m-tolyl isocyanate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Concept NEN reports 6501 from the Dutch Standard Organization (1980)

Principles of method if other than guideline:

additionaly: Canton et al. (1975)
NEN 6501 (1980), Determination of acute toxicity with Daphnia magna. Dutch Standardization Organization, Rijswijk, The Netherlands

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

-Only the lowest and highest tested concentrations were measured by GC

Vehicle:

not specified

Details on test solutions:

- were prepared in "Dutch Standard water", (DSW, Canton and Sloff, 1982)

Test organisms (species):

Daphnia magna

Details on test organisms:

-Age at study initiation: <1d

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

ca. 1 mmol/L

Test temperature:

18-20°C

Nominal and measured concentrations:

ratio of concentrations: 3.2

Details on test conditions:

-test volume per vessel: 1 L
-number of replicates per concentration: 2
-25 daphnids per vessel

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.73 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: corrected for measured recoveries

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Based on analytical measurements, the substance was shown to be stable over the test duration. Therefore, nominal concentrations can be used.

Validity criteria fulfilled:

not specified

Remarks:

Since the test is poorly reported the validity criteria cannot be assessed sufficiently. Nevertheless the test is considered as valid based on the data given

Conclusions:

For the substance a 48h-LC50 of 0.75 mg/L was determined on Daphnia magna.

Executive summary:

The short-term toxicity of m-toluidine towards invertebrates was tested using Daphnia magna yielding a 48h-LC50 of 0.75 mg/L related to nominal concentrations. The used guideline was according to the Concept NEN reports 6501 from the Dutch Standard Organization (1980) (Hermens, 1984).

Description of key information

48 h LC₅₀ = 0.75 mg/L (Hermens, 1984)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.75 mg/L

Additional information

Due to rapid hydrolysis of isocynantes, the acute toxicity of the primary amine transformation product of m-tolyl isocyanate, m-toluidine, is presented as the most relevant endpoint for use in the CSA.

The short-term toxicity of m-toluidine towards invertebrates was tested using Daphnia magna yielding a 48h-LC50 of 0.75 mg/L related to nominal concentrations. The used guideline was according to the Concept NEN reports 6501 from the Dutch Standard Organization (1980) (Hermens, 1984).