α,α,α,4-tetrachlorotoluene

Endpoint summary

Description of key information

Skin irritant

Eye irritant

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)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

In the key study, experimental data obtained after a single administration of 0.5 mL of the test article in the New Zealand White rabbit (3 animals) show that no untoward clinical signs or behavioral alterations were observed. Signs of dermal irritancy were observed in all treated rabbits. The test article, when administered by dermal route to rabbits under the experimental conditions adopted, has to be considered IRRITANT for the skin.

The first supporting study was conducted on the rabbit's skin in accordance with the OECD guidelines for Testing of Chemicals 404. Interpretation of results was based on the nature, intensity and reversibility of the observed responses. Under test conditions the substance resulted to be irritant to the skin.

In the second supporting study, the authors tested primary skin irritation of the test substance according to the U.S. Consumer Product Safety Commission, Code of federal regulations, title 16, section 1500.41 (patch test in rabbits). The skin (left test site intact and right site abraded covered with occlusive gauze) of six white New Zealand Albino rabbits. The exposure period was 24 hours and the skin was checked after 24h of exposure, 48h and 72h (i.e. 24h and 48h respectively after removal of patch with test substance). A final check was done after 8 days.

After 8 days the evaluation value for edema was 4 (i.e. high irritation/corrosivity) for all test sites except one, which scored 3, therefore no reversibility of signs was detected after the observation period. In front of such evidences, the test substance should be considered as a potential skin corrosive for rabbits. However, the current guidelines suggest an exposure period of up to 4 hours and not 24 h. In addition for the CLP Regulation n° 1272/2008 EC a substance can be defined as skin corrosive if no reversibility of signs is observed after 21 days. Summarizing, due to the long exposure of the animals to the substance, due to the gap between the observation period of the study and the one requested per CLP purposes, and last, due to the lack of information on the composition of the batch tested, this study cannt be used for assessment.

Eye irritation/corrosion

In the first study, the authors tested eye irritation as a result of exposure to the test substance according to the U.S. Consumer Product Safety Commission, Code of federal regulations, title 16, section 1500.42 (test for eye irritants). The right eye of six white New Zealand Albino rabbits was exposed to the test substance, while the left eye was used as control. Eyes were checked after 24h, 48h and 72h of exposure using a ophthalmoscope. A final check was done after 8 days and slight irritation had practically disappeared. Conjunctiva redness and chemosis resulted to have a score of 2, according to Draize, in at least four animals over six and no reversibility was observed after 8 days. According to the CLP Regulation n° 1272/2008 EC, a substance can be considered as corrosive if no reversibility of signs is observed during 21 days after application. Due to the gap between the two observation periods, no corrosivity effect can be attributed to the substance, but an irritating effect was nevertheless observed and for this reason, under test conditions the substance can be considered as irritant to the eye. Although the composition of the substance tested is unknown and the test was conducted in the early 1980s, in a conservative approach, this study was considered as the key study for this end-point.

In the supporting study, the irritant /corrosive potential of the test substance was evaluated on the rabbit's eye, in accordance with the OECD guidelines for Testing of Chemicals 405. Interpretation of results was based on the nature, intensity and reversibility of the observed responses. Under test conditions the substance resulted to be not irritating to the eye (Exposure period of 24 hrs).

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), a substance is considered skin irritant and allocated to category 2 if:

(1) Mean score of ≥ 2,3 and ≤ 4,0 for erythema/ eschar or for oedema in at least 2 of 3 tested animals from gradings at 24, 48 and 72 hours after patch removal or, if reactions are delayed, from grades on 3 consecutive days after the onset of skin reactions; or

(2) Inflammation that persists to the end of the observation period normally 14 days in at least 2 animals, particularly taking into account alopecia (limited area), hyperkeratosis, hyperplasia, and scaling reactions; or

(3) In some cases where there is pronounced variability of response among animals, with very definite positive effects related to chemical exposure in a single animal but less than the criteria above.

Under test conditions the substance exerted effects to the skin with a mean score value below 2.3. However, the signs were not fully reversible within 14 days. The substance is therefore considered as Skin Irritant Category 2.

According to the CLP Regulation (EC 1272/2008), a substance is considered eye irritant and allocated to category 2 if:

- it produces in at least 2 of 3 tested animals a positive response of:

(a) corneal opacity ≥ 1; and/or

(b) iritis ≥ 1; and/or

(c) conjunctival redness ≥ 2; and/or

(d) conjunctival oedema (chemosis) ≥ 2

calculated as the mean scores following grading at 24, 48 and 72 hours after instillation of the test material, and which fully reverses within an observation period of normally 21 days.

Under test conditions, conjunctiva redness and chemosis resulted to have a score of 2, according to Draize, in at least four animals over six and no reversibility was observed after 8 days. No data at 21 days is available. Due to the gap between the two observation periods, no corrosivity effect can be attributed to the substance, but an irritating effect was nevertheless observed and for this reason, the substance can be considered as Irritant to the Eye Category 2.