3-methylpyridine

Endpoint summary

Description of key information

non-sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

existing in vivo data which predates adoption of REACH and its supplemental regulations

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Information comes from a submission of a collection of acute toxicity data to the U.S. EPA, and provides little documentation. The studies use older protocols using guinea pigs; they predate the adoption of the REACH legislation and the development of the LLNA and in vitro methods.

Qualifier:

no guideline available

Principles of method if other than guideline:

Precedes establishment of guideline and GLP. It is assumed that this scientific study was performed according to the accepted standards of its day.

GLP compliance:

no

Type of study:

other: guinea pig

Justification for non-LLNA method:

The studies use older protocols using guinea pigs; they predate the adoption of the REACH legislation and the development of the LLNA and in vitro methods.

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

No. with + reactions:

0

Total no. in group:

3

Remarks on result:

no indication of skin sensitisation

Remarks:

Assume 0 sensitised of at least 3 animals at 24 h reading

Not sensitising in guinea pigs.

As dermal irritation and toxicity of pyridine in guinea pigs was well studied and reported, it is anticipated that the dosage was appropriately chosen for this sensitisation study.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

The dermal sensitisation properties of the category substance pyridine were studied in the guinea pig, and pyridine was found to be a non-sensitiser. This read-across approach is valid for the purposes of classification and labelling, and for risk assessment. Additionally, appropriate risk management measures for a corrosive substance are protective of workers.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

3 -Methylpyridine was evaluated in a weight of evidence approach to sensitisation, relying on a category member, pyridine (CAS 110 -86 -3). Pyridine was found in a reputable industry laboratory to be non-sensitising in guinea pigs (Anonymous, Eastman Kodak Company, 1978. Pyridine was included in the validation data set for the ICCVAM Local Lymph Node Assay, and was found to be a weak sensitiser. The authors of the ICCVAM study noted that this positive result was unexpected, and may be due to high experimental doses associated with irritation. There is little human evidence that pyridine is a sensitiser.  In accordance with the harmonized classifications of three of the category members according to Regulation (EC) No. 1272/2008, Annex VI, Indices # 613-002-00-7, 613 -036 -00 -2 (2 -methylpyridine) and 613 -037 -00 -8 (4 -methylpyridine), the registered substance, 3 -methylpyridine, is not classified as a dermal sensitiser.

Migrated from Short description of key information:
This substance is judged by a weight of evidence approach to be non-sensitising to the skin.

Justification for selection of skin sensitisation endpoint:
Experimental results on a read-across substance

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No data available

Migrated from Short description of key information:
There is no evidence of respiratory sensitisation.

Justification for classification or non-classification

Using data from a structurally similar substance in a chemical category, sensitisation was evaluated for 3 -methylpridine. The analogue, pyridine, is not sensitising in the guinea pig, nor has human experience demonstrated sensitisation in manufacturing plant workers. A local lymph node assay showed a weak positive which was unexpected to the authors, but this may be due to doses higher than usual. In the absence of firm data to the contrary, pyridine is a non-sensitiser.

There are harmonized classifications for three of the four members of the Pyidine and Pyridine Derivatives Category. In Regulation (EC) No. 1272/2008, Annex VI, none of the category members are classified as sensitisers: Pyridine (Index #613-002-00-7, 2-methylpyridine (Index # 613-036-00-2) and 4-methylpyridine (Index # 613-037-00-8).  Similarly, we evaluate 3 -methylpyridine to be a non-sensitiser.

3 -Methylpyridine is corrosive to the skin and eyes. Risk managment measures are indicated for corrosion which will minimize skin contact and be sufficiently protective of workers regarding sensitisation.