2-hydroxyethyl methacrylate

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)

Version / remarks:

1996

GLP compliance:

yes

Specific details on test material used for the study:

Source; Wako Pure Chemical Ind.,
Purity: 97.2%

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

The  medium dissolved  by the material, and the examination field liquid of 2,000 mg/L  is adjusted, in additon the filtration sterilisation was done with 0.45 um membrane filter. 

Test organisms (species):

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

Details on test organisms:

Strain Number: Selenastrum capricornutum ATCC22662

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23.2 - 23.7 °C 

pH:

7.9 -10.4

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

25.6, 64.0, 160, 400 and 1,000 mg/L - nominal
24.4, 61.3, 153, 401, and 1020 mg/L -TWM measured.
-Measured Concentrations (as mg/L): n. d. (<5.00) for control,  22.9-26.0 for the nominal concentration of 25.6, 57.1-65.7 for the nominal concentration of 64.0, 144-162 for the nominal concentration of 160, 391-410 for the nominal concentration of 400, and 994-1,020 for the nominal concentration of 1,000.

Details on test conditions:

Test Conditions: 
- Test Medium: OECD medium 
- Exposure Vessel Type: 100 ml-medium in a 500 ml-erlenmeyer flask  with a silicon cap which allow ventilation 
- Stock Solutions Preparations and Stability: The  medium dissolved  by the material, and the examination field liquid of 2,000 mg/L  is adjusted, in additon the filtration sterilization was done  with 0.45 um membrane filter. 
- Number of Replicates: Triplicate 
- Initial Cell Number: 10000 cells/mL 
- Water Temperature Range: 23.2 - 23.7 degree C 
- Light Condition: 4200 - 4500 lux, continuous

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

345 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

160 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

See Table 3 and Table 4.

Reported statistics and error estimates:

-Statistical Method: 
a) Data Analysis: Least squares method for EC, Dunnett test for NOEC 
b) Method of calculating mean measured concentrations: Time-weighted means

                                   

Table 4

Growth inhibition of Selenastrum capricornutum during 72 hrs exposure 2-Hydroxyethyl methacrylate

Nominal conc. (mg/l	No.	Area (*10.000) (0-72 hours)	Inhibition (%) (0-72 hours)
Control	1	1860	-
	2	1460	-
	3	1530	-
	Average	1620
25.6	1	1890	-17.0
	2	1500	7.31
	3	1860	-15.2
	Average	1750	-8.29
64.4	1	1830	-12.8
	2	1050	35.1
	3	1730	-6.88
	Average	1540	5.11
160	1	1670	-2.89
	2	1580	2.54
	3	1590	1.55
	Average	1610	0.398
400	1	756	53.3
	2	661	59.2
	3	707	56.3
	Average	708	56.3
1000	1	80.9	95.0
	2	94.0	94.2
	3	95.9	94.1
	Average	90.3	94.4

 

Table 4

Cell density of Selenastrum capricornutum during 72 hrs exposure 2-Hydroxyethyl methacrylate

Nominal conc. (mg/l	Cell density (+ 10000 cell/ml)
	No.	0 hrs	24 hrs	48 hrs	72 hrs
Control	1	1.0	4.8	29.4	91.4
	2	1.0	4.0	25.7	67.8
	3	1.0	5.0	23.9	74.9
	Average	1.0	4.6	26.3	78.0
	SD	0.0	0.5	2.8	12.2
25.6	1	1.0	3.8	29.9	95.4
	2	1.0	3.7	25.6	71.5
	3	1.0	3.9	28.8	94.9
	Average	1.0	3.8	28.1	87.3
	SD	0.0	0.1	2.2	13.7
64.4	1	1.0	3.4	26.9	96.5
	2	1.0	3.6	21.7	41.9
	3	1.0	3.2	27.2	88.5
	Average	1.0	3.4	25.2	75.6
	SD	0.0	0.2	3.1	29.5
160	1	1.0	3.4	27.9	81.1
	2	1.0	2.6	26.6	78.0
	3	1.0	2.9	24.3	83.4
	Average	1.0	3.0	26.2	80.9
	SD	0.0	0.4	1.8	2.7
400	1	1.0	2.1	15.0	33.8
	2	1.0	1.9	13.9	28.3
	3	1.0	1.8	12.5	35.2
	Average	1.0	2.0	13.8	31.4
	SD	0.0	0.1	1.3	3.6
1000	1	1.0	1.3	2.6	3.8
	2	1.0	1.2	3.4	3.6
	3	1.0	1.3	3.3	3.8
	Average	1.0	1.3	3.1	3.7
		0.0	0.1	0.4	0.1

 

Validity criteria fulfilled:

yes

Conclusions:

The 72 -hour EC50 and NOEC for Selenastrum capricornutum and based on growth rate was 345 mg/L and 160 mg/L, respectively.

Executive summary:

A 72 -hour growth inhibition study with 2-hydroxyethyl methacrylate to Selenastrum capricornutum was conducted under static conditions with 3 replicates inoculated at 10,000 cells/mL per test concentration exposed to nominal test concentrations of 0 (control), 25.6, 64.0, 160, 400, and 1000 mg/L. Water samples were measured for analytical verification of test concentrations 0 and 72 hours of exposure and the resulting time-weighted mean measured concentrations were non-detectable (control), 24.4, 61.3, 153, 401, and 1020 mg/L. The 72 -hour EC50 and NOEC based on growth rate was 345 mg/L and 160 mg/L, respectively.

Description of key information

A freshwater algal toxicity test with Selenastrum capricornutum exposed to 2-hydroxyethyl methacrylate and conducted under GLPs and following OECD TG 201 resulted in a 72-hour growth rate EC50 (ErC50) and NOEC of 345 and 160 mg/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

345 mg/L

EC10 or NOEC for freshwater algae:

160 mg/L

Additional information

One freshwater algal study with selenastrum capricornutum was available for 2-hydroxyethyl methacrylate and considered reliable for assessment of this endpoint. The study was conducted with selenastrum capricornutum and found to be of good quality and assigned a Klimisch score of one. The study was conducted for 72-hours, under static conditions, following OECD Test Guideline 201, and under GLPs. The study concluded that the 72-hour growth rate EC50 (ErC50) and NOEC was 345 and 160 mg/L, respectively and considered the key parameters for this endpoint.