Dimanganese trioxide

Endpoint summary

Description of key information

No data is available for the target substance dimanganese trioxide. Thus, to assess the potential to induce skin sensitisation of the target substance, available data from manganese oxide (source substance) was used in read-across approach. The source substance was tested negative in an in vivo Local Lymph Node assay conducted in accordance with OECD test guideline 429. Based on this result, the target substance dimanganese trioxide is not considered to be a skin sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For justification of read-across please refer to the read-across statement in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Positive control results:

The Stimulation Index for Phenylacetaldehyde (90%) was considered to be a positive sensitiser under the conditions of the test (see Table 1 in box 'Any other information on results incl. tables').

Key result

Parameter:

SI

Value:

1.21

Test group / Remarks:

2.5% (w/w) in propylene glycol

Key result

Parameter:

SI

Value:

1.31

Test group / Remarks:

5% (w/w) in propylene glycol

Key result

Parameter:

SI

Value:

1.03

Test group / Remarks:

10% (w/w) in propylene glycol

Cellular proliferation data / Observations:

For individual results see Table 2 in box 'Any other information on results incl. tables'.

Table 1: The Stimulation Index (positive control -Phenylacetaldehyde (90%) expressed as the mean radioactive incorporation for the positive control group divided by the mean radioactive incorporation of the vehicle control group

Concentration (% w/w) in Propylene glycol	Stimulation Index	Result
2.5	4.20	Positive

 

Table 2: Disintegrations per minute, disintegrations per minute/node and Stimulation Index

Concentration (% w/w) in propylene glycol	dpm	Dpm/Node^a	Stimulation Index^b	Result
Vehicle	3734.44	466.81	na	na
2.5	4535.63	566.95	1.21	Negative
5	4876.24	609.53	1.31	Negative
10	3853.15	481.64	1.03	Negative

 

dpm = Disintegrations per minute

a = Disintegrations per minute/node obtained by dividing the disintegrations per minute value by 8 (total) number of lymph nodes)

b = Stimulation Index of 3.0 or greater indicates a positive result

na = Not applicable

 

Interpretation of results:

GHS criteria not met

Conclusions:

In a local lymph node assay in mice, manganese oxide was tested negative for skin sensitisation.

Executive summary:

In a dermal sensitisation study according to guideline OECD 429 with manganese oxide (77% Mn content) in propylene glycol, young adult female CBA/Ca mice (4/dose) were tested using the method of the Local Lymph Node Assay. The positive control, Phenylacetaldehyde (90%) in dimethyl formamide (vehicle) produced an increase in the stimulation index (SI) greater than 3 over the control groups. Concentrations of manganese oxide at 2.5, 5 and 10% w/w in propylene glycol did not produce a Stimulation Index greater than 1.31. Due to data showing a Stimulation Index of less than 3 in the study, manganese oxide is not a dermal sensitiser.

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across statement (see IUCLID section 13).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

No data is available for the target substance dimanganese trioxide. Thus, to assess the potential to induce skin sensitisation of the target substance, available data from manganese oxide (source substance) was used in read-across approach. The source substance was tested negative in an in vivo Local Lymph Node assay conducted in accordance with OECD test guideline 429. Based on this result, the target substance dimanganese trioxide is not considered to be a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on available data from a suitable read-across partner, dimanganese trioxide does not warrant classification for skin sensitisation.