N-acetylsulphanilyl chloride

PBT assessment

PBT assessment: overall result

Reference

Name:

N-acetylsulphanilyl chloride

Type of composition:

boundary composition of the substance

State / form:

solid: bulk

Reference substance:

N-acetylsulphanilyl chloride

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of N-acetylsulphanilyl chloridefor effects in the environment:

 

The chemical N-acetylsulphanilyl chloride (CAS no. 121-60-8) is used as an intermediate in the preparation of sulphanilamide and its derivatives. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled forN-acetylsulphanilyl chloride.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

Biodegradation study was conducted for 28 days following the principles of the OECD guideline 301 D for determining the ready biodegradability of the test chemical (Experimental study report, 2018). The study was performed at a temperature of 20°C under aerobic conditions. Aerobic conditions was provided by means of mineral media which is aerated for 20 hours prior to start of the experiment. The test system included control, test chemical and reference substance. Polyseed capsule (mixed culture) was used as a test inoculum for the study. Test inoculum polyseed capsule was composed of blend of specialized microbial cultures and food grade gelatin made by International Laboratory Supply (InterLab), LTD. No pretreatment / preconditioning was given to the test inoculum as the polyseed capsule requires only one hour of stirring to activate it. 1 Polyseed capsule was added in 500 mL DI water and then stirred for 1 hour for proper mixing and functioning of inoculum & settled for 15 minutes to eliminate the bran. Decanted polyseed solution was used as mixed inoculum. Thus, concentration of test inoculum used for the study was 32 ml/l which corresponds to 10E7 to 10E8 CFU/ml. The concentration of test and reference substance (Sodium Benzoate) chosen for both the study was 4 mg/L. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference chemical was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test chemical and reference substance. The % degradation of procedure control (reference substance) was also calculated using BOD & ThOD and was determined to be 78.31 %. Degradation of Sodium Benzoate exceeds 43.37% on 7 days & 61.44% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.07 mgO2/mg. ThOD was calculated as 1.23 mgO2/mg. Accordingly, the % degradation of the test chemical after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 86.99%. Based on the results, the test chemical under the test conditions, was considered to be readily biodegradable in nature.

 

Thus, based on the available information, it indicates that chemical N-acetylsulphanilyl chloride was 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 66.5%). In soil,N-acetylsulphanilyl chloridewas expected to have rapid to moderate mobility based upon a Log KOC value ranging from 1.08 to 2.42, respectively. The half-life in soil (75 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, 33.4% 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 (37.5 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 0.0832% when estimated by EPI Suite version 4.1).

 

Hence it has been concluded that N-acetylsulphanilyl chloride 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 various reliable databases was evaluated to be ranges from 2.24 to 10.43, respectivelyand the octanol water partition coefficient of the test chemical was evaluated to be ranges from 1.55 to 2.05, 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, invertebrate and algae for the substanceMethyl phenylacetateindicates the LC50/EC50 value to be in the range > 2 mg/l to 200 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 water, chemicalN-acetylsulphanilyl chlorideis likely to be not hazardous to aquatic organisms at environmentally relevant concentrations and hence, considered to be ‘Not classified’ as per the CLP regulation.

 

On the basis of available long-term toxicity data forchemicalN-acetylsulphanilyl chlorideof fish, the 28 days NOEC value was evaluated to be  17.079 mg/l and for aquatic invertebrates, the 21 days NOEC value was evaluated to be 9.788 mg/l. Thus, 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.