Benzoic acid

Endpoint summary

Description of key information

Skin irritation/corrosion:
The test substance is not irritating to the skin in standard animal irritation studies.
Eye irritation:
The test substance is severely irritating to the eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation/corrosion:

The test substance is not irritating to the skin (below classification threshold) in standard animal irritation studies.

1) A primary skin irritation study was conducted according to EU Method B.4 using rabbits (Daamen, 1988). Supporting study.

The test substance was considered as minimally irritating to the skin.

2) An acute toxicity study in rats (Goldenthal, 1974) is available which is supporting study.

These studies showed the test substance is not irritating. However, the test substance dissolved in ethanol (at concentrations of 1-20 %) was shown to elicit a concentration dependent reaction in the guinea pig ear swelling test (Lahti, 1984). By contrast, no response was noted in the rat or mouse ear for a concentration of 20 % (Lahti, 1985). In the literature, skin effects have frequently been reported for humans. Animal data from the Guinea pig ear swelling test support the observations in humans. The test substance produces no skin response in the rat or mouse, but the Guinea pig's ear reacts by swelling (Lahti, 1985). This test is considered as a predictive assay for evaluating the ability of substances to produce non-immunological contact urticaria.

Eye irritation:

The test substance is highly irritating to the eyes.

1) An eye irritation study was conducted according to EU Method B.5 using rabbits (Daamen, 1988). Key study.

The test substance was severely irritating to rabbits eyes under the conditions of the test.

2) An acute toxicity study in rats (Goldenthal, 1974) is available which is supporting study.

This study showed the test substance was an extremely irritating and corrosive substance.

Other publications were identified and provided similar results.

Justification for selection of skin irritation / corrosion endpoint:
This study was conducted according to a reliable method using guinea pig, rat and mouse.

Justification for selection of eye irritation endpoint:
This study was conducted according to EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion) using rabbits.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: highly irritating

Justification for classification or non-classification

In the supporting study on skin irritation/corrosion: Mean scores at 24, 48 & 72 hours for erythema were < 2.3 (actual value 0.22) for oedema were < 2.3 (actual value 0.11). In addition all reactions were fully reversible within the observation period. However, the test substance should be considered a skin irritant (CLP: Skin Irritation Category 2 (H315); Directive 67/548/EEC: Xi; R38) since human data shows that the test substance is capable of inducing non-immunological contact urticaria, which is regarded as an irritation reaction as supported by findings of Lahti, 1985 in Guinea-pigs.

In the key study on eye irritation: Effects on the cornea, iris or conjunctiva were not fully reversed within an observation period of normally 21 days (Actually two animals on cornea, one animal on iris and three animals on conjunctiva were not reversed within 21 days).

Therefore in accordance with Regulation (EC) No. 1272/2008 Table 3.3.1 the substance is classified as "Irreversible effects on the eye (Category 1)" for the serious eye damage/eye irritation endpoint.