Trichloroacetaldehyde

PBT assessment

PBT assessment: overall result

Reference

Name:

trichloroacetaldehyde

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

trichloroacetaldehyde

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of Trichloroacetaldehyde for effects in the environment:

 

The chemical Trichloroacetaldehyde (CAS no. 75-87-6) is used to make trichloroacetic acid, chloral hydrate, DDT, methoxychlor, DDVP and trichlorofon. Also used to induce swelling of starch granules and to spray and pour polyurethanes.The aim was to assess whether the PBT criterion within Annex XIII was fulfilled forTrichloroacetaldehyde. The PBT criterion was herein assessed based on experimental data in conjunction with standardized environmental fate models. Here follows a description of the PBT assessment.

 

Persistence assessment

The tested substance fulfils the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

In an experimental study from authoritative database, biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical Trichloroacetaldehyde (CAS no. 75-87-6). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l. The percentage degradation of test substance was determined to 8, 0 and 70% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation (8 and 0%), test chemical was considered to be not readily biodegradable in nature.

 

Estimation Programs Interface Suite was run to predict the biodegradation potential of theTrichloroacetaldehyde (CAS no. 75-87-6) 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 is expected to be not readily biodegradable.

 

Other experimental results of the read across substances also indicate that they are not readily biodegradable.

 

Based on the available information, it has been concluded thatchemicalTrichloroacetaldehydeis likely to be persistent (P) in nature.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 53.8%).In soil,Trichloroacetaldehydewas expected to have moderate to rapid mobility based upon a Log Koc ranging from-0.167 to 2.252, respectively.The half-life in sediment (120 days estimated by EPI suite) indicates that the chemical is not persistent in soil and the exposure risk to soil dwelling animals is moderate to low.

 

If released in to the environment, 46.1% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2018). The half-life (60 days estimated by EPI suite) indicates that the chemicalis persistent in water and the exposure risk to aquatic animals is moderate to high. 

 

Moreover, its persistent characteristic is also observed in the sediment compartment but Fugacity modelling shows that sediment is not an important environmental fate (less than 1% i.e reported as 0.0942% when estimated by EPI Suite version 4.1).

 

Hence, it has been concluded that chemical Trichloroacetaldehyde is likely to be persistent (P) in nature.

 

Bioaccumulation assessment

The tested substance does not fulfil the B criterion within Annex XIII based on the assessment that here follows:

 

Theestimated BCF value from authoritative database was determined to be in the range of 3.162 to 9.85, respectively and theoctanol water partition coefficient of the test chemical was determined to be in the range of 0.99 to 1.61, which is less than the threshold of 4.5. If this chemical is released into the aquatic environment, there should be a low risk for the chemical to bioaccumulate in fish and food chains.

 

Toxicity assessment

The tested substance fulfils the T criterion within Annex XIII based on the assessment that here follows:

 

Mammals

The tested chemical is regarded to be classified for repeated dose toxicity in ‘’STOT RE 2 category’’ by inhalation route.

Further, the tested chemical is regarded to be not classified for carcinogenicity, mutagenicity and reprotoxicity.

 

Aquatic organisms

All of the available short-term eco-toxicity data for fish, aquatic invertebrates and algae for the substanceTrichloroacetaldehyde(CAS no. 75-87-6) indicates the LC50/EC50 value to be in the range 186.31 to 646.83 mg/L, respectively. These value suggest that the substance is likely to be not hazardous to aquatic organisms at environmentally relevant concentrations and hence, considered to be ‘not classified’ as per the CLP regulation.

 

By speculation, long-term NOEC for aquatic organisms were not expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.

 

The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.

 

Conclusion

Based on critical, independent and collective evaluation of information summarized herein, the tested compound fulfils the P and T criterion but does not fulfil the B criterionand has therefore not been classified as a PBT compound within Annex XIII.