Producto P0310

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

other: extrapolation from results obtained by the oral route

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Extrapolation based on available guidelines on route-to-route extrapolation of toxicity data when assessing health risks of chemicals.

Data source

Reference

Reference Type:

other: extrapolation

Title:

Unnamed

Year:

2010

Materials and methods

Principles of method if other than guideline:

Extrapolation based on available guidelines on route-to-route extrapolation of toxicity data when assessing health risks of chemicals.

Test type:

other: extrapolation

Test material

Test material information

Constituent 1

Test material form:

solid

Results and discussion

Effect levels

Key result

Sex:

not specified

Dose descriptor:

LC50

Effect level:

> 10 mg/L air

Exp. duration:

4 h

Any other information on results incl. tables

Based on available guidelines on route-to-route extrapolation of toxicity data when assessing health risks of chemicals, an extrapolation based on the acute oral toxicity data is calculated for the inhalation route.

From the available data on the acute oral toxicity data, it is concluded that the oral LD50 for the substance is greater than 2000 mg/kg bw. As recommended in the corresponding guidelines, where data from the oral route is being used as the starting point, if no data are available on oral bioavailability, it is appropriate to assume that 100% of an orally administered dose is systemically available. Since no data is available on inhalation absorption, the most precautionary default would be to assume 100% absorption by this route.

Based on this acute oral toxicity data, an oral NOAEL may be identified as greater than 2000 mg/kg bw. This NOAEL can be modified into an inhalation NOAEL using a route-to-route extrapolation based on the assumptions stated above. Taking into account an exposure of 4 hours for the acute inhalation toxicity study, the value of 2000 mg/kg bw is divided by the default physiological parameter under the allometric scaling principle which is approximately 0.2 m3/kg bw for rats. This extrapolation leads to a value of 10000 mg/m3 (10 mg/l). Therefore, the 4 -h LC50 would be greater than 10 mg/l (dust/particles inhalation).

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

CLP Implementation.

Conclusions:

Based on the assumptions for the extrapolation from the acute oral toxicity data, the inhalation 4-h LC50 would be greater than 10 mg/l.

Executive summary:

Based on available guidelines on route-to-route extrapolation of toxicity data when assessing health risks of chemicals, an extrapolation based on the acute oral toxicity data is calculated for the inhalation route.

From the available data on the acute oral toxicity data, it is concluded that the oral LD50 for the substance is greater than 2000 mg/kg bw. As recommended in the corresponding guidelines, where data from the oral route is being used as the starting point, if no data are available on oral bioavailability, it is appropriate to assume that 100% of an orally administered dose is systemically available. Since no data is available on inhalation absorption, the most precautionary default would be to assume 100% absorption by this route.

Based on this acute oral toxicity data, an oral NOAEL may be identified as greater than 2000 mg/kg bw. This NOAEL can be modified into an inhalation NOAEL using a route-to-route extrapolation based on the assumptions stated above. Taking into account an exposure of 4 hours for the acute inhalation toxicity study, the value of 2000 mg/kg bw is divided by the default physiological parameter under the allometric scaling principle which is approximately 0.2 m3/kg bw for rats. This extrapolation leads to a value of 10000 mg/m3 (10 mg/l). Therefore, the 4 -h LC50 would be greater than 10 mg/l (dust/particles inhalation).