Reaction mass of calcium dihydroxide and calcium peroxide

Endpoint summary

Description of key information

Based on available data, it might be concluded that the substance is not a skin sensitizer. Thus, it is deemed that further studies on skin sensitization are not scientifically justified.

According to the EU Risk Assessment Report (2003), pg. 114-115, in spite of two reported cases of positive patch tests to hydrogen peroxide and the uncertainty surrounding an outdated animal study (with a negative result), and on recognition of the widespread occupational and consumer use over many decades, it may be confidently stated that the potential of hydrogen peroxide to cause skin sensitisation is extremely low and therefore do not meet the criteria for classification.

Moreover, there is no evidence of any sensitization potential for calcium compounds. Calcium is abundantly available in the environment, in food and extensively distributed throughout the human body. Sensitisation by or intolerance to an abundantly available essential element such as calcium would be grossly implausible and can therefore safely be excluded.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
Based on available data, it might be concluded that the substance is not a skin sensitizer. Thus, it is deemed that further studies on skin sensitization are not scientifically justified.

According to the EU Risk Assessment Report (2003), pg. 114-115, in spite of two reported cases of positive patch tests to hydrogen peroxide and the uncertainty surrounding an outdated animal study (with a negative result), and on recognition of the widespread occupational and consumer use over many decades, it may be confidently stated that the potential of hydrogen peroxide to cause skin sensitisation is extremely low and therefore do not meet the criteria for classification.

Moreover, there is no evidence of any sensitization potential for calcium compounds. Calcium is abundantly available in the environment, in food and extensively distributed throughout the human body. Sensitisation by or intolerance to an abundantly available essential element such as calcium would be grossly implausible and can therefore safely be excluded.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Calcium peroxide when in contact with water, on the one hand hydrolyses into hydrogen peroxide, and on the other hand results in a loss of active oxygen.

 

CaO₂  + H₂O → CaO + H₂O₂

2CaO₂→ 2CaO + O₂

2CaO₂+ 2H₂O → 2Ca²⁺+ 4OH^- + O₂

 

The toxicity of the reaction mass is due to the hydrolysis product hydrogen peroxide (H2O2) and calcium hydroxide (Ca(OH)2). Under physiological conditions, calcium hydroxide ultimately dissociates into calcium cations (Ca2 +) and hydroxyl anions (OH-). Calcium, is an essential and abundantly available mineral nutrient. Hydroxyl anion is neutralised in body fluids.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on available information, the substance is not classified for skin sensitization according to the CLP Regulation (EC) no. 1272/2008.