Hydrogen [4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of hydrogen [4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt for effects in the environment:

 

Hydrogen[4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt (CAS no. 129-17-9) is used mainly as a food colourant. 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 fulfils the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

28-days Manometric respirometry test following the OECD guideline 301F was performed to determine the ready biodegradability of the test item Hydrogen [4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt (CAS No. 129-17-9). The BOD₂₈value of the substance was observed to be 0.0335 mgO₂/mg. ThOD was calculated as 1.892 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 1.77%. Based on the results, the test item, under the test conditions, was found to be non-biodegradable at 20 ± 1°C over a period of 28 days.

 

Estimation Programs Interface Suite (EPI suite, 2016) was run to predict the biodegradation potential of the test compound Hydrogen[4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt (CAS no. 129-17-9). The screening tests ready biodegradability of the test substance was calculated using the software BIOWIN v4.10. The results indicate that Hydrogen[4-[4-(diethylamino)-2',4'-disulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene]diethylammonium, sodium salt is not expected to be readily biodegradable in nature.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is sediment and soil (i.e.estimated to 68.8% and 29.9% respectively). The Log Koc-value was determined experimentally to 3.628 at 25ºC (OECD Guideline 121) indicating negligible mobility and very high adsorption potential. The tested chemical is therefore not expected to leach from sediment and soil.

The half-life in sediment and soil (541.66 days and 120 days respectively, estimated by EPI suite) indicates that the exposure risk to sediment and soil-dwelling organism should therefore be moderate to high.

 

If released in to the environment, only 1.44 % of the chemical will partition into water, according to the Mackay fugacity model level III in EPI suite version 4.1 (2016). However, the half-life (60 days estimated by EPI suite) indicates that the exposure risk to aquatic animals is moderate.

 

On the basis of the above mentioned half-life values, the chemical is classified as a persistent chemical (P) but not very persistent (not vP) since only estimated half-life values for the same are available.

 

 

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, 2015) and the experimental Log Kow values is -2.783 at 25ºC (OECD Guideline 107, 2015). 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

Most of the available short-term eco-toxicity estimation for fish, invertebrates and algae for the substance as well as its read-across substances indicates the LC50/EC50 value are above 100 mg/L indicating that the substance is classified as non-hazardous as per the CLP criteria.These values suggest classification for aquatic toxicity will not be applicable for all of the tropic levels.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.