2,2,2-trichloroethane-1,1-diol

Endpoint summary

Description of key information

Biodegradation in water: screening tests:

The test item 2, 2, 2 trichloroethane-1, 1-diol (CAS No. 302-17-0) undergoes 44.04%biodegradation after 28 days in the test condition. Thus, the test item can be considered as inherently biodegradable.

Biodegradation in water and sediment:

Estimated half life of test chemical in water was (37.5) days (900 h) and in sediment estimated to be (337.5) days (8100 h).

Biodegradation in soil:

Biodegradation half-life of test substance in soil was estimated to be (75) days (1800 hrs).

Additional information

Biodegradation in water: screening tests:

Experimental key and predicted supporting data for the test substance chloral hydarte is reviewed for biodegradation in water which is summarised as follows:

In experimental key study, 28-days Manometric respirometry test following the OECD guideline 301F to determine the ready biodegradability of the test item2, 2, 2 -trichloroethane-1, 1 -diol(CAS No. 302 -17 -0) was conducted. The test system included control, test item and reference item. The concentration of test and reference item (Sodium Benzoate) chosen for the study was 100 mg/L, while that of inoculum was 10ml/l. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % Degradation was calculated using the values of BOD and ThOD for test item and reference item.

The BOD₂₈value of 2,2,2 -trichloroethane-1, 1 -diol(CAS No. 302 -17 -0) was observed to be 0.085 mgO₂/mg. ThOD was calculatedas 0.193 mgO₂/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was found to be 44.04%.Based on the results, the test item, under the test conditions, was found to be inherently biodegradable at 20 ± 1°C over a period of 28 days.

Supporting above data, Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound  2,2,2-trichloroethane-1,1-diol (Chloral hydrate)(CAS no. 302 -17 -0) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 2,2,2-trichloroethane-1,1-diol (Chloral hydrate) is expected to be not readily biodegradable.

Thus based on the above data it can be observed that substance is likely to be inherently biodegradable or not readily biodegradable. However considering the experimental key value the substance chloral hydrate is concluded to be inherently biodegradable in water.

Biodegradation in water and sediment:

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test compound 2,2,2-trichloroethane-1,1-diol (Chloral hydrate)(CAS No.302 -17 -0). If released in to the environment, 45% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of chloral hydrate in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 days estimated by EPI suite) indicates that the chemical isnot persistent in waterand the exposure risk to aquatic animals ismoderate to lowwhereas the half-life period of chloral hydrate in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.0885%), indicates that chloral hydrate is not persistent in sediment.

Biodegradation in soil:

The half-life period of2,2,2-Trichloroethane-1,1-diol (Chloral hydrate)(CAS No.302 -17 -0) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2018). If released into the environment, 54.8% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of chloral hydrate in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of chloral hydrate, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.