceeding the Community limit value.

Biological guidance values (BGVs): BGVs are exposure-related guidance values in that they represent the upper concentration of the chemical agent or one of its metabolites in any appropriate biological medium corresponding to a certain percentile (generally the 90th or 95th percentile) in a defined reference population. It is preferred to use a nonoccupationally exposed working population as defined reference population, but in practice this may not be possible. As such, the defined reference population may vary from task to task.

Biological limit values (BLVs): BLVs relate to a chemical agent's concentration in the respective biological medium (e.g. blood, urine, breath). Exposure concentrations equivalent to the BLV generally do not affect the health of the worker adversely, when they are attained regularly under workplace conditions (8 hours/day, 5 days/week)

Binding biological limit values (BBLVs) may be drawn up at a Community level on the basis of evaluation as described for IOELVs and on the availability of measurement techniques, and should reflect feasibility factors while maintaining the aim of ensuring the health of workers at work. For any chemical agent for which a binding biological limit value is established, Member States should establish a corresponding national binding biological limit value based on, but not exceeding, the Community limit value. The BBLV is established for lead and its ionic compounds.