Methyl nicotinate

Endpoint summary

Description of key information

Short-term toxicity to fish

Fish Acute Toxicity test according to OECD Guideline 203 was conducted for (test item name) Methyl nicotinate The nominal concentration selected for the experiment were 100 mg/Land test fish were exposed to these concentration for 96 hours. The lethal concentrations LC50 was found to be >100 mg/L since no mortality was observed during the experiment.

 

Short term toxicity to aquatic invertebrates

The median effective concentration (EC50) for the test substance Methyl nicotinate (CAS No: 93-60-7), in Daphnia magna was determined to be 189.2 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the median effective concentration value, it is concluded that the substance is likely to be non-hazardous to aquatic invertebrates and cannot be classified as per the CLP criteria.

 

 

Toxicity to aquatic algae and cyanobacteria

After 72 hours of exposure to test item Methyl nicotinate (CAS No: 93-60-7) to various nominal test concentrations, EC50 was determine to be 130.82 mg/l graphically and through probit analysis. Based on the EC50, it can be concluded that the chemical was non- toxic and cannot be classified as per the CLP criteria.

Additional information

Short-term toxicity to fish

Four studies including those from experimental study and validated prediction for short term fish toxicity endpoint of target chemical Methyl nicotinate (Cas no. 93-60-7) with relevant read across which is structurally similar to target were summarized as followed: 

 

First experimental key study by UERL laboratory; 2017 suggest the Fish Acute Toxicity test according to OECD Guideline 203 was conducted for Methyl nicotinate, The nominal concentration selected for the experiment were 100mg/Land test fish were exposed to these concentration for 96 hours. The lethal concentrations LC50 was found to be >100 mg/L since no mortality was observed at 100 mg/l in 96 hrs exposure period.

 

Above aquatic classification is supported by prediction for target, from EPI Suite ECOSAR version 1.10 wherein the 96 hours LC50 was estimated to be 1876.926 mg/l on Fish on the basis of mortality effects using neutral organics class for prediction. Based on this value, it can be concluded that the test chemical Methyl nicotinate can be considered as non toxic to fish at mentioned predicted lethal concentration thus it can be considered not classified as per the CLP classification criteria.

 

Another predicted result from Danish QSAR database reported the 96 hrs LC50 value by three different models i.e, Battery, Leadscope and SciQSAR, used within the database, to be 168.31 mg/l for test chemical Methyl nicotinate.

 

All the above studies for target chemical are further supported by read across Nicotinic acid (Cas no. 59-67-6). Acute fish toxicity according to OECD Guideline 203 was conducted for chemical Nicotinic acid (Cas no. 59-67-6). According to toxicity study the median lethal concentration (LC50) for 96 hrs.exposure period was observed to be 520 mg/l on fish species Brown trout (Salmo trutta) (Screening Information Data Set (SIDS) of OECD High Production Volume Chemicals Programme, (1993))

 

Thus based on all available studies for target and read across chemical gives the lethal concentration is in the range of 100-1876.926 mg/l concluded that the test Methyl nicotinate (Cas no. 93-60-7) considered as non-toxic to fish at environmentally relevent concentrations and thus cannot be classified as hazardous as per the CLP criteria.

 

Short term toxicity to aquatic invertebrates

Aim of this study was to assess the short term toxicity of Methyl nicotinate (CAS No: 93-60-7) to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs. The stock solution 10mg/l was prepared by dissolving white powder in reconstituted water. The test solutions of required concentrations were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 50, 70,100,140 and 200 mg/L mg/L nominal concentrations were used in the study. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0.The median effective concentration (EC50) for the test substance Methyl nicotinate (CAS No: 93-60-7), in Daphnia magna was determined to be 189.2 mg/L on the basis of mobiity inhibition effects in a 48 hour study. Based on the median effective concentration value, it is concluded that the substance is likely to be non-hazardous to aquatic invertebrates and cannot be classified as per the CLP criteria.

In a similar study,Daphnia sp., Acute Immobilization Test according to OECD Guideline 203 was conducted for Methyl nicotinate(CAS No. 93-60-7).

The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 10 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 100 mg/L, respectively.

The nominal concentration selected for the experiment was 100 mg/l- and test Daphnia magna were exposed to these concentration for 48 hours. The median lethal concentration (EC50) for Methyl nicotinate(CAS No. 93-60-7) on Daphnia magna in a 48 hours study on the basis of immobilization effect was observed to be >100 mg/l.Thus, on the basis of this EC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, Methyl nicotinate(CAS No. 93-60-7) does not exhibit short term toxicity to Daphnia.

EC50 (48 hours) Experimental is >100 mg/l.After 48 hours of exposure to test item Methyl nicotinate(CAS No. 93-60-7) to various nominal test concentrations, EC50 was determine to be >100 mg/l . Based on the EC50, it can be consider that the chemical was non hazardous and can be consider to be not classified as per the CLP classification criteria.

From above summarized studies it can be concluded that the test chemical can be classified as 'Not classified' according to CLP criteria.

 

Toxicity to aquatic algae and cyanobacteria

The study was designed to assess the toxic effects of the test compound Methyl nicotinate (CAS No: 93-60-7) on the green alga Chlorella vulgaris. Test was conducted in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test).

 

Test was carried out in 100mL conical flasks which were carefully autoclaved and sterilized. The test solution in each of these test vessels was kept constant which is 60 ml so that a sufficient amount of head space was left.

The test solution was prepared in aseptic condition. The test item Methyl nicotinate (CAS No: 93-60-7) was prepared by adding 50mg of test item in 250 ml of BBM to get the final concentration of 200 mg/L. This stock solution was kept for stirring for 01 minutes to obtain a homogenous solution for the experiment. The test concentrations were chosen according to the available data of the test item. The concentrations chosen were set up to the water solubility limit. The remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 104cells/ml. Care was taken to have a homogeneous solution for the experiment.

 

For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined.

Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. For microscopic observations the cultures were observed daily with the help of a microscope to verify a normal and healthy appearance of the algal culture and also to observe any abnormal appearance of the algae (as may be caused by the exposure of the test item). Apart from this, the cell count of each test vessel was also noted with the help of a microscope and haemocytometer. By spectrophotometer the absorbance values of each test vessel and control vessel was noted at 680nm.The BBM was taken as blank for both control and test vessels. The absorbance value of each vessel was in line with the average specific growth rate.

 

As per OECD 201, the biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72 hr test period. This corresponds to a specific growth rate of 0.92 per day. Thus, the observed specific growth rate in the control cultures during the experiment was 0.264 per day. The mean coefficient of variation for section by section specific growth rates (days 0-1, 1-2 & 2-3, for 72 hr tests) in the control cultures must not exceed 35%. Thus, the observed mean coefficient of variation in the control cultures during the experiment was 20.24%. The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 10%. Thus, the observed coefficient of variation of average specific growth rates during the experiment in control cultures was 9.31%. Hence, the test is considered valid as per OECD guideline, 201

After 72 hours of exposure to test item Methyl nicotinate (CAS No: 93-60-7) to various nominal test concentrations, EC50 was determine to be 130.82 mg/l graphically and through probit analysis. Based on the EC50, it can be concluded that the chemical was non- toxic and cannot be classified as per the CLP criteria.