Hydroxylamine-O-sulphonic acid

Endpoint summary

Description of key information

Skin Irritation:

The in vivo study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver. According to in vitro study,it was concluded that test chemical was considered to be corrosive to human skin. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category 1".

Eye Irritation:

The study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study need not be conducted because the substance is a strong acid (pH <= 2.0) or base (pH => 11.5)

Justification for type of information:

The study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study need not be conducted because the substance is a strong acid (pH <= 2.0) or base (pH => 11.5)

Justification for type of information:

The study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation:

In different studies, the test chemical has been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in- vitro and in-vivo experimental conducted in human and rabbits which have been summarized as below:

The in vivo study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver.

In in vitro experimental study report, the dermal irritation potential of test article was determined according to the OECD 439 test guideline for this study. The MatTek EpiDerm™ model was used to assess the potential dermal irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to the test article and controls for ~one hour, followed by a 42 hour post-exposure recovery period. The viability of each tissue was determined by MTT assay. The MTT data show the assay quality controls were met and passed the acceptance of criteria. The mean of OD  for test chemical was determined to be 0.548 and 0.238 for 3 min. enpoint and 1 hour endpoint, respectively. The Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 19.3% and 8.2 % for 3 min. enpoint and 1 hour endpoint,respectively. Hence, under the current experimental test conditions it was concluded that test chemical was considered to be corrosive to human skin.

All these studies lead to a conclusion that Test chemical is indeed corrosive to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “category 1 -corrosive”.

Eye Irritation:

The study need not be conducted because the substance is a strong acid (pH<=2.0). The experimental pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) was 1.81. Hence this endpoint was considered for waiver.

Justification for classification or non-classification

According to the CLP Regulation (EC n. 1272/2008) and based on the low pH of Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) (pH=1.81), the classification Skin Corrosive 1B and Eye Damage 1 is proposed for Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8).