2-methyl-m-phenylene diisocyanate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

The supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Prediction is done using QSAR Toolbox version 3.4.

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.4.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2,6-Toluene diisocyanate
- Molecular formula: C9 H6 N2 O2
- Molecular weight: 174.1584 g/mol
- Smiles notation: c1(cccc(c1C)N=C=O)N=C=O
- InChl: 1S/C9H6N2O2/c1-7-8(10-5-12)3-2-4-9(7)11-6-13/h2-4H,1H3
- Substance type: Organic
- Physical state: Liquid

Analytical monitoring:

not specified

Details on sampling:

not specified

Vehicle:

not specified

Details on test solutions:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

not specified

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Remarks on exposure duration:

not specified

Post exposure observation period:

not specified

Hardness:

not specified

Test temperature:

20 +/- 1 degree C

pH:

7.8-8.0

Dissolved oxygen:

8.4-8.6 mg/l

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

not specified

Details on test conditions:

not specified

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

33.383 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

not specified

Results with reference substance (positive control):

not specified

Reported statistics and error estimates:

not specified

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((("a" or "b" or "c") and "d") and("e" and(not "f")) ) and("g" and "h") )

Domain logical expression index: "a"

Referential boundary:The target chemical should be classified as Acylation AND Acylation >> Isocyanates and Isothiocyanates AND Acylation >> Isocyanates and Isothiocyanates >> Isocyanates by DNA binding by OECD

Domain logical expression index: "b"

Referential boundary:The target chemical should be classified as Acylation AND Acylation >> (Tio)carbamoylation of protein nucleophiles AND Acylation >> (Tio)carbamoylation of protein nucleophiles >> Isothiocyanates, Isocyanates AND AN2 AND AN2 >> Direct carbamoylation of protein amines AND AN2 >> Direct carbamoylation of protein amines >> Isocyanates and Diisocyanates by Protein binding by OASIS v1.4

Domain logical expression index: "c"

Referential boundary:The target chemical should be classified as Acylation AND Acylation >> Isocyanates and Related Chemicals AND Acylation >> Isocyanates and Related Chemicals >> Isocyanates by Protein binding by OECD

Domain logical expression index: "d"

Referential boundary:The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "e"

Referential boundary:The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "f"

Referential boundary:The target chemical should be classified as Halogens OR Metalloids by Groups of elements

Domain logical expression index: "g"

Parametric boundary:The target chemical should have a value of log Kow which is >= 1.17

Domain logical expression index: "h"

Parametric boundary:The target chemical should have a value of log Kow which is <= 4.75

Validity criteria fulfilled:

not specified

Conclusions:

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)was estimated to be 33.382987976 mg/L on the basis of intoxication at 20 degree C.

Executive summary:

48 hrs aquatic toxicity studies (SSS QSAR prediction model, 2016) were conducted to assess toxic effects of2, 6-Toluene diisocyanate (91-08-7) andthe 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.

Description of key 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.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

33.383 mg/L

Additional information

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.