187
Focusing on Impact Chemicals
PBT SUBSTANCES
A substance that fulfills all three of the criteria of the following sections is a
PBT substance.
Persistent chemicals are those that have
1. A half-life in marine water longer than 60 days,
2. A half-life in fresh- or estuarine water longer than 40 days,
3. A half-life in marine sediment longer than 180 days,
4. A half-life in fresh- or estuarine water sediment longer than 120 days, or
5. A half-life in soil longer than 120 days
Bioaccumulative chemicals have a bioconcentration factor (BCF) higher than
2,000 in aquatic species. Data from freshwater as well as marine water species can
be used.
Toxic chemicals are those that have
1. The long-term no-observed effect concentration (NOEC) for marine or
freshwater organisms is less than 0.01 mg/L,
2. The substance is classified as carcinogenic (Category 1 or 2), mutagenic
(Category 1 or 2), or toxic for reproduction (Category 1, 2, or 3), or
3. There is other evidence of chronic toxicity
VERY PERSISTENT, BIOACCUMULATIVE, AND TOXIC SUBSTANCES
The very persistent, bioaccumulative, and toxic (VPBT) chemicals are those that have
1. A half-life in marine, fresh-, or estuarine water longer than 60 days or
2. A half-life in marine, fresh-, or estuarine water sediment longer than
180 days or in soil longer than 180 days
Bioaccumulative chemicals have a BCF higher than 5,000 in aquatic species.
RESTRICTION
The REACH program has proposed to ban certain uses of chemicals. Some of these
chemicals and uses are shown in Table 11.9.