Ethyltriphenylfosfonium bromide

PBT assessment

PBT assessment: overall result

Reference

Name:

ethyltriphenylfosfonium bromide

Type of composition:

boundary composition of the substance

State / form:

solid: bulk

Reference substance:

ethyltriphenylfosfonium bromide

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of Ethyltriphenylfosfonium bromide for effects in the environment:

 

The chemical Ethyltriphenylfosfonium bromide (CAS no. 1530-32-1) is used as a wittig reagent.It isused as phase transfer catalyst in the production of epoxy resins and powder coatings.Also used as pharmaceutical intermediate in several synthetic processes. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled forEthyltriphenylfosfonium bromide. 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

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test chemical 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 test 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 thatchemicalEthyltriphenylfosfonium bromideis 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 sediment (i.e.estimated to 60.8%). The half-life in sediment (337.5 days estimated by EPI suite) indicates that the chemical is very persistent in sediment and the exposure risk to sediment dwelling animals is moderate to high.

 

If released in to the environment, 36.2% of the chemical will partition into soil according to the Mackay fugacity model level III in EPI suite version 4.1 (2018).In soil,Ethyltriphenylfosfonium bromidewas expected to have rapid mobility based upon a Log Koc value of1.255 ± 0.023 at 25°C as per OECD TG 121, respectively.However, the half-life (75 days estimated by EPI suite) indicates that the chemicalis not persistent in soil and the exposure risk to soil dwelling animals is moderate to low. 

 

Moreover, its persistent characteristic is also not observed in the water compartment according to the Mackay fugacity model level III in EPI suite version 4.1 (2018) with a half-life value of 37.5 days. This half-life value indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low. 

 

Although the half-life values indicate the chemical to be Very persistent (vP), since only predicted data is available for the substance, it has been concluded that Ethyltriphenylfosfonium bromide 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 3.162 L/Kg, respectively and theoctanol water partition coefficient of the test chemical was determined to be -0.69, 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 oral 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 as per OECD TG for the substance indicates the LC50/EC50 value to be in the range 3.125 to > 39.42 mg/L, respectively and on the basis ofthe availablelong term eco-toxicity data for fish and aq. invertebrates, the 21/28 d NOEC value was evaluated to be 0.156 mg/l and 0.163 mg/l, respectively. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations and hence, considered to be classified in ‘Aquatic Chronic Category 2’ 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 criterionbut does not fulfil the B criterion and has therefore not been classified as a PBT compound within Annex XIII.