Reaction mass of aluminium and aluminium oxide and calcium oxide and magnesium oxide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Human Studies

One small study of relatively weak design (Hosovski et al. 1998) observed higher rates of skin hypersensitivity, increased aluminium dermal responsiveness and increased serum IgA and IgG levels among aluminium smelter workers compared with an “unexposed” control group. Thomas et al. (2003) found no positive patch-test reactions to ceramic alumina disks in a sample of 251 consecutive cases visiting a dermatology clinic. Although limited in amount, the evidence from human studies supports a low sensitisation potential for aluminium oxide on dermal exposure.

 

Animal Studies

Results from the non-guideline compliant study (based on the Landsteiner/Draize test) on the sensitisation potential of aluminium oxide (Degussa AG, 1979)indicate that aluminium oxide is not a skin sensitizer. Results from studies of the dermal irritation properties of aluminium oxide (Degussa AG, 1977; IUCLID, 2000) support a low sensitisation potential for this substance.Data on the physico-chemical characteristics of aluminium oxide and toxicokinetics, and evidence from sufficiently valid results for a closely related compound (aluminium hydroxide, LAB Research Ltd., 2010) and more bioavailable aluminium compounds (aluminium chloride hexahydrate, Basketter et al., 1999; aluminium chloride, Magnusson and Kligman, 1969) support this evaluation. The evidence from animal studies supports a low sensitisation potential for aluminium oxide on dermal exposure.

Overall, the weight of evidence supports a low sensitisation potential for aluminium oxide.

Based on the available data (Degussa AG, 1979), aluminium oxide does not require classification as a skin sensitizer.

 

Migrated from Short description of key information:
Non-guideline compliant study (based on the Landsteiner/Draize test) on the sensitisation potential of aluminium oxide (Degussa AG, 1979) indicate that aluminium oxide is not a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Based on an assessment of the available data, the weight of evidence does not support an important role for alumina in the development of potroom asthma. The weight of evidence supports an irritative effect of the fluoride component of pot emissions (Taiwo et al., 2006; Søyseth et al., 1992, 1994, 1997; Sorgdrager et al., 1998; Kongerud and Samuelsen, 1991). Work-related asthmatic symptoms in potroom workers may result, in part, from non-specific “irritant” and also from “allergic inflammation” reactions (Sariҫ et al., 1986; Mackay et al., 1990; Eklund et al., 1989). The relative contributions of these mechanisms are unclear and individuals with pre-existing bronchial hyper-responsiveness or a history of respiratory allergy may be at increased risk (Barnard et al., 2004; Kongerud and Samuelsen, 1991).

Some studies among aluminium welders have shown decrements in lung function (Fishwick et al., 2004; Abbate et al., 2003; Nielsen et al., 1993) and others have not (Sjogren and Ulfvarson, 1985; Kilburn et al., 1989). Sjogren and Ulfvarson (1985) observed an association between respiratory symptoms and exposures to ozone among welders. The small sample sizes, questionable comparability of referent groups (e.g. Kilburn et al., 1989) and possible (residual) confounding by smoking and irritative co-exposures such as ozone and other fume constituents are limitations of the available studies.

Results from a few case reports, notably Vandenplas et al. (1998) (also Park et al.,1996 and Burge et al., 2000) indicate that respiratory sensitization on exposure to poorly soluble aluminium substances can occur, but results from larger studies (Fritschi et al., 2001; Beach et al., 2001; Taiwo et al., 2006) suggest that it is rare. 

The only animal study identified that employed a guideline assay with results relevant to the respiratory sensitization endpoint and the target substances (the LLNA; Basketter et al., 1999) found that aluminium chloride, a more soluble aluminium substance, did not possess “significant ability to sensitize the skin”. As discussed by ECHA (2008):“In combination with other data it might be possible to conclude in a WoE assessment that chemicals that (at an appropriate test concentration and test conditions, i.e. skin penetration should have occurred) are negative in the LLNA, as well as being considered as not being skin sensitizers, can also be regarded as lacking the potential to cause allergic sensitisation of the respiratory tract.” (ECHA, 2008). The mouse study of Ichinose et al. (2008) supports a weak allergic inflammatory potential for Al₂O₃. In addition, the guideline compliant study by Lab Research Ltd. (2010) that tested the skin sensitisation potential of Al(OH)₃reported negative results, thereby contributing to the weight of evidence supporting a low sensitizing potential for the poorly soluble target substances (See the companion RSI hazard assessment report on skin sensitisation, HAR_skin_sensit_100831_FINAL.doc).

 

Migrated from Short description of key information:
Based on a weight of evidence argument, aluminium oxide does not require classification as a respiratory sensitizer.

Justification for classification or non-classification

The current weight of evidence supports a low skin and respiratory sensitizing potential for the poorly soluble substance aluminium oxide.

Overall, according toDSD (67/548/EEC) or CLP (1272/2008/EC) classification criteria for sensitisation, no classification is required.