2-methyl-m-phenylene diisocyanate

Endpoint summary

Additional information

Short-term toxicity to fish:

Static 96 h toxicity tests were performed with one freshwater species Pimephales promelas (Fathead minnow)to determine influenced to aquatic toxicities.

For analytical analysis Model 2100 gas chromatograph equipped with electron capture detector and column of 3~ SE-30 on 100/120 Vataport 30 was used.and deionized water or acetone used as a vehicle.LC50's and confidence intervals were determined by either probit analysis (Finney, 1971; Barr et al., 1976), moving average method, or the binomial test (Stephan, 1977), depending on the number of partial kills observed. Each confidence interval describes the distribution of sensitivities of the test organisms: it does not indicate the precision of the acute mortality test.

LC50's and confidence intervals were determined by either probit analysis (Finney, 1971; Barr et al., 1976), moving average method, or the binomial test (Stephan, 1977), depending on the number of partial kills observed. Each confidence interval describes the distribution of sensitivities of the test organisms: it does not indicate the precision of the acute mortality test.

From experimetal result ot is concluded that the Toluene-2,4-diisocyanate was not found to be hazardous to freshwater fish Pimephales promelas with lethal concentration (LC50)195 mg/L for 24 hr; 172 mg/L for 48 hr; 164 mg/L for exposure period 96 hrs.

Short term toxicity to aquatic inveretbrates:

Various predicted studies for the2,6-Toluene diisocyanate (91-08-7) and read across were reviewed to summarize the following information: 

48 hrs aquatic toxicity studies (SSS QSAR prediction model, 2016) were conducted to assess toxic effects of2, 6-Toluene diisocyanate (91-08-7) and the results were predicted. The study was based on the effects of the test compound on the Daphnia magna in a static fresh water system. The predicted data suggests the effective concentration (EC50) for the2, 6-Toluene diisocyanate (91-08-7)wasestimated to be 33.382987976 mg/Lon the basis of intoxication at 20 degree C. As per the CLP regulation, based on the result, 2,6-Toluene diisocyanate (91-08-7) was considered to be likely to be hazardous to aquatic invertebrates, hence the 2,6-Toluene diisocyanate (91-08-7) was considered to be classified in aquatic chronic category 3.

 

Short term toxicity to aquatic invertebrates test using read across chemical m–tolylidene diisocyanate was performed (Iuclid dataset, EUROPEAN COMMISSION – European Chemicals Bureau, 2000) in Daphnia magna for 48 hrs in static condition at 25 degree C with pH 7.5. Test material stirred into well water, at the desired concentration, for 24 hour prior of the daphnids. At the time of the test, the medium was analysed for toluene diamines (TDA), dissolved organic carbon, pH and oxygen content. Test conducted at initial pH 7.5, and repeated at initial pH 6 and 9.EC 0, EC 50 and EC 100 value for m-Tolylidene diisocyanate (26471-62-5) was determined to be 1.6, 12.5 and 100 mg/l for short term toxicity to aquatic inveretbrates.

For same read across chemical short term toxicity to aquatic invertebrates test was performed (Iuclid dataset, EUROPEAN COMMISSION – European Chemicals Bureau, 2000) in Mysidopsis bahia for 48 hrs in static condition at 25 degree C with pH 7.6 and photoperiod of 14 hrs. Test material stirred into a mixture of sea water and well water, at the desired concentration, for 24 hour prior to test. Static conditions were used for at pH 7.6 with 14 hrs photoperiod. Initial and final concentrations of toluene diamines, dissolved organic carbon, dissolved oxygen, and pH, were measured.EC 0, EC 50 and EC 100 value for m-Tolylidene diisocyanate (26471-62-5) was determined to be 6.25, 18.3 and 50 mg/l for short term toxicity to aquatic invertebrates.

Another study on read across chemical Isophorone diisocyanate (4098-71-9) for short term toxicity to aquatic invertebrates test was performed in Daphnia magna for 24 hrs in static condition. Based on the result, Isophorone diisocyanate (4098-71-9) was considered likely to be toxic to aquatic invertebrates and classified in aquatic chronic 3 category as per the CLP regulations.

On the basis of results for toxicity to aquatic invertebrates from target, read across chemical m-Tolylidene diisocyanate (26471-62-5) which is 70-80% structurally similar and Isophorone diisocyanate (4098-71-9),it can be considered that the 2,6-Toluene diisocyanate (91-08-7) is likely to be toxic to aquatic invertebrates at environmentally relevant concentrations and also can be classified in chronic category 3 as per the criteria of CLP regulation.

Toxicity to aquatic algae and cyanobacteria

Predicted data for the target chemical 2,6 -Toluene diisocyanate (CAS No. 91-08-7) and the study for its read across substance were reviewed to summarize the following information:

 

72 hrs aquatic toxicity study was predicted to assess toxic effects of the test compound 2,6-Toluene diisocyanate (CAS no. 91 -08 -7) and the result were predicted (SSS QSAR Prediction Model, 2016). The study was based on the effects of the test compound on Scenedesmus subspicatus in a static fresh watersystem. The predicted data suggests the effective concentration (EC50) for thetest compound 2,6-Toluene diisocyanate (CAS no. 91 -08 -7) was estimated to be 37.120 mg/l on the basis of growth rate. Thus, based on this value, it can be concluded that the test chemical 2,6-Toluene diisocyanate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

 

Short term toxicity to Desmodesmus subspicatus (algae) study was carried out for 72 hrs (OECD SIDS INITIAL ASSESSMENT PROFILE, SIAM 23, 2006). The test organism Desmodesmus subspicatus was obtained from Institute of Plant Physiology, University of Göttingen. The study was based on the effects of the read across compound Isophorone diisocyanate on algae in a static fresh water system at a temperature of23 ± 2°C. Nominal substance conc. used for the study was1.1; 2.2; 4.4; 8.8; 17.5; 35; 70 mg/l, respectively.300 ml Erlenmeyer flasks with stoppers with 100 ml of test medium; light chamber with shaker was used as a test vessel. The study was performed at a pH of 8.0-8.1 at 0 hrs with a light intensity of 120 uE/m2 x s. Cell count was determined with microcellcounter Sysmex F-300 Digitana at every 24 hours. Blank Inoculum control was setup during the study. Blank inoculum control contains inoculum in nutrient medium and dilution water. After 2 days of undisturbed growth, cell counts suddenly stayed constant (17.5 mg/l nominal) or even dropped markedly (> 17.5 mg/l nominal) leading to an inhibition of growth rate of 8.3 % at 17.5 mg/l and higher concentrations compared to 0% inhibition at all lower concentrations. In total, however, EC50 values are beyond the highest test concentration based on both biomass (area under the growth curve) and growth rate. Based on effect on growth rate of algae, the 72 hr EC50, NOEC and LOEC value was determined to be >70, 4.4 and 8.8 mg/l, respectively. Thus, based on EC50 value, it can be concluded that the substance Isophorone diisocyanate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

 

Short term toxicity to Scenedesmus subspicatus (algae)study was carried out for 72 hrs (OECD SIDS INITIAL ASSESSMENT PROFILE, 12th SIAM, 2001). The study was based on the effects of the read across compound 1,6-Hexamethylene diisocyanate on algae in a static fresh water system. Because of the rapid hydrolysis of test chemical, a water accommodated fraction (WAF) was prepared by direct weighing of 125 mg/l HDI into water. The test preparation was first stirred with an Ultra turrax for 60 sec/8000 rpm, then stirred for 24 hours with a magnetic stirrer and finally filtered. The resulting solution was analyzed to its TOC content and was used as a stock solution for further dilution steps. Based on effect on growth rate and biomass of Scenedesmus subspicatus, the 72 hr EC50 value was determined to be 77.4 mg/l and based on growth rate, the NOEC and LOEC value was determined to be 11.7 and 12.6 mg/l, respectively. Thus, based on EC50 value, it can be concluded that the substance1,6-Hexamethylene diisocyanate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

 

Based on the overall reported results for target and its read across substance, it can be concluded that the test substance 2,6-Toluene diisocyanate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

Toxicity to microorganisms:

Toxicity to microorganism was determined in2,6Toluene diisocyanate inPhotobacterium phosphoreum by MicrotoxTM test. The test was conducted for 5 ,15 and 30 minutes .The EC50 for 30 min was found to be 42 mg/L.