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Toxicological information

Carcinogenicity

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Description of key information

Calcium (when administered by oral route in food as calcium-lactate) is not carcinogen

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion
Dose descriptor:
NOAEL
850.2 mg/kg bw/day

Additional information

There was no evidence of relevant carcinogenic activity of calcium in both sexes of rats receiving 2.5 or 5 % calcium lactate via drinking water for 104 weeks. The NOAEL for tumour formation in this study is represented by the high dose of 5 %, corresponding to calcium lactate doses of 2150 and 2280 mg/kg bw/d to male and female rats, respectively. This is equivalent to calcium doses of approximately 279.5 and 296.4 mg Ca/kg bw/d for male and female rats. Accordingly, the lower NOAEL value of 279.5 mg Ca/kg bw/d (male rats) is established as a NOAEL for carcinogenicity hazard assessment.

A human clinical study (Baron, 1999; section 7.10.1 of the technical dossier) suggests a beneficial effect of calcium supplementation on cancer risk: Calcium supplementation is associated with a significant – though moderate – reduction of the risk of recurrent colorectal adenomas

 The NOAEL for calcium is 279.5 mg Ca/kg bw/d (male rats) which is therefore used as a basis for deriving an d NOAEL for “Reaction mass of Limestone and dicalcium silicate”.

According to the specification, “Reaction mass of Limestone and dicalcium silicate” contains typically 46% of calcium as oxide equivalent (CaO).

Considering the molecular weight of calcium (40.078 g/mol), and calcium oxide (56.077 g/mol) the content of calcium in “Reaction mass of Limestone and dicalcium silicate” is 32.88 % Ca. “Reaction mass of Limestone and dicalcium silicate” does not contain any main constituents or major impurities that are known to be carcinogenic. The NOAEL for “Reaction mass of Limestone and dicalcium silicate” is obtained by converting the NOAEL for calcium, considering the content of calcium in the substance. The NOAEL is therefore 850.2 mg/kg bw/d.

 

Furthermore, epidemiological data on cement workers (cement used as a surrogate for lime; technical dossier section 7.10.1; Vestbo, 1991) indicate no increased overall cancer risk due to inhalation of cement dust in this population.

The following information is taken into account for any hazard / risk assessment:

Calcium (when administered orally in feed as Ca -lactate) is not carcinogenic.

The NOAEL of “Reaction mass of Limestone and dicalcium silicate”, converted from Ca taking into account the respective molecular weights, has been determined at 850.2 mg/kg bw/d.

Justification for classification or non-classification

No increased rate of tumour formation was observed in studies on calcium lactate in rats. “Reaction mass of Limestone and dicalcium silicate” does not contain any main constituents or major impurities that are known to be carcinogenic. Calcium, and in consequence “Reaction mass of Limestone and dicalcium silicate” is not considered to be carcinogenic. Classification for carcinogenicity is not applied.