2-(2-ethoxyethoxy)ethanol

Endpoint summary

Description of key information

Skin irritation: Not irritant in a key study supported by a further 7 studies with additional information confirming a lack of irritancy
Eye irritation: Not irritant in key study supported by a 13 studies, some of good quality, confirming a lack of significant irritancy potential

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 IRRITATION

In an irritation study in albino rabbits, 2 -(2'-ethoxyethoxy)ethanol was applied to 6 animals on to abraded and intact skin under occlusion. The animals were restrained during a 24hr exposure at the end of which the patches were removed and the reactions scored for erythema and edema immediatly and 72 hours afterward. The average irritation score was 0.5. During observations alongside a 24 hour exposure dermal toxicity study, male NZ white rabbits were exposed topically to 2 -(2 -ethoxyethoxy)ethanol. At doses up to 22.5g/kg, only slight skin irritation was observed. This study does not provide sufficient information to allow comparison with the criteria for classification for skin irritancy but the data suggests that skin irritancy is not an important characteristic of the substance, especially bearing in mind the prolonged exposure period.

In a well reported irritation study in White Vienna rabbits, 2 -(2'-ethoxyethoxy)ethanol was applied to pairs of animals under occlusion. Exposure time was for 1, 5, 15mins and 20 hours. For the longest exposure, there was no sign of odema and mild erythema which disappeared in one animal by 72 hours and by 7 days in the second animal. On these results, the substance would not be classified as a skin irritant.

EYE IRRITATION

In a well conducted guideline and GLP study, 0.1ml of 2 -(2 -ethoxyethoxy)ethanol was instilled into the right eye of three New Zealand White male rabbits. Conjunctival, iris and corneal scores were determined at 1hr, 24hrs, 48hrs and 72hrs after administration. Mild transient iritis and conjunctival effects were observed in some animals but no corneal response. All symptoms reversed within 72 hours.

A well reported study assessed the eye irritancy potential of 2 -(2 -ethoxyethoxy)ethanol along with a number of other test substances in rabbits. Even without a washing stage, the substance showed minimal iritis or corneal effects and minimal chemosis. Mild to moderate onjunctival effects were seen but insufficient to warrant classification. All significant effects appeared to reverse within 72 hours.

In an old study that followed the basic principles of the later OECD guideline study, the eye irritation potential of 2 -(2 -ethoxyethoxy)ethanol in pure form was examined in the rabbit. Results were expressed in terms of the amount of material required to cause a particular level of irritation. The study did not report on all end points normally used to determine eye irritancy classification against EU classification criteria and did not use the Draize scoring system making interpretation difficult. However, the substance gave similar results to other substances that are not normally associated with eye irritancy. This observation can be used as supportive information.

In a study to determine the eye irritation potential of 2 -(2'-ethoxyethoxy)ethanol, the substance was instilled undiluted into the eyes of rabbits 1, 3, 6, 7 and 13 times, over 2, 4, 7, 26 and 50 hour periods. Animals were intravenously injected Evans blue dye 1 hour after instillation and sacrificed 1 hour later. Corneal and conjunctival edema determined as a decrease in percentage of dry tissue, was significantly elevated at all time points compared to control rabbits. Similarly, serum extravasion in conjunctivae and blood/aquous humor barrier disruption determined as an increase in Evans blue dye diffusion was increased at all time points with the test substance compared to control animals. When the same parameters were measured following injection of the dye 24 hours after a single instillation of the substance, only the diffusion of the dye in the conjuctivae was still significantly increased in comparison to control animals suggesting reversibility for the other endpoints after a single instillation.

In a study to determination the eye irritation potential of 2 -(2'-ethoxyethoxy)ethanol, the substance was instilled undiluted into the right eye of rabbits once and any effects examined and graded at 2hr, and then daily for up to 11 days, however, only values for 2hrs, and 3, 7, and 11 days are available. Corneal and conjunctival edema was also determined as a decrease in percentage of dry tissue, and serum extravasion in conjunctivae was determined as an increase in Evans blue dye diffusion, 2hrs and 24hrs after instillation. Corneal thickness was also mesured.

In a study that approximately to a guideline eye irritancy study, albeit with reduced numbers of animals and observation time points, the reaction of rabbit eyes to the substance 2 -(2 -ethoxyethoxy)ethanol was sufficiently mild that it was possible to conclude that the substance has very low eye irritancy potential and would not meet the criteria for classification as an eye irritant.

Justification for classification or non-classification

The conclusion from the available data is that the substance does not warrant classification as a skin irritant.

The conclusion from the available reliable and consistent data is that the substance does not warrant classification as an eye irritant.