[7-hydroxy-8-[(4-sulpho-1-naphthyl)azo]naphthalene-1,3-disulphonato(3-)]aluminium

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of aluminium(3 +) ion (5E)-6 -oxo-5 -[2 -(4 -sulfonatonaphthalen-1 -yl)hydrazin-1 -ylidene]-5,6 -dihydronaphthalene-1,3 -disulfonate for effects in the environment:

 

The chemical aluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonate (CAS no. 15876-47-8) is used in the dyestuff industry. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled foraluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonate. 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

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound aluminium(3 +) ion (5E)-6 -oxo-5 -[2 -(4 -sulfonatonaphthalen-1 -yl)hydrazin-1 -ylidene]-5,6 -dihydronaphthalene-1,3 -disulfonate (CAS no. 15876 -47 -8) 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  aluminium(3 +) ion (5E)-6 -oxo-5 -[2 -(4 -sulfonatonaphthalen-1 -yl)hydrazin-1 -ylidene]-5,6-dihydronaphthalene-1,3-disulfonate is expected to be not readily biodegradable.

                                                                 

Experimental results from the read across substances (CAS: 4548-53-2, 129-17-9, 2611-82-7 and 915-67-3) also indicate that they are not readily biodegradable.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e. estimated to 56.6%). In soil,aluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonatewas expected to have negligible mobility based upon a Log Koc value of 5.2823, respectively. The half-life in soil (120 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, 40.1% of the chemical will partition into sediment according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (541.66 days estimated by EPI suite) indicates that the chemical is persistent in sediment and the exposure risk is moderate to high. 

 

Moreover, its persistent characteristic is also observed in the water compartment according to the Mackay fugacity model level III in EPI suite version 4.1 (2017) with a half-life value of 60 days. This half-life value indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high. 

 

Although the half-life values indicate the chemical to be Very persistent (vP), since only predicted data is available for the substance, it has been concluded that aluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonateis 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 3.162 L/Kg, respectively and the octanol water partition coefficient of the test chemical is 2.3125 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

Although the aquatic toxicity data is not available for the test chemicalaluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonate(CAS no. 15876-47-8), but based on the available short-term eco-toxicity estimations for invertebrates and algae for the read across substances indicates the LC50/EC50 value to be in the range > 100 to 356.2 mg/L whereas the EC0 and LC100 value for invertebrates was determined to be 604.477 mg/l and 6044.77 mg/l, respectively. These value of read across substances suggest that the test substancealuminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonate can be expected to have EC50 value> 100 mg/l and thus 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 foraluminium(3+) ion (5E)-6-oxo-5-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-5,6-dihydronaphthalene-1,3-disulfonate. 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.