2-(2-butoxyethoxy)ethanol

Endpoint summary

Description of key information

SKIN IRRITATION:
4 studies including key study with conclusion; not irritating
1 repeat application study by dermal route with conclusion: slight irritation
EYE IRRITATION
Slightly irritating
Irritating
Highly irritating

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)

Additional information

A number of studies are available that examined the skin irritancy potential of 2 -(2 -butoxyethoxy)ethanol, including one which is available as a full study report and is to a guideline protocol. All of the studies showed a low skin irritancy potential, even when applied repeatedly.

There is adequate data available on the eye irritancy potential for this substance. Three studies are used on a weight of evidence approach. All of the studies have slight shortcomings. One study shows minimal irritancy, and whilst this is reliable, it is relatively old and only uses half of the normal instillation volume of test substance. The second study shows moderate eye irritancy and again, whilst considered reliable, the results are not available in full detail. The third study available shows marked irritancy with some effects persistent for at least 3 weeks. This study uses a washout but not until 72 hours, later than normally recommended.

Effects on eye irritation: irritating

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

This substance is not irritating to the skin following single application and does not meet the criteria for classification as a skin irritant

under either directive 67/548 or regulation 1272/2008.

The data available for eye irritancy is at first sight contradictory when it comes to interpreting it for classification purposes. However, the results can be interpreted as consistent with the effects seen for the butyl glycol ether family (mono/di/tri ethylene glycol butyl ethers) The consistent pattern seen is for moderate eye irritancy in terms of immediate effects but sometimes persistent effects which can take more than 21 days to resolve. However, there is also data for the mono member of the family which shows that the washout option can be key to the persistency of effects, with a washout at 24 hours (current guideline recommendation) playing an important role in reducing the persistency of effects seen. The data for 2 -(2 -butoxyethoxy)ethanol is consistent with this in that the study using a reduced quantity of substance elicited barely any irritancy whilst the study with delayed washing showed severe irritancy. Humans have a marked lachrymatory (ie a washing) response to irritants which is lacking in rabbits. On this basis, the interpretation of the data is that humans are not likely to see the persistent effects observed in the Huels study and the response is more likely to be as seen in the other two studies and those on other butyl glycol ethers that used 24 hour washing. On this basis, a classification of 'irritant' seems most appropriate.

There is limited data available on the eye irritancy potential and insufficient information to make an unequivocal comparison with classification criteria. However, the data as a whole provides enough information for evaluation of the eye irritation potential and suggests that this substance should be classified as an eye irritant under both directive 67/548 and regulation 1272/2008. This conclusion is in line with similar glycol ethers which are also known to be irritating to the eye.