Registration Dossier

Administrative data

Description of key information

Limited irritation response (only very slight after 60 minutes) on non-abraded under semi-occlusive conditions. Slight to moderate skin irritation on abraded skin with longer exposure and occlusive conditions. Slight irritation in the eye.  Does not meet the criteria for classification. 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Additional information

Based on the available skin irritation data on rabbits, it can be assumed that TNPP is a very slight to moderate irritant to the skin, varying according to tests conditions used. In the key study (Tay 2001), TNPP showed only very slight irritation after 1 hour, fully reversible at 24 hours, when administered to intact skin in a semi-occlusive 4 -hours exposure. This study was done using OECD 404 under GLP conditions and with a test substance that is fully characterised as >99% pure TNPP. An older study (Seibert, 1982), where the test substance was not characterised but is reported to be TNPP, a 24-hour exposure on intact and abraded skin under occlusive conditions elicited moderate irritation properties under these more severe conditions. The effects from this study were fully reversible within 7 days.

The two available studies indicate that TNPP is a slight irritant to the eye. In all cases, the effects were generally reversed within a few days.

No information is available from human studies.


Effects on skin irritation/corrosion: slightly irritating

Effects on eye irritation: slightly irritating

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

According to the cutaneous and eye irritation test methods, TNPP should not be classified as an irritant to skin and eye.