5-oxo-1-(4-sulphophenyl)-2-pyrazoline-3-carboxylic acid

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid for effects in the environment:

5-oxo-1-(4-sulphophenyl)-2-pyrazoline-3-carboxylic acid [Pyrazolone T] (CAS no. 118-47-8) has a wide variety of uses such as: agrochemical intermediate, intermediate for chemical synthesis, pharma intermediate, dyestuff intermediate and as a laboratory agent. The aim of the PBT assessment was to evaluate whether this chemical fulfils the PBT criterion within Annex XIII. The PBT assessment were based on toxicological information in conjunction with standardized environmental fate- and bioaccumulation 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:

 

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%). The Koc-value was estimated to 10 at 25ºC (KOCWIN program) indicating very high mobility and negligible adsorption potential.

The tested chemical is therefore expected to leach from soil. The exposure risk to soil-dwelling organism should therefore be moderate to low.

If released in to the environment, 30.6% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2016). However, the short half-life (15 days estimated by EPI suite) indicates that 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 0% when estimated by EPI Suite version 4.1). Hence it has been concluded that 5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid 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 is estimated to be 3.162 L/kg (calculated by EPI suite version 4.1, 2016) and the Log Kow value is approx. -1.83 at 25ºC. 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

The lowest reported toxicity values from the available short-term eco-toxicity estimations for fish, invertebrates and algae are LC50 = 646000 mg/L, EC50 = 132 mg/L and EC 50 = 49.87 mg/L, respectively. These values suggest classification for aquatic toxicity as per the CLP criteria but classification for aquatic toxicity will not be applicable as per Annex XIII criteria for all of the tropic levels and the same is based on the above mentioned estimation studies.

 

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.