Registration Dossier

Administrative data

Description of key information

Reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was found to be eye irritating in vivo (according to guideline OECD 405) and mild eye irritating in vitro (according to guideline OECD 437). The substance was found  but not skin irritating (according to guideline EU B.46), but skin irritating based on the calculation method. No irritating effects to the respiratory tract were observed in the 90 day repeated dose toxicity study.

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

One in vitro skin irritation study conducted under GLP showed that reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) is not skin irritating. However, the substance 2-methyl-pentane which is classified as skin irritating 2 in Annex VI of the CLP Regulation, is also present in reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) as an impurity. As the concentration of 2 -methyl-pentane observed in other samples of reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) may trespass the concentration limit for classification as skin irritating 2 (10% w/w), reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was assigned the classifcation as skin irritating even if the result of the in vitro skin irritation study indicated no irritating effect.

One in vivo eye irritation study conducted under GLP and according to OECD 405 (key study) showed eye irritation. A previously conducted in vitro study according to the stepwise testing approach (according to OECD 437, BCOP test) showed mild eye irritation.

The results of the in vivo eye irritation study cannot be used for quantitative risk assessment since no dose-response data are available. However, they are used for qualitative risk assessment which consists of classification into a risk category and definition of risk management measures.


Justification for selection of skin irritation / corrosion endpoint:
No adverse effect observed based on experimental study, but skin irritating based on calculation methodvbased on experimental study, but skin irritating based on calculation method

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

One in vitro skin irritation study conducted under GLP showed that reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) is not skin irritant. However due to the observation of the impurity 2 -methyl-pentane in concentration above the concentration limit for classification in some samples, reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was assigned the classifcation as skin irritating.

One in vivo eye irritation study conducted under GLP and according to OECD 405 (key study) showed eye irritation. A supporting in vitro study (according to OECD 437, BCOP test) showed mild eye irritation.

Consequently, reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) has to be classified as eye irritating (Irritating to eyes Cat. 2, H319) and skin irritating (Irritating to the skin Cat. 2, H315) according to the criteria of Regulation (EC) No 1272/2008.

According to the E.E.C Directive 67/548, reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) has to be classified as "irritating to eyes" Xi, R36. As the concentration limit for classification as "irritating to the skin" according to the E.E,.C Directive 67/548 is higher than according to CLP, reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) does not need to be classified as "irritating to the skin" Xi, R38.