Reaction product of fusion between 1000°C and 2000°C of aluminium oxide and calcium oxide based raw materials with at least CaO+Al2O3+Fe2O3 > 85%, in which aluminium oxide and calcium oxide in varying amounts are combined in various proportions into a multiphase crystalline matrix.

Endpoint summary

Description of key information

Short description of key information on bioaccumulation potential result: 
Repeated inhalation of aluminium oxide may lead to significant accumulation of Al in the lung. Because of low solubility inhaled aluminium species do not  transfer from the lungs to the systemic circulation at high level. In some extent, translocation to the brain, kidneys and bones are observed.
Short description of key information on absorption rate: 
According to the read-across with the aluminium chlorhydrate, aluminium will not cross the dermal barrier and reach the systemic circulation.

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - dermal (%):

0.01

Additional information

According to the available documents on the solubility of the aluminate cements, the substance, mainly composed of CA and C12A7 phases (where C=CaO, A=Al2O3), rapidly forms inert hydrated phases in water and the main substance found in the aqueous medium at the time of maximum solubility (before recombining) is aluminium hydroxide. Thus it is considered that the only substance that can exert a potential biological activity is aluminium hydroxide.

Repeated inhalation of aluminium oxide may lead to significant accumulation of Al in the lung. Because of low solubility inhaled aluminium species do not transfer from the lungs to the systemic circulation at high level. In some extent, translocation to the brain, kidneys and bones are observed.

According to the read-across with the aluminium chlorhydrate, aluminium will not cross the dermal barrier and reach the systemic circulation.

Discussion on bioaccumulation potential result:

According to Schlesinger (2000), repeated weekly intratracheal instillations of alumina (MMAD=1.2 µm) to Sprague-Dawley rats for 20 weeks at a dose of 1 mg alumina/kg body weight led to significant accumulation of Al in the lung. No significant clearance of Al from the lung occurred during the 19-week post-exposure period. Since no changes in Al levels in extrapulmonary organs of exposed animals were observed over the course of the study, under the experimental conditions the systemic uptake of Al from the lungs does not exceed the clearance capacity of the kidneys. Since Al levels in blood and urine were not measured, the systemic absorption cannot be estimated although the results of the study suggest that uptake was likely to have been low.

According to McAughey (1998) ,the results of this study indicate that, because of low solubility, inhaled aluminium oxide does not effectively transfer from the lungs to the systemic circulation.

According to Rollin (1991), inhalation of Al2O3 eight hours a day five days a week for five months by New Zealand white rabbits led to significant accumulation of Al in the lung, and its translocation to the brain and bone.

Discussion on absorption rate:

According to Flarend (2001), aluminium is absorbed into the systemic circulation on single application with occlusion of aluminium chlorohydrate to underarms. Based on urine measurements, 0.01% of the applied aluminium was absorbed showing that aluminium does not cross the dermal barrier effectively.