Benzene-1,2,4-tricarboxylic acid 1,2-anhydride, oligomeric reaction products with ethane- l,2-diol

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The data requirement is filled by using data from a structurally-similar member of the category of Selected Cyclic Acid Anhydrides, ZAN 573, 5-Isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, reaction products with 1,2-propanediol.

ZAN 573 is sensitising in the LLNA at concentrations of 50%, 25% and 10% in DMF. The EC3 is 2.1%, a "moderate" sensitiser (where the concentration resulting in an EC3 is ≥1% and < 10%, according to ECETOC Technical Report No.87, 2003).

As ZAN 573 and BECKOPOX(TM) EH 694 are UVCBs, there is insufficient data to determine the species which is responsible for the sensitisation. The sensitiser trimellitic anhydride is present as a residual in both substances.

Migrated from Short description of key information:
A structurally-similar substance is a dermal sensitiser in the LLNA.

Justification for selection of skin sensitisation endpoint:
experimental data on a structurally-similar chemical within the category of Selected Cyclic Acid Anhydrides

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Respiratory sensitisation is demonstrated and discussed in the repeated dose inhalation test results for trimellitic anhydride (Leach, Hatoum and Derrick, 1988). Category members trimellitic anhydride and phthalic anhydride have been reported to be respiratory sensitisers in occupational settings. Therefore, BECKOPOX(TM) EH 694 is assumed to have the potential to cause respiratory sensitisation. Additionally, the commercial product contains trimellitic anhydride at levels requiring classification for sensitisation.

A category approach is used to support the assessment of the sensitisation endpoint. The hypothesis for the category of cyclic acid anhydrides is the similar chemical behaviour and analogous breakdown products in environmental and biological systems. The common functional group is a 1,3-dioxo-1,3-dihydro-2-furan ring (i. e., a cyclic acid anhydride) directly attached to an aromatic ring. The cyclic anhydride moiety is quickly hydrolysed to form a dioic acid. The cyclic acid anhydride moiety and its dioic acid derivatives are the principal loci of toxicity, rather than the remainder of the molecule. Within the category, oligomeric forms of the cyclic acid anhydrides are less likely to be absorbed across biological membranes than the simple, monomeric forms, so that this read-across represents the worst case scenario. The read-across information to acceptable to fulfil the information requirements of the REACH Annexes VII-X, to be the basis for classification and labelling decisions, and for risk assessment.

Migrated from Short description of key information:
The substance is considered to be a respiratory sensitiser.

Justification for classification or non-classification

The substance is classified as a dermal sensitiser, Category 1, and a respiratory sensitiser, Category 1, based on test results, similar behaviour of category members and content of residual trimellitic anhydride in the commercial product.