Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Acute/short term exposure
DNEL related information

Workers - Hazard for the eyes

Additional information - workers

Acute / short-term exposure - systemic and local effects

- Inhalation:

An acute inhalation toxicity study was performed with zirconium basic carbonate (dust aerosol). The 4-hour LC50 of zirconium basic carbonate was estimated to be greater than 4.74 mg/L for male and female rats. As no adverse systemic effects were observed in the available study up to the maximal technically achievable concentration, no DNEL acute - inhalation (systemic effects) needs to be derived.

Red staining to the snout and jaw in one of three males and one of three females and test substance staining to the snout in one of three males and one of three females were observed immediately after the exposure only. No other local effect was observed. Therefore, no DNEL acute - inhalation (local effects) needs to be derived.

- Dermal:

No acute toxicity study for the dermal route is available for zirconium basic carbonate, however, this study can be waived based on Column 2 adaptation (REACH Regulation, Annex VIII, section 8.5) (acute toxicity data via two routes available). As there are no acute toxicity data available via dermal route for zirconium basic carbonate, no acute/short-term DNEL could be derived. In addition, the dermal route is not the most appropriate route as exposure via inhalation is more likely and there is no indication from the physicochemical properties of significant absorption through the skin (Annex VIII, 8.5.3, Column 2 adaptation).

Long-term exposure - systemic and local effects

- Inhalation:

No long-term inhalation toxicity studies are available for zirconium basic carbonate and this test is also waived based on the following information: reliable information ('weight-of-evidence') is available for the oral route of exposure and, according to the REACH Regulation, only one route of exposure should be tested for repeated dose toxicity (column 2, annex VIII, section 8.6.1). Therefore, it was not necessary to perform a repeated dose toxicity study via the inhalation route of exposure. As there is no adequate data, no DNEL inhalation exposure (systemic effects) is derived. Although experimental data from an oral combined repeated dose toxicity study with reproduction/developmental toxicity screening performed with the read-across substance zirconium acetate are available (Rossiello, 2013), no systemic hazard was identified up to the highest dose tested (limit dose as per OECD 422) that could be used to derive a DNEL using 'route-to-route extrapolation'. Based on all the abovementioned considerations and the fact that there is sufficient evidence available indicating that zirconium is barely absorbed after inhalation exposure to zirconium basic carbonate (see section 7.1), no DNEL long-term (systemic or local effects) needs to be derived.

National exposure limits for zirconium compounds were defined in Europe by 15 national authorities and set at 5 mg/m3 (expressed as Zr). In the USA, NIOSH, ACGIH, and OSHA have evaluated toxicity and defined long-term and short-term exposure limits for zirconium dioxide. The 8-h Time Weighted Average (TWA) was set at 5 mg Zr/m3 whereas the Short Term Exposure Limit (STEL) was set at 10 mg Zr/m3. These values were based on the results of Spiegl et al. (1956) with zirconium dioxide as well as on the results of the study from Hodge (1955). The study of Hodge (1955), is a 1-year experiment performed on rats with zirconium oxide dust at a low dose of 3.5 mg/m3. Unfortunately the unpublished study was not accessible.

Although no DNEL needs to be derived for zirconium basic carbonate, it is advised to respect, when relevant, the currents generic standards for zirconium compounds as mentioned above.

- Dermal:

No long-term dermal toxicity studies are available for zirconium basic carbonate and this test is also waived based on the following information: reliable information is available for the oral route of exposure and, according to the REACH Regulation, only one route of exposure should be tested for repeated dose toxicity (column 2, annex VIII, section 8.6.1). Therefore, it was not necessary to perform a repeated dose toxicity study via the dermal route of exposure. As there is no adequate data, no DNEL dermal exposure (systemic effects) is derived. Although experimental data from an oral combined repeated dose toxicity study with reproduction/developmental toxicity screening performed with the read-across substance zirconium acetate are available (Rossiello, 2013), no systemic hazard was identified up to the highest dose tested (limit dose as per OECD 422) that could be used to derive a DNEL using 'route-to-route extrapolation'. Based on all the abovementioned considerations and the fact that there is sufficient evidence available indicating that zirconium is barely absorbed after dermal exposure to zirconium basic carbonate (see section 7.1), no DNEL long-term (systemic or local effects) needs to be derived.

In addition, the dermal route is not the most appropriate route as exposure via inhalation is more likely and there is no indication from the physicochemical and toxicological properties of significant absorption through the skin (Annex VIII, 8.5.3, column 2 adaptation).

Hazards for the eyes

Based on the data available ('weight-of-evidence' approach), zirconium basic carbonate was concluded not to be classified as hazardous to eyes.

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure
DNEL related information

General Population - Hazard via oral route

Systemic effects

Acute/short term exposure
DNEL related information

General Population - Hazard for the eyes

Additional information - General Population

Acute / short-term exposure - systemic and local effects

- Inhalation:

As no adverse systemic effects were observed in the available study up to the maximal technically achievable concentration, no DNEL acute - inhalation (systemic effects) needs to be derived.

Red staining to the snout and jaw in one of three males and one of three females and test substance staining to the snout in one of three males and one of three females were observed immediately after the exposure only. No other local effect was observed. Therefore, no DNEL acute - inhalation (local effects) needs to be derived.

- Dermal:

No acute toxicity study for the dermal route is available for zirconium basic carbonate, however, this study can be waived based on Column 2 adaptation (REACH Regulation, Annex VIII, section 8.5) (acute toxicity data via two routes available). As there are no acute toxicity data available via dermal route for zirconium basic carbonate, no acute/short-term DNEL could be derived. In addition, the dermal route is not the most appropriate route as exposure via inhalation is more likely and there is no indication from the physicochemical properties of significant absorption through the skin (Annex VIII, 8.5.3, Column 2 adaptation).

- Oral:

Based on available experimental data, there are no acute toxic effects leading to classification and labeling, hence no acute/short-term DNEL needs to be derived.

Long-term exposure - systemic and local effects

- Inhalation:

Based on the available data and the same argumentation as for workers, no long-term DNEL needs to be derived for the general population. In addition, no officially set values are available for the general population.

- Dermal route:

Based on the same argumentation as for workers, no long-term DNEL needs to be derived for the general population.

- Oral route:

Data after repeated oral exposure are available with zirconium basic carbonate and with the read-accross substance zirconium acetate (a 'water soluble' zirconium compound). The assessment of these data ('weight-of-evidence' approach) does not indicate any adverse effects up to the highest (limit) test dose. Therefore, it is not considered necessary to derive a long-term DNEL.

Further argumentation on read-across and the overall extremely low potential of zirconium compounds for causing toxicity is given in the read-across justification attached to Section 13 of IUCLID.

Hazards for the eyes

Based on the data available, ('weight-of-evidence' approach), zirconium basic carbonate was concluded not to be classified as hazardous to eyes.