HDI oligomers, biuret

Endpoint summary

Description of key information

Skin: slightly irritating, not indicative for classification. 
Transient signs of mild skin irritation were observed in the Key study (BASF SE, 1992) and in 2 of the 3  supporting studies. All studies were performed according to or similar to the OECD test guideline 404. 
Eye: not irritating 
In an OECD TG405 study no signs of eye irritation were described (Rhone-Poulenc, 1983)
Respiratory tract: irritating to the respiratory tract
Signs of lower respiratory tract irritation observed in all acute and repeated dose inhalation toxicity studies.

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

The Key study was performed according to the OECD test guideline 404. 0.5ml of the undiluted test substance was applied to the intact skin of 3 rabbits under semiocclusive conditions for 4 h. Slight erythema (scores: 0.33, 1.67 and 1.33) was observed, but was fully reversible within 48 h, 8 d and 72 h, respectively. Edema (scores: 0, 0.33 and 0.33) was reversible within 48 h (BASF AG, 1992).

3 additional studies of acceptable reliability are available to substantiate the test result:

In a guideline-conform study (OECD TG 404), the undiluted test substance was applied to the intact skin of 3 male rabbits (0.5ml, 4h, semiocclusive). No edema or erythema was reported on any animal (Rhone Poulenc Inc. 1983).

A study performed according to OECD TG 404, the undiluted test substance was applied to the intact skin of 6 male rabbits (0.5ml, 4h, semiocclusive). Mild erythma was observed in all animals (grade 1,2), edema (gade 1) was observed in 5 of 6 animals.Though a limited observation period of only 72h has to mentioned as a significant shortcoming of this study, a clear tendency for a full reversibility can be postulated from the raw data (Hazelton, 1986).

Finally a further guideline-conform study (OECD TG 404) is reported (Bushy RRC, 1991). 0.5ml of the undiluted test substance were applied for 4h to the clipped skin of 3 male and 3 female animals under occlusive conditions. Reversible erythema (grade 1 and 2) and edema in one animal were identified as indicators of slight skin irritation.

 

Eye irritation

They study for eye irritation was performed in 3 male rabbits according to the OECD test guideline 405. In brief, 0.1ml of the undiluted test substance were applied to the conjunctival sac of each animal. The treated eyes were not rinsed.

1 and 24h following application all 3 animals displayed mild conjunctival reness (grade1) which was reversible in all animals after 72h. No other signs of eye irritation were described (Rhone-Poulenc, 1983).

Respiratory Tract irritation:

HDI Trimer (biuret) has shown to be a respiratory tract irritant in a variety of acute inhalation bioassays.

For details please consult End Point Summary of chapter Acute Toxicity.

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Dangerous substance Directive (67/548/EEC)

The available experimental test data are considered reliable and suitable for the purpose of classification. Based on the criteria of Directive 67/548/EEC, as amended for the 28^thtime in Directive 2001/59/EC, classification for skin and eye irritation is not warranted.

Though the substance has to be classified as an respiratory tract irritant (Xi, R37).

 

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for the purpose of classification. Based on the criteria laid down in Regulation (EC) No. 1272/2008, as amended for the 2^ndtime in Directive EC 286/2011, classification for skin and eye irritation is not warranted.

Though the substance has to be classified as an respiratory tract irritant (STOT Single Exp. 3, H335: May cause respiratory irritation).