Reaction mass of calcium carbonate and calcium dihydroxide and silicon dioxide

Endpoint summary

Description of key information

Instead of conducting new in vivo tests, available data on the constituents of the reaction mass of calcium carbonate, calcium dihydroxide and silicon dioxide were used to evaluate the acute toxic potential of the substance. The available data indicate that the substance is not acutely toxic or harmful via oral, dermal or inhalation route.

Additional information

Instead of conducting new in vivo tests, available data on the constituents of the reaction mass of calcium carbonate, calcium dihydroxide and silicon dioxide were used to evaluate the acute toxic potential of the substance. The available data indicate that the substance is not acutely toxic or harmful via oral, dermal or inhalation route. Acute effects related to the systemic activity of any constituent(s) are not expected, because they all are inorganic salts which have a low solubility in water and thus low bioavailability or which dissociate in ions which are efficiently regulated in the human body, i.e.OH^-and Ca2⁺.

 

Possible acute effects are local effects and associated to the irritation/corrosion potential of the substance, , mainly related to its alkalinity (calcium dihydroxide).

Considering the existing knowledge on the (constituents of the) reaction mass of calcium carbonate, calcium dihydroxide and silicon dioxide, no new studies are considered justified.

 

Information sources:

European chemical Substances Information System http://ecb.jrc.ec.europa.eu/esis/

International Programme on Chemical Safety, Concise international chemical assessment document No.24, Crystalline silica, Quartz, 09-21-10, http://www.inchem.org/documents/cicads/cicads/cicad24.htm

International chemical Safety Cards, National Instutute for occupational Safety and Health http://www.cdc.gov/niosh/ipcsneng/neng0808.html

International chemical Safety Cards, National Instutute for occupational Safety and Health http://www.cdc.gov/niosh/ipcsneng/neng0408.html

International chemical Safety Cards, National Instutute for occupational Safety and Health 

http://www.cdc.gov/niosh/ipcsneng/neng0409.html

Recommendation from the Scientific Committee on Occupational Exposure Limits for Calcium oxide (CaO) and Calcium Hydroxide (Ca(OH)2), European Commission, DG Employment, social Affairs and Equal Opportunities, SCOEL/SUM/137, February 2008

Threshold Limit Values & Biological Exposure Indices for Chemical Substances and Physical Agents, ACGIH®, Signature Publications, 2010 

Justification for classification or non-classification

Instead of conducting new in vivo tests, available data on the constituents of the reaction mass of calcium carbonate, calcium dihydroxide and silicon dioxide were used to evaluate the acute toxic potential of the substance. The available data indicate that the substance is not acutely toxic or harmful via oral, dermal or inhalation route. Acute effects related to the systemic activity of any constituent(s) are not expected, because they all are inorganic salts which have a low solubility in water and thus low bioavailability or which dissociate in ions which are efficiently regulated in the human body, i.e. OH^-and Ca2⁺. Therefore classification for acute toxicity is not considered necessary

 

Possible acute effects are local effects and associated to the irritation/corrosion potential of the substance, , mainly related to its alkalinity (calcium dihydroxide). This latter hazard associated to calcium hydroxide (typical concentration in substance being 40%) is considered sufficient to trigger a classification of the reaction mass of calcium carbonate, calcium hydroxide and silicon dioxide as STOT SE 3 (H335 – May cause respiratory irritation).