Zinc bis(benzenesulphinate)

Endpoint summary

Description of key information

Not skin and eye irritant.

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)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The potential of target substance to cause skin and eye irritation was assessed in vitro.

Skin irritation was assessed according to OECD guideline 439, using human epidermal model EpiDermTM.

No direct MTT reduction was found; no colour interference was supposed as the substance is white.

In main experiment, tissues were exposed to test substance for 60 minutes. Test substance was spread out on 3 moistened tissues and on 2 not moistened tissues. In addition, 3 tissues were used for positive as well as for negative controls.

After removal of test substance, tissues were post-incubated for approximately 42 hours. Three hours incubation with MTT and two hours extraction period with shaking followed then. Optical density (OD570) of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability, calculated as % of mean viability of negative control tissues, was 96.7 % and 100.2 % in moistened and not moistened tissues, respectively, i.e. viability was > 50 %.

Eye irritation was assessed with BCOP test method, according to OECD guideline 437.

Three corneas were used for test substance as well as positive control with 20 % imidazole and negative control with 0.9 % NaCl.

Test item was tested as suspension prepared from test item at 20 % concentration in a 0.9 % NaCl solution.

The closed-chamber method was used, because test item was applicable by micropipette. The opacity and permeability of each cornea were measured. In Vitro Irritancy Score (IVIS), calculated from values of opacity and permeability, was 2.35, i.e. IVIS < 3.

Justification for classification or non-classification

In vitro alternatives, validated and accepted, may be used in classification decisions in categories set by CLP Regulation (EC 1272/2008).

As for skin irritation, the relative cell viability is calculated for each tissue as % of mean of negative control tissues viability, which is set at 100 %.

Cut-off values for prediction of irritation are:

- in case test chemical is found to be non-corrosive (e.g., based on OECD guideline 430, 431 or 435), and shows tissue viability after exposure and post-treatment incubation ≤ to 50 %, test chemical is considered to be irritant to skin, category 2.

- test chemical may be considered as non-irritant to skin, if tissue viability after exposure and post-treatment incubation is > 50 %.

A single test run composed of 3 replicate tissues should be sufficient for a test chemical when the classification is unequivocal. However, in cases of borderline results, such as non-concordant replicate measurements and/or mean percent viability equal to 50 ± 5 %, a second run should be considered, as well as a third one in case of discordant results between the first two runs.

As for eye irritation, the IVIS cut-off value for identifying test item as inducing serious eye damage (category 1) and test item not requiring classification for eye irritation or serious damage are:

IVIS       

≤ 3 no category

> 3; ≤ 55 no prediction can be made

> 55 category 1

Based on experimental findings, test substance was not classified for skin and eye irritation within the CLP Regulation (EC 1272/2008).