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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Skin:
Tetrahydromethylphthalic anhydride (MTHPA) is based on the available information (erythema score 2.00, oedema score 1.92) not a dermal irritant according to CLP (1272/2008/EEC). 
In addition, the substance is also not classified according to ANNEX VI table 3.1 (GHS) and table 3.2 (DSD) of Regulation (EC) No 1272/2008 with regard to skin irritation. 
The conditions of the available study are more stringed, in particular the 24 hour exposure period compared with 4 hours of current test methods (described in OECD TG 404), and are thus regarded as worst case scenario. In conclusion the substance is not classified skin irritating based on DSD and CLP.
Eye:
Eye: Highly irritating and classified as Seriously eye damaging according to CLP (1272/2008/EEC) and 67/548/EEC when 0.1 ml are applied to the rabbits eye.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

Skin:

In a primary dermal irritation study (key study, Liggett, 1980), rabbits were dermally exposed to 0.5 ml of methyl tetrahydrophthalic anhydride (MTHPA), for 72 hours. A mean erythema score (24/72 h) calculated over all 6 animals for intact skin of 2 and for abraded skin of 1.58 was observed. The oedema score was determined to be 1.92 for intact skin and 1.50 for abraded skin. Taking the test conditions into account, in particular the 24 hour exposure period compared with 4 hours of current test methods (described in OECD TG 404), MTHPA has not to be classified and labelled as dermal irritant according to CLP (1272/2008/EEC), and according to 67/548/EEC (DSD). In a primary dermal irritation report (supporting study, Smyth, 1969), rabbits were dermally exposed to Methyl tetrahydrophthalic anhydride (MTHPA) on belly. 

In this report, MTHPA is not a dermal irritant. The irritant score of MTHPA is 1 of 6, which means minimal irritating to the skin

Eye:

In a primary eye irritation study (key study, Irie, 1969), 0.01 ml of methyl tetrahydrophthalic anhydride (MTHPA), was instilled into the conjunctival sac of Belgian Hare. Animals then were observed for 10 days. The response to treatment requires MTHPA to be classified as seriously eye damaging according to CLP (1272/2008/EC).

In a supporting primary eye irritation study (Smyth, 1969), MTHPA was instilled into the conjunctival sac of rabbits eyes. An irritation score of 9 (maximum score 10) was determined. Thus, MTHPA was considered to be seriously eye damaging.


Effects on eye irritation: highly irritating

Justification for classification or non-classification

Skin:

Based on the results of the presented skin irritation studies the test substance was not classified and labelled according to Regulation 1272/2008/EC (CLP) and Directive 67/548/EEC (DSD).

Eyes:

Based on the results of the available eye irritation studies, tetrahydromethylphthalic anhydride (MTHPA) was classified as eye damaging category 1 with labelling of H318: causes serious eye damage according to CLP (1272/2008/EC) and as seriously eye damaging (Xi, R41) according to 67/548/EEC.