Phthalates

3. Can DBP affect the environment?

3.1 What happens to DBP released to the environment?
3.2 When is DBP released?
3.3 What levels of DBP are expected near the sources?
3.4 What are the effects of DBP on the environment?
3.5 What are the risks of DBP to the environment?

DBP may be released into the environment, particularly water and air, during its production and subsequent life cycle stages, including disposal. More...

3.1 What happens to DBP released to the environment?

DBP does not readily break down in water. It does break down in the presence of air but breakdown is much slower in sediment, deep soil and groundwater.

In the atmosphere DBP is broken down by sunlight. Its half-life in the atmosphere is estimated at 1.8 days. Half-life is the time taken for half the amount initially present to disappear.

The results of a laboratory test indicate a high potential for bioaccumulation of DBP in animal tissues, strong binding to sewage sludge, soils and sediments and very low mobility in soil. Tests on certain freshwater organisms have shown high amounts of DBP metabolites (breakdown products) can be concentrated in the body (bioconcentration). More...

3.2 When is DBP released?

DBP can be released at different stages: production, distribution, processing, use, incineration and disposal. The expected releases during these stages have been taken into account in this assessment. More...

3.3 What levels of DBP are expected near the sources?

Predicted Environmental Concentrations (PECs) have been calculated for various environmental media located near sources of DBP.

At production, formulation and processing sites concentrations:

• in surface water range from 1 to 9 μg/l and up to 10 times higher in effluent from the sites.
• in sediment range from 0.1 to 1.2 mg/kg and levels in soil range up to 1.5 mg/kg.
• in aquatic organisms near to sources range from 2 to 8 μg/kg and in soil dwelling organisms range from below 0.1 up to 10 mg/kg.
• in air range from 0.02 to 2.4 μg/m³, with highest levels around PVC processing plants. More...

3.4 What are the effects of DBP on the environment?

In tests on fish and aquatic invertebrates there were no adverse effects at concentration up to 100 μg/l. The Predicted No Effect Concentration of 10 μg/l for the aquatic compartment was obtained by dividing this figure by 10.

There are no test data on sediment dwelling organisms, but a PNECsediment of 1.2 mg/kg wet weight could be estimated from the aquatic PNEC.

For microorganisms, a PNEC of 0.22 mg/l was obtained. This value is rather low since other tests show no effect of DBP on microorganisms at concentrations higher than the solubility of DBP. Further, DBP also seems to be readily biodegradable.

For the terrestrial compartment a Predicted No Effect Concentration of 2 mg/kg dry weight was derived using tests on maize.

Studies on the toxicity of DBP to plants showed a wide range of effects at airborne concentrations ranging from 1.2 µg/m³ to 1 000 µg/m³. It was therefore decided that further chronic exposure testing was needed to establish a more reliable Predicted No Effect Concentration for plants exposed via air. Tests with seven plant species led to a Predicted No Effect Concentration of 0.1 µg/m³ for plants in air.

This may mean that eventually a label “toxic to flora” would be applied to DBP.

For top predators, based on the lowest observed adverse effect level of 52 mg/kg body weight in laboratory mammals, an oral Predicted No Effect Concentration of 104 mg/kg in food can be estimated. More...

3.5 How can workers be exposed to DBP?

For the aquatic and terrestrial environments as well as in animals, the predicted environmental concentrations were all below the predicted no effect concentrations (PNEC). It is concluded that there is at present no need for further information and/or testing or for further risk reduction measures beyond those being applied already.

However, in the particular case of environmental releases of DBP when it used in construction work as a grouting agent, it is concluded that high levels may be reached in surface water. Therefore the environmental impact of these kinds of operations should be carefully assessed and monitored.

In the atmosphere, the Predicted Environmental Concentrations were all above the provisional Predicted No Effect Concentrations for plants. There was therefore a need for further testing for long-term effects in plants. This was done and the results published in an addendum to the Risk Assessment Report. As a result of these new tests it was concluded that there is a need for limiting the risks to plants, taking into account of risk reduction measures which are already being applied, at sites of PVC, adhesive or glass fibre production as well as for printing ink usage. More...