Methacrylamide

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Japanese government peer-reviewed the documents, audited selected studies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Supplier: KISHIDA CHEMICALS CO., Ltd (Lot No. D12358J)
Purity: >= 98 %

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

Test Organism:
-strain: ATCC-22662
-supplier: American Type Culture Collection
-acclimation: 3 days
-initial cell concentration: 1X10E+4 cells/mL

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

original test: 21.8 - 22.8 (mean 22.5) °C
supplemental test: 21.2 - 23.0 (mean 22.5) °C

pH:

original test: 7.0 - 7.3 at start, 8.1-8.6 at end of test
supplemental test: 7.3 - 7.5 at start, 8.9 - 9.0 at end of test

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

0, 1000 mg/L (original test, nominal) actual concentration measured and greater than 80% of the nominal concentration
0, 556 mg/L (supplemental test, nominal) actual concentration measured and greater than 80% of the nominal concentration

Details on test conditions:

TEST MEDIUM CHEMISTRY: OECD medium
TEST SYSTEM (closed system)
-exposure vessel type: 100 mL medium in a 300 mL Erlenmeyer flask with a porous plug
-number of replicates: 3
-test temperature: 21 - 25 degree C
-pH: no adjustment during exposure period
-intensity of irradiation: 4,000 - 5,000 lux
-photoperiod: continuous
-shaking: 100 rpm
TEST PARAMETER: cell concentration (cells/mL)

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: actual concentration measured and greater than 80% of the nominal concentration

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: actual concentration measured and greater than 80% of the nominal concentration

Details on results:

Results:
Table 1 NOMINAL/MEASURED CONCENTRATION
-----------------------------------------------------------
Nominal Measured conc. (mg/L) conc.
(% of nominal) (mg/L) 0 hr* 72 hr**
-----------------------------------------------------------
Control <0.5 <0.5
1000 mg/L 1011 (101.1) 926 (92.6)

Control <0.5 <0.5
556 mg/L 599 (107.7) 556 (100.0)
-----------------------------------------------------------
*: initial **: final


EFFECT DATA/ELEMENT VALUES:
-area method: EbC50 (0 - 72hr ) > 1000 mg/L
NOEbC (0 - 72hr ) = 556 mg/L
-rate method: ErC50 ( 24 - 48hr ) > 1000 mg/L
NOErC ( 24 - 48hr ) = 1000 mg/L
ErC50 ( 24 - 72hr ) > 1000 mg/L
NOErC ( 24 - 72hr ) = 1000 mg/L

Table 2 AVERAGE CELL DENSITY OF Selenastrum capricornutum
-----------------------------------------------------------
Nominal conc. Cell Density (1x10E+4 cell/mL)
(mg/L) 0 hr 24 hr 48 hr 72 hr
-----------------------------------------------------------

Control 1.0 5.5 34.7 201.6
1000mg/L 1.0 5.0 30.6 197.3

Control 1.0 5.2 33.5 204.4
556mg/L 1.0 5.3 40.6 212.2
-----------------------------------------------------------
Table 3 AVERAGE GROWTH INHIBITION
-----------------------------------------------------------
Nominal Inhibition
conc. area method growth rate growth rate
(mg/L) (0-72hr)% (24-48hr)% (24-72hr)%
-----------------------------------------------------------

Control - - -
1000 mg/L 4.82 1.59 -2.08

Control - - -
556 mg/L -7.99 -9.36 -0.34
-----------------------------------------------------------

Results with reference substance (positive control):

REFERENCE SUBSTANCE: K2Cr2O7 EbC50 (72hrs) = 0.52 mg/L

Reported statistics and error estimates:

STATISTICS: F&T-test; Yukms StatLight #3 "Pairwise Comparisons" EA Japan

Validity criteria fulfilled:

yes

Conclusions:

At a limit concentration of 1000 mg/l (nomial), methacrylamide showed no growth inhibition in an Algae, Growth Inhibition Test OECD 201.
ErC50 (72h) > 1000 mg/l (measured/nominal), NOErC = 1000 mg/l (measured/nominal)

Executive summary:

In a 72-hour acute toxicity study, the cultures of Pseudokirchneriella subcapitata, strain ATCC-22662 were exposed to control and test item at nominal/measured concentrations of 1000 mg a.i./L in accordance with the Algae, Growth Inhibition Test, OECD 201  The NOEC and ErC₅₀values based on growth inhibition were 1000 mg/l and > 1000 mg a.i./L, respectively.  The % growth inhibition in the treated algal culture as compared to the control ranged from -2.08 to 1.59 

There were no compound related phytotoxic effects.

This toxicity study is classified as acceptable and satisfies the guideline requirements for Algae, Growth Inhibition study.

Results Synopsis:

Test organism: Pseudokirchneriella subcapitata

Test type: static

72 -hr EC50: > 1000 mg/l

72 -hr NOEC: 1000 mg/l

Description of key information

In a 72-hour acute toxicity study, the cultures of Pseudokirchneriella subcapitata, strain ATCC-22662 were exposed to control and test item at nominal/measured concentrations of 1000 mg a.i./L in accordance with the Algae, Growth Inhibition Test, OECD 201  The NOEC and ErC₅₀values based on growth inhibition were 1000 mg/l and > 1000 mg a.i./L, respectively.  The % growth inhibition in the treated algal culture as compared to the control ranged from -2.08 to 1.59 

There were no compound related phytotoxic effects.

This toxicity study is classified as acceptable and satisfies the guideline requirements for Algae, Growth Inhibition study.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 000 mg/L

EC10 or NOEC for freshwater algae:

1 000 mg/L