Hydroxylamine-O-sulphonic acid

Endpoint summary

Description of key information

Acute oral toxicity:

Data available for the structurally similar and closely related read across chemicals has been reviewed to determine the acute oral toxicity of the test chemical Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8). The studies are as mentioned below:

1. Acute oral toxicity study of test chemical was conducted in rat at the concentration of 2000 mg/kg bw. 50% mortality was observed at 2000 mg/kg bw. Therefore, LD50 was considered to be 2000 mg/kg bw, when rats were treated with test chemical via oral route.

2. Acute oral toxicity study of test chemical was conducted in mice at the concentration of 1100 mg/kg bw. 50% mortality was observed at 1100 mg/kg bw. Therefore, LD50 was considered to be 1100 mg/kg bw, when mice were treated with test chemical via oral route.

Thus, based on the above summarised studies, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) and it’s structurally similar and closely related read across substances, it can be concluded that LD50 value is between 300-2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) can be classified as “Category 4” for acute oral toxicity. Hence, Hydroxylamine-O-sulphonic acid is toxic for acute oral toxicity at the dose range of 1100-2000 mg/kg bw.

Acute Inhalation toxicity: 

Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) has very low vapour pressure (1.52E-14 Pa), so the potential for the generation of inhalable vapours is very low. Also the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be highly unlikely and therefore this end point was considered for waiver.

Acute Dermal Toxicity:

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

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data of read across substances

Justification for type of information:

Data for the target chemical is summarized based on the structurally similar and closely related read across chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

WoE report is based on 2 acute oral toxicity studies as- WoE-2 and WoE-3.
Acute Oral toxicity test was carried out to study the effects of the test chemicals on rodents.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Specific details on test material used for the study:

Name: Hydroxylamine-O-sulphonic acid
InChI: 1S/H3NO4S/c1-5-6(2,3)4/h1H2,(H,2,3,4)
Smiles: O=S(=O)(ON)O
Mol. formula: H3NO4S
Molecular Weight: 113.093 g/mole
Substance Type: Inorganic

Species:

other: 1. rat 2. mouse

Strain:

other: 1. not specified 2. not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

1. not specified
2. not specified

Route of administration:

other: 1. oral: unspecified 2. oral: unspecified

Vehicle:

other: 1. not specified 2. not specified

Details on oral exposure:

1. not specified
2. not specified

Doses:

1. 2000 mg/kg
2. 1100 mg/kg

No. of animals per sex per dose:

1. not specified
2. not specified

Control animals:

not specified

Details on study design:

1. not specified
2. not specified

Statistics:

1. not specified
2. not specified

Preliminary study:

1. not specified
2. not specified

Sex:

not specified

Dose descriptor:

LD50

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Sex:

not specified

Dose descriptor:

LD50

Effect level:

1 100 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

1. 50% mortality was observed at 2000 mg/kg
2. 50% mortality was observed at 1100 mg/kg

Clinical signs:

other: 1. not specified 2. not specified

Gross pathology:

1. not specified
2. not specified

Other findings:

1. not specified
2. not specified

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to CLP regulation the test chemical Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) can be classified as "Category 4 " for acute oral toxicity, as the LD50 value is between 300-2000 mg/kg bw.

Executive summary:

Data available for the structurally similar and closely related read across chemicals has been reviewed to determine the acute oral toxicity of the test chemical Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8). The studies are as mentioned below:

1. Acute oral toxicity study of test chemical was conducted in rat at the concentration of 2000 mg/kg bw. 50% mortality was observed at 2000 mg/kg bw. Therefore, LD50 was considered to be 2000 mg/kg bw, when rats were treated with test chemical via oral route.

2. Acute oral toxicity study of test chemical was conducted in mice at the concentration of 1100 mg/kg bw. 50% mortality was observed at 1100 mg/kg bw. Therefore, LD50 was considered to be 1100 mg/kg bw, when mice were treated with test chemical via oral route.

Thus, based on the above summarised studies, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) and it’s structurally similar and closely related read across substances, it can be concluded that LD50 value is between 300-2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) can be classified as “Category 4” for acute oral toxicity. Hence, Hydroxylamine-O-sulphonic acid is toxic for acute oral toxicity at the dose range of 1100-2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from handbook.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Quality of whole database:

Waiver

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Quality of whole database:

Waiver

Additional information

Acute oral toxicity:

Data available for the structurally similar and closely related read across chemicals has been reviewed to determine the acute oral toxicity of the test chemical Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8). The studies are as mentioned below:

1. Acute oral toxicity study of test chemical was conducted in rat at the concentration of 2000 mg/kg bw. 50% mortality was observed at 2000 mg/kg bw. Therefore, LD50 was considered to be 2000 mg/kg bw, when rats were treated with test chemical via oral route.

2. Acute oral toxicity study of test chemical was conducted in mice at the concentration of 1100 mg/kg bw. 50% mortality was observed at 1100 mg/kg bw. Therefore, LD50 was considered to be 1100 mg/kg bw, when mice were treated with test chemical via oral route.

Thus, based on the above summarised studies, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) and it’s structurally similar and closely related read across substances, it can be concluded that LD50 value is between 300-2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) can be classified as “Category 4” for acute oral toxicity. Hence, Hydroxylamine-O-sulphonic acid is toxic for acute oral toxicity at the dose range of 1100-2000 mg/kg bw.

Acute Inhalation toxicity: 

Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) has very low vapour pressure (1.52E-14 Pa), so the potential for the generation of inhalable vapours is very low. Also the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be highly unlikely and therefore this end point was considered for waiver.

Acute Dermal Toxicity:

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

Based on the above studies on Hydroxylamine-O-sulphonic acid (CAS no.: 2950-43-8) and it’s structurally similar and closely related read across substances, it can be concluded that LD50 value is between 300-2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, Hydroxylamine-O-sulphonic acid can be classified as “Category 4” for acute oral toxicity. For acute inhalation and dermal toxicity wavier were added so, not possible to classify.