Registration Dossier

Administrative data

Description of key information

In conclusion, the test substance MBT showed a practically non-irritating potential to rabbit skin (Monsanto Co. 1975). The even very low skin irritation potential is confirmed by another skin irritation study (Monsanto Co. 1974). Moreover, no visible skin changes were observed in any of the 50 human volunteers in a Repeated Insult Patch Test after application of the test substance (Monsanto Co. 1976). A rather slight and transient eye irritation potential is noted in an eye irritation study (Monsanto Co. 1975). This finding was confirmed by another eye irritating study, which also revealed very slight and transient eye irritating effects of MBT (Monsanto Co. 1974). 

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:
no adverse effect observed (not irritating)

Additional information

Skin

Non-human information

The skin irritation potential of the test substance MBT was evaluated in a skin irritation study with six New Zealand Albino male and female rabbits (Monsanto Co.1975). The finely ground test substance (500 mg) moistened with water was applied under semi-occlusive dressings to clipped intact and abraded skin of 6 New Zealand albino rabbits for 24 hours. A 7-day observation period followed the test substance application. The test substance MBT was practically non-irritating to rabbit skin (mean irritation score intact and abraded skin: 0).

This finding is confirmed by another skin irritation study, which also indicated a very low skin irritation potential of the test substance (mean irritation score intact and abraded skin: 0, Monsanto Co. 1974).

Human information

The potential for MBT to cause primary skin irritation and/ or sensitization was assessed in Repeated Insult Patch Test with 50 human volunteers (Monsanto Co. 1976). The test substance was tested as 50 % w/v solution in dimetylphthalate. No visible skin changes were observed in any of the 50 individuals tested.

Eye

Non-human information

The eye irritating potential of the test substance MBT was evaluated in an eye irritation study with six New Zealand albino male and female rabbits (Monsanto Co 1975). 100 mg of the finely ground test substance was placed into the conjuntival sac of six male and female rabbits. A 7-day observation period followed the application of the test substance. Eye response were scored in accordance with the Federal Hazardous substances Act (F.H.S.A.), 21 CFR, § 191.12 (1964).

The test substance was slightly irritating to the rabbit eye (irritation score 24, 48, and 72 hours: 3.2/110.0). Effects on the conjunctivae were noted in all animals at 24 hours (mean score 24 h: 8.6/110) but were reversible within 72 hours. The test substance was classified as slightly eye irritating.

In another eye irritation study with New Zealand Albino rabbits very slight and transient eye irritating effects were noted after treatment with MBT (irritating score 24, 48 and 72 hours: 1.3/110.0). Slight erythema and discharge were observed at 24 hours (mean score 24 h: 4.0/110) and were reversible within 48 hours. The test substance was classified as not eye irritating (Monsanto Co. 1974).

Justification for classification or non-classification

No classification is required according to the classification criteria 67/548/EWG and regulation no. 1272/2008 (GHS).