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 Acute Toxicity to Aquatic Plants

CAS Number : 3194-55-6

Sponsored 

Chemical 

Name : 

Cyclododecane, 1,2,5,6,9,10-hexabromoTest Substance - Acute Toxicity To Aquatic Plants

Test 

Substance: (25637-99-4) Cyclododecane, hexabromoTest Substance 

Purity/

Composition 

and Other Test 

Substance 

Comments: 

 Estimated by Calculation 

Test Substance 

Result Type: Estimated 

Method - Acute Toxicity To Aquatic Plants

Year Study 

Performed: 2004 

Method/

Guideline 

Followed: 

 OECD 201 

Other Method/

Guideline: 

Deviations 

from Method/

Guideline: 

 

Species: Skeletonema costatum 

GLP: Yes 

Analytical 

Monitoring: Yes 

Test Type: 

Test Vessel: 

Water Media 

Type: 

Test 

Concentrations: 

Nominal and 

Measured 

Concentrations: 

 

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Exposure 

Period: 72 Hours 

Vehicle Used: 

Vehicle Name: 

Vehicle Amount 

and Units: 

Alkalinity: 

Dissolved 

Oxygen: 

pH Value: 

Test 

Temperature 

and Units: 

 

Photo (Light/

Dark): 

Salinity: 

TOC: 

Water 

Hardness: 

Method/

Guideline 

Test Conditions 

Remarks: 

 HBCD: A 72-Hour toxicity test with the marine diatom (Skeletonema costatum) 

The objective of this study was to determine the toxicity of water-soluble components of 

hexabromocyclododecane (HBCD) to the marine diatom Skeletonema costatum, using a saltwater algal media 

passed through a generator column saturated with HBCD. 

This study was performed according to Good Laboratory Practices, IS0 10253:1995, OECD 201, and EU 

Directive 92/69/EEC, Method C.3. The test article was a composite of the commercial products of Albemarle 

Corporation, Dead Sea Bromine Group and Great Lakes Chemical Corporation. Composite = 7.67% alpha, 

5.15% beta and 83.04% gamma. 

The experimental design was developed based on prelminary work. The marine diatom was exposed to a single 

test concentration (produced via water generator column) of HBCD in salwater algal media, a negative control 

(also referred to as Control with Column) and a media control (also referred to as Control no Column) for 72 

hours. The single test concentration was prepared using algal media passed through a comlumn generator 

packed with a solid support coate with HBCD to achieve the test concentraiton of HBCD in saltwater algal 

medium. Measured test concentrations were determined from samples of test medium collected from teh 

treament and each control group at the beginning of the test and at test termination. 

At test initiation an inoculum of the algal cells was added to each test chamber to achieve a nominal 

concentratin of approximately 77,000 Skeletonema cells/ml. Samples were collected from each replicate test 

chmaber at approximately 24-hour intervals during the test to determine cell densities, which were subsequently 

used to caluculate areas under the growth curve (biomass) and growth rates. Cell densitites, biomass and 

growth rates were used to calculate percent inhibitoin vlaues relative to the control over the 72-hour exposure 

period. No-oberved-effect-concentrations (NOEC) were determ ined at 72 hours through statistical evaluation of 

the cell densities, biomass and growth rates, as well as examination of the concentration-response pattern. 

The analytical method for the 3 HBCD stereoisomers in saltwater algal medium was based on methodology 

developed by Wildlife International LTD. It used an HPLC interfaced with a triple quadrupole LC mass 

spectromer operated in single-quadrupole selective ion monitoring mode. The LOQ was 0.5 ug a.i./L. The Day 0 

and 3 arithmetic mean measured test concentrations for Gamma, Beta, Alpha and total HBCD was 1.61, 8.86, 

30.5 and 41.0 ug a.i./L, respectively. Arithmetic mean measured test concentrations were used to calculate the 

NOEC values. 

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Limit Test: 

Test Results - Acute Toxicity To Aquatic Plants

NOEC Exposure 

Duration: 

NOEC: < 41 

LOEC Exposure 

Duration: 

LOEC: 

NOELR 

Exposure 

Duration: 

 

NOELR: 

LOELR 

Exposure 

Duration: 

 

LOELR: 

Effect: Exposure 

Duration

Exposure 

Units

Type % Value 

Description

Mean 

Value 

or 

Lower 

Mean 

Value

Upper 

Mean 

Value

Units Basis 

for 

Effect

Basis for 

Concentration

EC 50 

 % > 41 ug/L

Results 

Remarks: 

 S. costatum were exposed to a single concentraion of 41 .O ug a.i./L of toal HBCD and evaluated for effects on 

cell density, area under the growth curve (biomass) and growth rate. After 72 of exposure, inhibition of cell 

density, biomass and growth rate in the treated group was 19, 21 and 7.3%, respectively, relative to control no 

column. Similarly, relative to the control with column, inhibition of cell density, biomass and growth rate was 31, 

31 and 11%, respectively. The treated group was statistically different from both control groups (p<0.05) 

Since there were effects observed, the 72 hour NOEC and EC50, based on cell density, biomass and growth rate 

were < 41.0 ug a.i./L and > 41.0 ug a.i./L total HBCD, respectively. The total HBCD concentration was 

composed of 1.61 ug a.i./L gamma; 8.86 ug a.i./L beta and 30.5 ug a.i./L alpha isomers. 

Reliability/Data Quality - Acute Toxicity To Aquatic Plants

Reliability: Valid Without Restrictions 

Reliability 

Remarks: Risk Assessment, Critical study for SIDS endpoint 

Key Study 

Sponsor 

Indicator: 

 

Reference - Acute Toxicity To Aquatic Plants

Reference: Desjardins D, MacGregor J, Krueger H. 2004. Hexabromocyclododecane (HBCD): a 72-hour toxicity test with 

the marine diatom (Skeletonema costatum). Final Report. Wildlife International LTD Project Number: 439A-125. 

Wildlife International LTD, Easton, MD. 

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