Linalyl acetate

Endpoint summary

Additional information

Skin irritation:

In the key study according to OECD TG 404, 0.5 ml of the substance was applied for 4 hours undiluted on the skin of rabbits under semiocclusive conditions (ECETOC 1995). The substance was tested in two test runs using 3 and 4 rabbits respectively. Mean erythema scores (24, 48, 72h) were 2 in 5/7 animals and a lack of reversibility was observed in 6/7 animals for erythema and 3/7 animals for edema (7 day observation period). At the end of the observation period, slight to marked desquamation was found in 6/7 animals, respectively. Based on these findings, the substance is judged to be irritatin to skin.

In the supporting study (BASF test), linalyl acetate was applied for 1 min, 5 min, 15 min, and 20 hours undiluted onto the skin of 2 rabbits under occlusive conditions (BASF AG 1969). Application for 5 min, 15 min and 20 hours resulted in desquamation at the end of the observation period of 8 days and a mean erythema score (24, 48h) >=2 in 2/2 animals. For the shorter application times the occlusive coverage might play a minor role, so that the skin irritation effects are considered to be closely related to the intrinsic properties of the test substance. Therfore, these data provide further evidence, that linalyl acetate is irritating to the skin.

In a 48 hour closed patch test on the backs of 50 adult male volunteers, 0.05 g of linalyl acetate (32% in acetone) was topically applied by 15 mm patches (Motoyoshi 1979). No dermal reactions were observed. Considering a circular patch with a 15 mm diameter, an area of approx. 2 cm2 has been exposed. Application of 0.05 g test substance containing 32 % linalyl acetate would result in an applied dose of 8000 µg/cm2. Therefore, at a dermal load of 8000 µg/cm2, no skin irritation was observed after 48 hour occlusive application.

Eye irritation:

In the key study, i.e. a BASF industrial hygiene orientating investigation study, linalyl acetate was tested in twoVienna White rabbits (BASF AG 1969). Eyes were left unwashed after application of 0.05 ml linalyl acetate and the animals were observed for 8 days. Both animals developed slight conjunctival redness (score 1 in 2/2 animals after 24 h), which completely resolved on day 2 in both animals. No information was given concerning corneal opacity and iritis, however, these parameters were generally assessed in this test type, and the absence of adverse effects on cornea and iris can be assumed under the chosen test conditions.

Considering the relevant eye irritation study of the metabolically related substance Linalool (CAS No. 78 -70 -6) on eye irritation (according to OECD TG 405), the weak irritating potential - observed in the study using linalyl acetate - can be confirmed (BASF 1988). Mean scores (3 animals; 24, 48 and 72 h) for cornea (1.0); iris (0.6); conjunctiva redness (2.3); conjunctiva chemosis (0.4) demonstrate a certain eye irritating potential of linalool under the test conditions chosen. The effects seen on cornea in one animal were fully reversible within 15 days; all other effects observed in all animals were fully reversible within 8 days.

Further studies, available as short references from secondary sources, report very slight conjunctival redness following treatment with linalyl acetate, which returned to normal within one day (Troy 1977) or describe superficial corneal effects with slight conjunctivitis in rabbits, which resolved within 4 days (Quest 1983).

Taken together, slight and reversible (<7 days) eye irritation potential can be attributed to linalyl acetate.

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Skin:

The present data fulfill the criteria laid down in 67/548/EEC and 1272/2008/EEC, and a classification "irritating to skin" (R38) and "skin irritant" (category 2) is warranted.

 

Eye:

The present data on eye irritation do not fulfill the criteria laid down in 67/548/EEC. According to 1272/2008/EEC, a classification as "irritating to eyes" (Category 2) is warranted. According to UN-GHS, a classification as " mildly irritating to eyes" (Category 2B) is warranted.