2,6-dimethylpyridine

Endpoint summary

Description of key information

Short term toxicity to aquatic invertebrates

The short-term toxicity of the test chemical to aquatic invertebrates was predicted using EPI Suite ECOSAR version 1.11. On the basis of effect of test chemical observed in a static system on the mobility of the test organism during the 48 hr exposure duration, the lethal effect concentration (LC50) for the test chemical was estimated to be 61.0 mg/l. Thus, based on the LC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

The toxicity of the test chemical to green algae was predicted using EPI Suite ECOSAR version 1.11. On the basis of effect of test chemical observed in a static system on the growth rate of the test organism during the 96 hr exposure duration, the median effect concentration (EC50) for the test chemical was estimated to be 43.72 mg/l. Thus, based on the EC50 value, test chemical can be considered as toxic to aquatic algae. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

Additional information

Short term toxicity to aquatic invertebrates

Predicted data of the test chemical and supporting weight of evidence studies for its read across analogue were reviewed for short term toxicity to aquatic invertebrate endpoint which are summarized as below:

 

In a prediction done using EPI Suite ECOSAR version 1.11, the short-term toxicity of the test chemical to aquatic invertebrate was predicted. On the basis of effect of test chemical observed in a static system on the mobility of the test organism during the 48 hr exposure duration, the lethal effect concentration (LC50) for the test chemical was estimated to be 61.0 mg/l. Thus, based on the LC50 value, test chemical can be considered as toxic to aquatic fishes. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic and hence, considered to be ‘not classified’ as per CLP classification criteria.

 

In a supporting weight of evidence study from reliable handbook (2009) and secondary source,an acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical. The study was performed following the principles of the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) and EU Method C.2 (Acute Toxicity for Daphnia), respectively under static conditions. Test was carried out using Daphnia magna (Water flea) as a test organism and under test conditions at temperature of 19.1 to 20.1°C, pH 7.7 to 8.6 and hardness of 198 to 208 mg/l as CaCO3, respectively. Test chemical concentrations were determined analytically. Test chemical concentrations used for the study were 10, 20, 40, 80, 160 and 320 mg/l, respectively (nominal conc.). Mean measured conc. used for the study were 10.3, 20, 41.9, 84, 169.5 and 346.5 mg/l (at 0 hr) and 8.3, 17.1, 34.9, 70.5, 139 and 285 mg/l (at 48 hr), respectively. The results of chemical analysis indicated that intended exposure levels were achieved and adequately maintained during the test. At the lowest test concentration, 9.24 mg/l, 5% immobility was seen after 48 hours. The lowest measured concentration at which 100% immobilisation occurred was 153 mg/l. On the basis of the effect of test chemical on mobility of test organism, the 24 hr and 48 hr median effect concentration (EC50) value was determined to be 83.8 and 39.6 mg/l, respectively. Thus, test chemical can be considered as toxic to aquatic invertebrates. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be ‘not classified’ as per the CLP classification criteria.

 

Another short term toxicity to aquatic invertebrate study was conducted for 48 hrs for assessing the effect of test chemical (J-CHECK). The study was performed in accordance with the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Test was carried out using Daphnia magna (Water flea) as a test organism under static conditions. On the basis of the effect of test chemical on mobility of test organism, the 48 hr median effect concentration (EC50) value was determined to be 34 mg/l. Thus, test chemical can be considered as toxic to aquatic invertebrates. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be ‘not classified’ as per the CLP classification criteria.

 

On the basis of the above results, test chemical can be considered as toxic to aquatic invertebrate. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

Predicted data of the target chemical and supporting weight of evidence studies for its read across analogue were reviewed for toxicity to aquatic algae and cyanobacteria endpoint which are summarized as below:

 

In a prediction done using EPI Suite ECOSAR version 1.11, toxicity to aquatic algae of the test chemical was predicted. On the basis of effect of test chemical observed in a static system on the growth rate of the test organism during the 96 hr exposure duration, the median effect concentration (EC50) for the test chemical was estimated to be 43.72 mg/l. Thus, based on the EC50 value, test chemical can be considered as toxic to aquatic algae. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic and hence, considered to be ‘not classified’ as per CLP classification criteria.

 

In a supporting weight of evidence study from handbook (2009) and secondary source,algal toxicity study was carried out for 72 hrs for assessing the effect of test chemical. The study was performed following the principles of the OECD Guideline 201 (Alga, Growth Inhibition Test).Pseudokirchneriella subcapitata (CCAP no. 278/4) (green algae) was used as a test organism. Test chemical concentrations were determined analytically. Test chemical concentrations used for the study were 1, 3.2, 10, 32 and 100 mg/l (nominal conc.) and 0.689, 2.40, 7.57, 28.1 and 83.0 (geometric mean measured conc.), respectively. Test vessel was loosely plugged with non-porous cotton wool. Study was carried out at a temperature of 22.6 to 23.9°C and pH 7.9 to 9.0, respectively. The intended exposure concentrations were substantially achieved (between 77 and 94% of their nominal values) and adequately maintained during the test (between 80 and 88% of their starting concentrations).Exposure at measured levels of 2.40 mg/l and above resulted in significant reduction in both the specific growth rates and biomass values compared to control cultures (p < 0.05). Thus, the NOEC for both growth rate and biomass was 0.689 mg/l.On the basis of effect growth rate & biomass of the test organism, the 72 hr ErC50 and EbC50 value was determined to be 61.2 & 30.6 mg/l, respectively. Thus, test chemical can be considered as toxic to aquatic algae. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic algae at environmental relevant concentrations and hence, considered to be ‘not classified’ as per the CLP classification criteria.

 

Another toxicity to aquatic algae study was carried out for 72 hrs for assessing the effect of test chemical (authoritative database, 2020). The study was performed following the principles of the OECD Guideline 201 (Alga, Growth Inhibition Test). Study was performed under static conditions. On the basis of effect growth rate & biomass of the test organism, the 72 hrs NOEC value was determined to be 1 mg/l and on the basis of effect growth rate & biomass of the test organism, the 72 hr ErC50 and EC50 value was determined to be >32 & 5.7 mg/l, respectively. Thus, test chemical can be considered as toxic to aquatic algae. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic algae at environmental relevant concentrations and hence, considered to be ‘not classified’ as per the CLP classification criteria.

 

On the basis of the above results, test chemical can be considered as toxic to aquatic algae. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic algae at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

 

On the basis of the available information of aquatic toxicity studies, it can be concluded that the test chemical was considered as toxic to aquatic organismsat environmental relevant concentrations. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.