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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Link to relevant study record(s)

Description of key information

The EC50 for freshwater invertebrates represents the 48-hour EC50 reported by Weytjens and Wils (1991) on Daphnia magna, in accordance with OECD Guideline 202, compliant with GLP.  This LC50 was the key value for short-term toxicity to aquatic invertebrates for all chemicals in the category (i.e., pyridine, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine).  The 24-hour EC50 of 221.4 mg 2-methylpyridine/L (nominal concentration) on Daphnia magna reported by Eisentraeger et al. in a supporting study (2008) is similar to the value reported by Weytens and Wils (1991).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
320 mg/L

Additional information

The point of departure for the derivation of the PNECaquaticwas the EC50 value from the 72-hour Selenastrum capricornutum (aquatic alga) assay and the EC50 value from the 48-hour Daphnia magna (aquatic invertebrate) conducted by Weytjens and Wils (1991) on 3-methylpyridine; these two EC50 values (which were equivalent) represented the lowest of the short-term toxicity values from the key study for each of three trophic levels (fish, aquatic invertebrates and aquatic algae), and were selected as the point of departure for the derivation of the PNECaquatic for the chemical category including pyridine, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine. 

2-Methylpyridine (alpha-picoline, CAS 109-06-8) is a member of a category with is utilized for “read-across” to fill data gaps and for risk assessment for hazard identification. The category of pyridine and alkyl pyridine derivatives is comprised of pyridine (CAS 110 -86 -1), 2-methylpyridine (CAS 109-06-8), 3-methylpyridine (CAS 108-99-6) and 4-methylpyridine (CAS 108-89-4). The foundation of the category is a common functional group (the pyridine unsaturated ring structure) and similar physico-chemical properties, environmental fate and toxicity, and mammalian toxicity. Similar ecotoxicological and environmental fate properties derive from physico-chemical parameters and common pathways of metabolism and elimination among all members of the category. Three of four members of this category have harmonized classification and labelling. Read-across for non-harmonized endpoints is adequate for risk assessment purposes.