Methyl phenylacetate

PBT assessment

PBT assessment: overall result

Reference

Name:

methyl phenylacetate

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

methyl phenylacetate

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of Methyl phenylacetate for effects in the environment:

 

The chemical Methyl phenylacetate (CAS no. 101-41-7) is used to make perfumes. It is also used as a flavouring agent.Also used to formulate industrial and consumer washing-cleaning products, polishes-waxes, consumer air care products, biocidal products, cosmetics, and personal care products. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled forMethyl phenylacetate.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 does not fulfil the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

In an experimental key study from study report (2015), 28-days Manometric respirometry test following the OECD guideline 301F to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20± 1°C. Mixture of domestic waste water, surface soil and soil samples was used as a test inoculum for the study. This inoculum was collected and were mixed to get diluted suspension. The inoculum was kept aerobic until being used for experiment by supplying organic and inorganic sources required by micro flora to sustain at controlled laboratory conditions.  This gave the bacterial count as 107to 108 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. OECD mineral medium was used for the study. The test system included control, test item and reference item. The concentration of test and reference item ( Sodium Benzoate) chosen for both the study was 100 mg/L, while that of inoculum was 100 mg/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 % degradation of procedure control (reference substance) was also calculated using BOD & ThOD and was determined to be 227.4%. The DO depletion (mg O2/l) in control on 28th day is 19.1 mg O2/l which full fills the control validity criteria (i.e., The DO depletion of the inoculum blank is normally 20-30 mg O2/l and should not be greater than 60 mg/l in 28 days). Degradation of Sodium acetate exceeds 168.29% after 7 days and 212.76 % after 14 days. The activity of the inoculum is thus verified and the test is considered as valid. The BOD28 value of test chemical was observed to be 1.469 mgO2/mg. ThOD was calculated as 2.237 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was determined to be 65.66%.Based on the results, the test item, under the test conditions, was considered to be readily biodegradable at 20 ± 1°C over a period of 28 days.

 

Another biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical (HSDB and PubChem, 2017). The study was performed according to OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test) under aerobic conditions. Activated sludge was used as a test inoculums for the study. Test substance undergoes 75% degradation by BOD parameter in 28 days and 10-day window criteria is fulfilled during the study. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

Thus, based on the available information, it indicates that chemical Methyl phenylacetate can be considered to be readily biodegradable in water and thus likely to be not persistent (not 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 69.4%). In soil,Methyl phenylacetatewas expected to have moderate mobility based upon a Log KOC value ranging from 1.86 to 2.4, respectively. The half-life in soil (30 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, 26.5% 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 (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low.

 

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 1% i.e. reported as 0.175% when estimated by EPI Suite version 4.1).

 

Hence it has been concluded that Methyl phenylacetate is not persistent in nature.

 

 

Bioaccumulation assessment

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

 

The BCF value from authoritative & modelling databases was determined to be 7.48 to 18.4, respectivelyand the octanol water partition coefficient of the test chemical was determined to be 1.82 to 2.09, respectively, 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 does not fulfil 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 and algae for the substanceMethyl phenylacetateindicates the LC50/EC50 value to be in the range > 25 mg/l to 220.89 mg/L, respectively and on the basis ofthe various experimental studies of shortterm eco-toxicity data for aq. invertebratesof the structurally and functionally similar read across chemical (including the biodegradability of read across chemical) and applying the weight of evidence approach, the LC50/EC50 value was determined to be ranges from 100 to 230 mg/l, respectively. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations. Since the test chemical is readily biodegradable in nature, chemical Methyl phenylacetate is likely to be not hazardous to aquatic organisms at environmentally relevant concentrations and thus can be considered to be ‘Not classified’ as per the CLP regulation.

 

There are no available long-term toxicity evaluations forchemicalMethyl phenylacetate. 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 does not fulfil the P, B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.