Sodium N-chlorobenzenesulphonamide

Endpoint summary

Description of key information

Key studies were available for acute oral and dermal toxicity testing with Chloramine B trihydrate. Acute Toxic Class oral testing in female rats resulted in LD50 between 300 mg/kg bw (no animals died) and 2000 mg/kg bw (all animals died). At 300 mg/kg bw, very mild clinical signs of intoxication (erected hair, hunched posture) were seen in 3 animals and liver dystrophy was seen at pathology in 3 other animals. Acute inhalation toxicity testing was waived based on low vapour pressure and large particle size.  Acute dermal toxicity testing in rats resulted in LD50>2000 mg/kg bw. No clinical signs of toxicity were observed during the study, except for symptoms of skin irritation which were almost healed. Macroscopic changes included skin crusts and granular surface of the spleen in all animals. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 150 mg/kg bw

Quality of whole database:

High quality study

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

High quality study

Additional information

In a key oral toxicity study (Dvorakova, 2006a), Chloramine B trihydrate was administered by gavage in a single dose as solution in water for injection to three groups of three female Wistar rats: group No. 1 (first step) 2000 mg/kg bw, group No. 2 (second step) 300 mg/kg bw and group No. 3 (third step) 300 mg/kg bw. The test substance administered at the dose of 2000 mg/kg bw caused death of all three animals, clinical signs of intoxication were observed in all three animals and macroscopic changes were diagnosed during pathological examination in all three animals. The test substance administered at the dose of 300 mg/kg bw caused no death in females, very mild clinical signs of intoxication were observed in three animals (erected hair, hunched posture) and macroscopic changes were diagnosed during pathological examination in three females. According to the study results the value of LD50 of the test substance Chloramin B for rats is in the range >300 mg/kg bw to ≤ 2000 mg/kg bw. The exact value was not given in the report, but can be considered to be around 1150 mg/kg bw.

No acute inhalation toxicity data or studies directly for Chloramine B (Sodium N-chlorobenzenesulphonamide trihydrate) are available. Chloramine B trihydrate has a very low vapour pressure ranging between 1536 Pa (20°C) and 1976 Pa (25°C), whereas Chloramine B showed a very low vapour pressure value (2.44 x 10-9Pa ). Further, particle size distribution in the tested sample of Chloramine B shows that only 1 % of particles are less than 100 μm in diameter, thus Chloramine B practically cannot penetrate in the alveolar region of the lungs.

More information is provided in waiver documentation, attached to Section 13.

A key acute dermal toxicity study (Dvorakova, 2006b) was performed as limit test: two groups of animals (5 males and 5 females) at the dose of 2000 mg/kg bw. The test substance was applied occlusively on the shaved skin of the test animals moistened with the smallest amount of water for 24 hours.The test substance applied in dose 2000 mg/kg bw did not cause death of animals. No clinical signs of toxicity were observed during the study in all animals, except for symptoms of skin irritation which were almost healed. Macroscopic changes were diagnosed during pathological examination in all animals (skin: crusts; spleen: granular surface). According to the study results the value of LD₅₀ dermal of the test substance Chloramin B trihydrate for rats of both sexes is higher than 2000 mg/kg bw.

 

 

Justification for selection of acute toxicity – oral endpoint
Key study

Justification for selection of acute toxicity – dermal endpoint
Key study

Justification for classification or non-classification

Chloramine B trihydrate needs to be classified for oral acute toxicity according to the Directive 67/548/EEC, Annex VI. as harmful and assigned the symbol Xn and the indication of danger “harmful”; the following risk phrase shall be assigned: R22 -Harmful if swallowed. For the acute dermal toxicity, Chloramine B trihydrate did not fall into any categories of toxicity and has no obligatory labelling requirement.

According to CLP regulation (No. 1272/2008 of 16 December 2008), Chloramine B trihydrate is classified as Category 4 for acute oral toxicity, with signal word "harmful" and hazard statement: H302- Harmful if swallowed. For the acute dermal toxicity, Chloramine B trihydrate did not fall into any categories of toxicity and has no obligatory labelling requirement.