dichloromethane; methylene chloride

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.31 mg/L

Assessment factor:

20

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.27 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.031 mg/L

Assessment factor:

200

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

0.027 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

26 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

2.57 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.26 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.33 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

For DCM short term L(E)C50 values from validated sources are reported for fish and invertebrates. For fresh water fish the lowest LC50 value from validated data is 97 mg/l (Fundulus heteroclitus), for invertebrates the lowest LC50 value is 27 mg/l (Daphnia magna).

In addition to short-term toxicity data, long- term toxicity data are reported for fish and algae, but only a modeled 21d NOEC range for daphnids between 6.2 -13.3 mg/L. For fish a 28-day NOEC value of 83 mg/l is reported for Pimephales promelas. For fresh water algae an 8-day Toxicity Threshold value, equivalent to an EC3 value, of 550 mg/l is reported, which can be considered a long-term NOEC value. These chronic data have been used to derive the PNECs, but as a modeled value was included, an additional AF of 2 was used on the lowest chronic value available (6.2 mg/L for daphnids).

The toxicity of dichloromethane to activated sludge was evaluated by a simple respirometric procedure set up on the basis of OECD Method 209. The exposure duration, however, was only 40 minutes. Several other studies were available; however these studies were either less relevant for toxicity towards STP-organisms or the toxicity values were indecisive (greater than values). The lowest threshold level (40-min EC50) was 2590 mg/l in aerobic domestic sludge.

No reliable data is available for sediment or soil organisms. Various studies were performed with Eisenia fetida (earthworm) and various higher plants. However, they were either not relevant for the endpoint or the original study could not be found and the available information was not sufficient.

Conclusion on classification

DCM has a harmonized classification (Index no. 602 -004 -00 -3). DCM does not have a harmonized classificication for environment (neither acute nor chronic).

Three acute endpoints for three different trophic levels are available. The lowest EC50 is found for Daphnia magna and is 27 mg/L.

Results of validated structure activity relationships and expert judgment may be taken into account where appropriate with regard to classification and labelling of substances. Long-term study results are also available:

a 28-d NOEC of 83 mg/L for Pimephales promelas; EC3 of 550 mg/L for the alga species Microcystis and a modeled value for daphnids, a 21d NOEC of 6.2 -13.3 mg/L.

The substance is readily biodegradability and has a low log Kow of 1.25.

Acute endpoints are all > 1 mg/L, therefore under Regulation (EU) No 286/2011 (2nd ATP to CLP) DCM does not need to be classified acute aquatic hazardous.

The substance is readily biodegradable and all chronic endpoints are > 1.0 mg/L. Therefore, DCM does not need to be classified chronic aquatic hazardous.

Proposal for self-classification: Not classified for environment