Reaction mass of carbon tetrachloride and chloroform and 1,2-dichloroethane

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.22 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.2 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.022 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

30 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

3.326 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.333 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:

0.551 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

0.222 mg/kg food

Assessment factor:

90

Additional information

All calculated PNEC values are based on reliable studies according to the respective OECD guidelines.

Environmental fate and pathways:

In the review of Mabey & Mill (1978), it is states that a half life of 7000 years for a concentration of 1 ppm and 7 years for a high concentration of 1000 ppm was calculated at standard temperature (298K) for carbon tetrachloride. Therefore, hydrolysis is not a degradation relevant process for carbon tetrachloride under environmental conditions.

One OECD 301C study has been perfomed on carbon tetrachloride or CTC (CAS n° 56-23-5) by MITI (Japan, 1992). No biodegradation reported in this ready biodegradability test, but test conditions are not suitable for this substance. The study is scored as klimish 3 because the test substance at 100 mg/L is likely to be toxic to microorganisms, as reported in studies of carbon tetrachloride toxicity to aerobic bacteria.

A QSAR prediction was performed on CTC with the model used is Biowin v4.10, plug-in from EPISUITE v4.1 from US EPA (K2). This model is recommended by the ECHA guidance document on information requirements and is well documented with regard to validation parameters according to OECD principles. Moreover, the substance is fully characterised for the applicability domain. The Biowin 3 result is "months" and the Biowin 5 probability is less than 0.5, therefore the prediction is not readily biodegradable.

In conclusion,CTC is considered as not readily biodegradable (MITI Japan study, 1992; QSAR Biowin).

The K_ocmeans from 7 determinations were 143.6±32.11 L/kg for the silt loam and 48.9±16.16 L/kg for the sandy loam, while the weighted mean K_ocvalue for both soils was calculated being 115.2 L/kg.

Carbon tetrachloride is considered as highly mobile according to McCall et al. (1980)(Koc<150 L/kg).

Aquatic toxicity:

Acute and chronic data of reliabilities 1 or 2 (Klimisch rating), based on international guidelines, are available for three trophic levels: Algae, Invertebrates and Fish.Among all data available, algea seems to be the most sensitive specie with a NOEC72h at 2.2 mg/L. Regarding others organisms, NOEC(21d) was determined to be 3.1 mg/ L for Daphnia magna (OECD 211) and NOEC (14d) of 2.5 mg/L for fish (OECD 204). Both studies are considerd sufficiently reliable as a factor 10 was found for all type of organisms between acute and chronic data.

Terrestrial toxicity:

In the absence of any ecotoxicological data for sediment-dwelling/soil organisms, the PNEC sediment/soil were calculated using the equilibrium partitioning method (EPM). Furthermore, no toxicity studies reporting the secondary poisoning effects on bird were available to derive the PNECoral. A valid two-generation reproduction toxicity study on mammalian (rats) was used with this aim in view.

Conclusion on classification

According to the Regulation (EC) No 1272/2008 (CLP), carbon tretrachloride is classified as Aquatic Chronic 3 and Ozone 1 and is typically present at concentrations >25% in the multiconstituent substance, Flux1. In conclusion, Flux1 is classified as Aquatic Chronic category 3 and Ozone 1.

Based on data available in this registration dossier, carbon tetrachloride is not readily biodegradable, has a log Kow value below 4.0, a BCF value lower than 500. The acute E(L)C50 values on aquatic organisms are comprised between 10 and 100 mg/L and the lowest chronic NOEC value (on daphnia) is comprised between 1 and 10 mg/L. Based on these conclusions and according to the Annex I of the Regulation (EC) No 1272/2008 (CLP), carbon tetrachloride should not be classified for environment. As a consequence, Flux1 should not be classified as Aquatic Chronic category 3 and Ozone 1.