Registration Dossier

Diss Factsheets

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

There are no data on skin sensitisation available.

Tert-butylisocyanate is classifed as C, R34 (corrosive, causes burns). Studies for sensitisation are therefore scientifically not justified and are precluded on grounds of animal welfare.


Migrated from Short description of key information:
no data

Respiratory sensitisation

Endpoint conclusion
Additional information:

Due to RL 67/548/EEEC isocyanates have to be classified as skin and respiratory sensitisers R42/43. According RL

1272/2008/EG (GHS) a classification as Skin Sens.1 (H 317: May cause an allergic skin reaction) is sufficient because only diisocyantes have to be classified as respiratory sensitisers.

There are no data on respiratory sensitization available. Tert-butylisocyanate is a monoisocyanate. The UK Health and Safety Commission Working Group on the Assessment of Toxic Chemicals, Working Group on Action to Control Chemicals concluded performed an assessment of the potential for isocyanic acid and other monoisocyanates to cause respiratory irritation and sensitization (WATCH Committee Paper WATCH/2008/4, 17 Jun., 2008; http://www.hse.gov.uk/aboutus/meetings/iacs/acts/watch/170608/p4.pdf) and came to the following conclusion: “With the exception of methyl isocyanate, information on the toxicity of the monoisocyanates is sparse. There is no direct evidence that any of the monoisocyanates can cause respiratory sensitisation. … However, this indirect information on the allergenicity and immunoreactivity of the monoisocyanates is very limited, and insufficient to reliably inform on their potential to cause respiratory sensitisation.” A similar conclusion was drawn by the German MAK commiss concerning the monoisocyanates in 2009 (MAK- und BAT-Werteliste 2009).

In addition it should be also mentioned that the ‘default’ assumption of the former EU hazard classification systems that all isocyanates have the potential to cause respiratory sensitisation is not in agreement with the strategy for evaluating respiratory sensitisation data in the Technical Guidance Document (TGD) on information requirements for REACH (R.7a; page 256ff). The TGD proposes that, in the absence of specific health effects data, only diisocyanates that also meet the criteria for classification for skin sensitisation are presumed to be respiratory sensitisers.


Migrated from Short description of key information:
no data

Justification for classification or non-classification

There are no data on skin or respiratory sensitisation available.

Due to the fact that the test substance is an Isocyanat it has to be classified with R42 and R 43 (REACH Regulation, Classification and Labeling, Appendix VI).

For respiratory sensitisation a classification according GHS is not justified (see Discussion)