p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonic acid

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl] benzenesulphonic acid for effects in the environment:

 

The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl] benzenesulphonic acid. 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

Biodegradability of test chemical 4-{4-[(E)-2-{2-methoxy-5-methyl-4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl} benzene-1-sulfonic acid (CAS no. 60958-41-0) was estimated by using OECD QSAR tool box v3.3 by considering five closest read across chemicals with log Kow as primary descriptor. The percent degradation of test chemical  4-{4-[(E)-2-{2-methoxy-5-methyl-4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl} benzene-1-sulfonic acid was estimated to be 0.142 % by considering BOD as parameter and microrganisms as inoculum in 28 days. On The basis of value of percent biodegradabilty it is concluded that this test chemical is not readily biodegradable in 28 days.

 

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 4-{4-[(E)-2-{2-methoxy-5-methyl-4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl}benzene-1-sulfonic acid (CAS no. 60958 -41 -0) 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 4-{4-[(E)-2-{2-methoxy-5-methyl-4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl}benzene-1-sulfonic acid is expected to be not readily biodegradable.

 

Experimental results from the read across substances (CAS no: 20317-19-5 and 2580-78-1) also indicate that they are not readily biodegradable.

 

Thus, based on the above available information, it has been concluded thatp-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl] benzenesulphonic acidis likely to be 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 estimated BCF value from authoritative database was determined to be ranges from 1-3.162, respectivelyand the octanol water partition coefficient of the test chemical was -2.73, 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 estimations for invertebrates and algae for the substancep-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl] benzenesulphonic acidindicates the LC50/EC50 value to be in the range 390.289 – 398.494 mg/L, respectively. These value suggest that the substance is not likely to be hazardous to Aquatic organisms at environmentally relevant concentrations and can be considered to be ‘not classified’ as per the CLP regulation.

 

There are no available long-term toxicity evaluations forp-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl] benzenesulphonic acid. 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 criterion but does not fulfil the B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.