4,4'-methylenedianiline

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Sampling took place at the start of the exposure period and after 72h, the end of the exposure period.

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Supplier: American Type Culture collection

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.4-23.2°C

pH:

pH 7.6 - 7.8 at the exposure initiation
pH 7.9 - 10.1 at the end of the exposure
(Control was pH 7.6 at initiation and pH 10.0 at end of exposure)

Nominal and measured concentrations:

Nominal concentrations: 0, 0.200, 0.430, 0.930, 2.00, 4.30, 9.30, 20.0 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

5.34 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: area under growth curve

Remarks on result:

other: 0-72h duration

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

13.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 24-48h duration

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

14.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 24-72h duration

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.93 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: area under growth curve

Remarks on result:

other: 0-72h duration

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

9.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 24-48h duration

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

9.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 24-72h duration

Results with reference substance (positive control):

Sensitivity: The 72h EC50 (area under growth curve) with potassium dichromate was 0.467mg/l. This value was consistent with EC50 values obtained at the laboratories since 1996 (n=9) (mean value = 0.437 +/- 0.0826 mg/l, range = 0.285 - 0.543 mg/l)

Reported statistics and error estimates:

EC50 values were deteremined by least square linear regression analysis of the logarithm of test concentration against percent growth inhibition relative to the control.

Validity criteria fulfilled:

yes

Description of key information

The EC50 (= 14.4 mg/L) and NOEC (= 9.3 mg/L) values based on the growth rate indicate that MDA is acutely harmful to algae.

Key value for chemical safety assessment

EC50 for freshwater algae:

14.4 mg/L

EC10 or NOEC for freshwater algae:

9.3 mg/L

Additional information

An experimental study according to OECD guideline 201 and GLP regulations with the freshwater algae Pseudokirchnella subcapitata revealed an EC50 of 14.4 mg/L and a NOEC of 9.3 mg/L (Mitsubishi, 2002). The results were based on the growth rate and indicate that the test item is acutely harmful to algae.

An additional study with the freshwater algae Desmodesmus suspicatus achieves slightly less sensitive values with an EC50(72 h) of 21 mg/L (Rufli & Mueller, 1985). No chronic (EC10 or NOEC) values were documented, and study was not performed according to GLP regulations. Therefore, this study was rated less reliable. Nevertheless, these values are within the same range as the results from the Mitsubishi key study and support these results.