Triclocarban

PBT assessment

PBT assessment: overall result

Reference

Name:

Triclocarbon

Type of composition:

boundary composition of the substance

State / form:

solid: bulk

Reference substance:

Triclocarbon

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)ureafor effects in the environment:

 

The chemical 1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)urea (CAS no. 101-20-2) is used as an bacteriostatic and antiseptic in soaps and cleaning products. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)urea.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

Although 1 study from authoritative database indicate that the chemical 1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)urea is not readily biodegradable, but based on the other various experimental study results from peer reviewed journal of biodegradation studies for the test chemical1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)urea(CAS no. 101-20-2), it indicates thatchemical1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)ureacan be considered to be readily biodegradable in water and thus likely to be not persistent (not P) in nature.

 

Environmental fate

In soil,3-Nitrobenzoic acidwas expected to have negligible to slow mobility based upon a Log KOC value ranging from 3.68 to 5.32, respectively. The half-life in soil (173 to 231 days from authoritative database) indicates that the chemical is persistent in soil and the exposure risk to soil dwelling animals is moderate to high. 

 

If released in to the environment, 8.53% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (60 days estimated by EPI suite) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high.

 

Moreover, its persistent characteristic is only observed in the sediment compartment but Fugacity modelling shows that sediment is not an important environmental fate (less than 3% i.e. reported as 2.52% when estimated by EPI Suite version 4.1).

 

Hence, based on the half-life value of test chemical 1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)urea in soil, it has been concluded that 1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)ureais 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:

 

The estimated BCF value from authoritative databases was determined to beranges from 61 to 887 dimensionless, respectively and the octanol water partition coefficient of the test chemical was determined to be 3.633, 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 not classified for carcinogenicity, mutagenicity and reprotoxicity, Further, there is no evidence of chronic toxicity, as identified by the classifications STOT (repeated exposure), category 1(oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume) or category 2 (oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume).

 

Aquatic organisms

All of the available short-term eco-toxicity data for fish, invertebrates and algae for the substance1-(3',4'-Dichlorophenyl)-3-(4'-chlorophenyl)ureaindicates the LC50/EC50 value to be in the range 0.0031 to 0.18 mg/L, respectively. Whereas on the basis ofthelong term eco-toxicity data for fish and aq. Invertebrates, the NOEC value was determined to be ranges from 0.0019 to 0.024 mg/l, respectively and EC50 value was determined to be > 0.001 mg/l. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations and can be considered to be classified in ‘Aquatic Acute Category 1’ and ‘Aquatic Chronic Category 1’ as per the CLP regulation.

 

By speculation, long-term NOEC for aquatic organisms were expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.

 

The chemical was therefore 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 criterion and has therefore not been classified as a PBT compound within Annex XIII.