Acetamide, N,N'-(ethenylmethylsilylene)bis[N-ethyl-

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 July - 19 November, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Study

Data source

Reference

Title:

Unnamed

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-[ethenyl(N-ethylacetamido)methylsilyl]-N-ethylacetamide

EC Number:

643-078-7

Cas Number:

87855-59-2

Molecular formula:

C11 H22 N2 O2 Si Si(CH3)(CH=CH2)[N(CH2CH3)(C(=O)CH3)]2

IUPAC Name:

N-[ethenyl(N-ethylacetamido)methylsilyl]-N-ethylacetamide

Test material form:

solid: compact

Details on test material:

Identification: Methylvinyl bis(n-ethylacetamido)silane (supplied as Dow
Coming® 1-6008)
Lot No.: 091217
CAS No.: 87855-59-2
Expiration Date: 26 December 20 I 0
Source: Korea Biogen Co. Ltd., 690 Sinduk-Ri, Sungnam-Myuan,
Chunan-City, Chungnam, 330-893, Korea
Physical Description: Amber Liquid (Stutls, 20 I 0)
Stability: Stable, refer to MSDS
Purity: 77.9 ± 0.3% area % purity (Stutts, :W I 0)
Solubility: Unknown, and/or may be soluble in other common organic solvents
Storage Conditions: Room Temperature

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the results, the 72-hour NOEC for growth rate was determined to be 100 mg/L. The 72-hour EC50 was empirically estimated to be > 100 mg/L.

Executive summary:

The purpose of this study was to determine the effects of the primary hydrolysis products of

methylvinyl bis(n-ethylacetamido)silane on the growth of the freshwater green alga,

Pseudokirchneriella subcapitata, formerly Selenastrum capricornutum, under static conditions.

Based on preliminary range-finding test results and consultation with the Study Sponsor, the

algae were exposed to methylvinyl bis(n-ethylacetamido )silane at nominal concentrations of 6.3,

13, 25, 50 and 100 mg a.i./L. Due to the rapid hydrolysis of the test substance (information

based on previous work and consultation with the study monitor), no attempt was made to

determine the toxicity of parent substance. The results of this study are based on nominal

concentrations.

Three replicate flasks were established for each treatment level and six for the control. At test

initiation, a 0.458-mL inoculum of Pseudokirchneriella subcapi/ata cells, at a density of

218 x 104 cells/mL, was aseptically introduced into each flask. This inoculum provided the

required cell density ofapproximately 1.0 x 104 cells/mL. The cell density in each test vessel

was monitored at 24, 48 and 72 hours after test initiation. Total yield and average specific

growth rate at 72 hours for each replicate vessel were calculated using the observed cell density

values. Temperature, pH and conductivity were measured during the test and were within

acceptable limits.

Cells exposed to all treatment levels tested were observed to be normal after 72 hours of

exposure. The 72-hour cell density in the control averaged 77.42 x 104 cells/mL. Cell density in

the 6.3,13,25,50 and lOO mg a.i.lL treatment levels averaged 83.25, 72.25, 73.58, 84.75 and

62.75 x:.l04 cells/mL, respectively.

The 0- to 72-hour yield in the control averaged 76.42 x 104 cellslmL. The 0- to 72-houryield in

the 6.3, 13,25, 50 and 100 mg a.i.lL treatment levels averaged 82.25, 71.25, 72.58, 83.75 and

61.75 x lif cellslmL, respectively. No significant reduction in 72-hour yield was detected in any

of the treatment levels tested compared to the control data, using WilIiams' Test. Based on these results, the 72-hour NOEC for yield was determined to be 100 mg a.i./L. The 72 hour EC50 was empirically estimated to be > 100 mg a.i./L.

The to 72 hour growth rate in the control averaged 1.50 days. The 0 to72 -hour growth rate

in the 6.3, 13, 25, 50 and 100 mg a.i./L treatment levels averaged 1.52, 1.48, 1.48, 1.53 and

1.43 days, respectively. No significant reduction in 0- to 72-hour growth rate was detected in

any of the treatment levels tested compared to the control data, using Williams' Test. Based on

these results, the 72-hour NOEC for growth rate was determined to be 100 mg a.UL. The

72-hour EC50 was empirically estimated to be > 100 mg a. i./L.

The following acceptance criteria were required by the protocol: the cell growth in the control

must increase from the initial density (1.0 x 104 cellslmL) by more than 16 times after 72 hours

of growth. During this study, the 72·hour cell density in the control was 77.42 x 104 cellslmL,

which exceeds the above criterion. Additionally, the mean coefficient of variation (CV) for

section-by-section specific growth rates (day 0 to I. I to 2 and 2 to 3) in the control replicates

should not exceed 35%. The CV for the average growth rate of the control for the entire test

period (0 to 72-hour growth rate) should not exceed 7%. For this study, the mean daily CV for

grnwth rates was 23% and the CV for 0 to 72 hours average growth rate was 4.0%, which meet

the above criteria.