N,N-dimethyl-p-toluidine

Endpoint summary

Additional information

Short term toxicity to fish:

Based on the various studies available with Klimish rating 2 for the target substance CAS NO 99-97-8 The results is summarized as follows

Sr.No	Endpoint	Effect values	Basis for effects	Duration	Species	Remarks
1	TLm	44 mg/l	mortality	24 hrs	Oryzias latipes	Data from publication for target chemical
2	TLm	20 mg/l	mortality	24 hrs	Oryzias latipes	Data from publication for target chemical
3	LC50	52.8 mg/l	mortality	96hrs	Pimephales promelas	Data from publication for target chemical
4	LC50 EC50	52 mg/l 52 mg/l	mortality	96hrs	Pimephales promelas	Data from publication for target chemical
3	LC50 EC50	46 mg/l 41.5 mg/l	mortality	96hrs	Pimephales promelas	Data from publication for target chemical

 

By applying weight of evidence approach to the studies summarized in the above table it can be observed that the LC50 values was found to be in range of 46 to 52 mg/l in 96 hrs and the EC50 values was found to be in the range of 41.5 to 52 mg/l in 96 hrs. Also the Median Tolerence limit (TLm) value was found to be in the range of 20 to 44 mg/l in 24 hrs study on the basis of mortality effect. Since the substance was not found to be rapidly degradable. Thus considering the CLP Criteria for aquatic classification of the substance, it is concluded that N,N-dimethyl-p-toluidine exhibit short term toxicity to fish (Oryzias latipes,Pimephales promelas) in aquatic chronic category 3.

Long term toxicity to fish:

According to column 1 of Annex IX , long-term toxicity testing on fish was considered for waiver as short term toxicity data has already been provided as part of Annex VIII requirements in section 6.1.1 of this dossier

Short term toxicity to aquatic invertebrate:

Based on the various studies available with Klimish rating 2 and 4 for target chemical CAS NO 99-97-5 and the read across substances . The results is summarized as follows

 

Sr.No	Endpoint	Effect values	Basis for effects	Duration	Species	Remarks
1	LC50	15.259 mg/l	mortality	48 hrs	Daphnia magna	Predicted data for target chemical
2	EC50	23.758 mg/L.	mortality	48 hrs	Daphnia magna	Data from database
3	EC50	13.7 mg/L.	mortality	48 hrs	Daphnia magna	Data from publication for CAS no 121-69-7

 

By applying weight of evidence approach to the studies summarized in the above table, the EC50 value is expected to be in range of 13.7 to 23.758 mg/l and LC50 value was found to be 15.259 mg/l in 48 hrs study on the basis of mortality effect. Since N,N-dimethyl-p-toluidine is not found to be rapidly degradable. Thus according to CLP criteria of aquatic classification it is concluded that the substance N,N-dimethyl-p-toluidine is toxic to aquatic invertebrate (Daphnia magna)in aquatic chronic category 3

Long term toxicity to aquatic invertebrate:

According to column 1 of Annex IX , long-term toxicity testing on aquatic invertebrates was considered for waiver as short term toxicity data has already been provided as part of Annex VII requirements in section 6.1.3 of this dossier.

Toxicity to aquatic algae and cynobacteria:

Based on the various studies available with Klimish rating 2 and 4 for the target substance CAS NO 99-97-8 and read across substances and based on the category approach of organic functional group along with similar mechanistic approach and having structural similarities defined by QSAR toolbox. The results is summarized as follows

 

Sr.No	Endpoint	Effect values	Basis for effects	Duration	Species	Remarks
1	EC50	15.481  mg/l	growth rate	96 hrs hrs	Green algae	Data is from database
2	EC50	24.37mg/l	Growth	72 hrs	Pseudokirchneriella subcapitata	Predicted data of target chemcial
3	EC50	22 mg/l	growth rate	72 hrs	Chlorella pyrenoidosa	Data from publication for CAS no 121-69-7

 

By applying weight of evidence approach to the studies summarized in the above table it can be observed that EC50 value is expected to be in range of15.481 to24.37 mg/l in 72 hrs to 96 hrs study on the basis of growth rate. Sincesubstance was not found to be rapidly degradable.Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that N,N-dimethyl-p-toluidine does exhibit toxicity to (green algae, Pseudokirchnerella subcapitata, Chlorella pyrenoidosa) in aquatic chronic category 3

Toxicity to microorganism:

Based on the various studies available with Klimish rating 2 and 4 for the target substance CAS NO 99-97-8 and read across substances and based on the category approach of organic functional group along with similar mechanistic approach and having structural similarities defined by QSAR toolbox. The results is summarized as follows

 

Sr.No	Endpoint	Effect values	Basis for effects	Duration	Species	Remarks
1	IGC50	80.53 mg/l	growth inhibition	48 hrs	Tetrahymena pyriformis	Predicted data for target chemical
2	EC50	161.2  mg/l	growth inhibition	24 hrs	Tetrahymena pyriformis	Predicted data for target chemical
3	EC50	42.86  mg/l	growth inhibition	48 hrs	Tetrahymena pyriformis	Predicted data for target chemical
4	IGC50	32.6 mg/l	growth inhibition	48 hrs	Tetrahymena pyriformis	Data from publication for CAS no 91-66-7
5	EC50	13.6 mg/L	reduction in light emission	30 min	Photobacterium phosphoreum	Data from publication for CAS no 121-69-7

 

By applying weight of evidence approach to the studies summarized in the above table it can be observed that EC50 value is expected to be in the range of 13.6 to 161.2 mg/l based on the growth inhibition effect for various duration starting from 30 mins till 48 hours.