Reaction mass of Disodium decyl(sulphonatophenoxy)benzenesulphonate and Disodium oxybis[decylbenzenesulphonate]

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, guideline study

Justification for type of information:

Please see read across justification document.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: Holst, R. W. (1986). Standard Evaluation Procedure - Non-Target Plants: Growth and Reproduction of Aquatic Plants - Tiers 1 & 2 EPA 540/9-86-134, Washington, D.C.

Deviations:

no

Remarks:

Not specified in report

Qualifier:

according to guideline

Guideline:

other: Miller, W.E., Greene, J.C. and Shiroyama, T. (1978). The Selenastrum capricornutum Printz. Algal Assay Bottle Test. EPA-600 / 9-78-018, Corvallis, OR.

Deviations:

no

Remarks:

Not specified in report

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
None

Analytical monitoring:

yes

Details on sampling:

Days on which analyses of XDS-8174.00 in algal medium were performed were day 0, day 3, and day 5.

Vehicle:

no

Details on test solutions:

Various concentrations of XDS-8174.00 were prepared in algal medium.

Test organisms (species):

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

Details on test organisms:

Selenastrum capricornutum was the organism used to test the phytotoxicity of XDS-8174.00. Axenic samples of this organism were procured from the Starr Algal collection at the University of Texas, Austin, TX, USA. This sample of S. capricornutum was received June 10, 1982. Stock cultures of this organism have been maintained axenically by weekly transfer into fresh sterile medium.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

5 d

Post exposure observation period:

None

Hardness:

No data

Test temperature:

25.0-25.4C

pH:

7.2-7.9

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

Nominal- 0, 64.8, 108, 300, 600, and 1000 mg/L
Actual- 0, ND (0.1 mg/L), 64.93, 108.25, 179.00, 297.50, 618.80, and 1010.2 mg/L

Details on test conditions:

Test Methodology
The algal test lasted for five days. The endpoints of choice were the total number of cells per milliliter and the total cell volume x E4 um3 per
milliliter in contrast to that of the controls. The test methodology was that recommended by U.S. EPA.

Test Conditions
The test medium was that designed by Bold [2] with the omission of ethylenediaminetartaric acid.

Temperature, C
range 25.0 - 25.4
mean 25.2 +/- 0.3

Light
Intensity, lux
range 3210 - 5350
mean 4517 +/- 534
Photo-p eriod, hours- continuous
pH
1010.2 mg/L
without growth 7.4 +/- 0.6
with growth 7.6

618.8 mg/L
without growth 7.5 +/- 0.7
with growth 7.6

297.5 mg/L
without growth 7.4 +/- 0.2
with growth 7.2

179.0 mg/L
without growth 7.4 +/- 0.1
with growth 7.2

108.25
without growth 7.5 +/- 0.1
with growth 7.2

64.93
without growth 7.6 +/- 0.1
with growth 7.4

Control
without growth 7.9 +/- 0.4
with growth 7.6 +/- 0

Observations Daily: Temperature, light intensity,Total number of cells/mL, and Cell Volume x E4um3/ mL

Initiation of test: pH-high, middle, low concentrations and control
Termination of test: pH-high, middle, low concentrations and control

Habitat- Environmental growth chamber
Agitation- 100/minute
Flask- glass Erlenmeyer
capacity, mL- 250
content, mL- 100
Effect of criteria- Net decrease of total cell/mL or total cell volume x E4um3/mL over that of controls

Experimental
The definitive test consisted of a series of six concentrations each replicated three times and a control replicated six times. Each concentration was at least 60% of the next higher concentration. Each vessel contained an initial cell density of 20,000 cells/mL. The initial and final pH of the control, low, middle and high concentrations were measured and recorded. In addition, pH measurements were taken at the termination of the test in a variety of
concentrations in the presence of the algae to determine whether the latter had had any effect on the initial hydrogen ion concentration. A counting blank containing the growth medium, no algae, but test material was included with each concentration series. Flasks containing algae (N=24) were
monitored daily for growth. The definitive test was carried out for five days.

Reference substance (positive control):

no

Duration:

5 d

Dose descriptor:

NOEC

Effect conc.:

297.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: cell number and volume

Duration:

5 d

Dose descriptor:

EC50

Effect conc.:

872.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 95% C.I.: 644-1101 mg/L

Duration:

5 d

Dose descriptor:

EC50

Effect conc.:

1 016 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: mean total cell volume x E4 um3/mL

Remarks on result:

other: 95% C.I.: 103-1928 mg/L

Duration:

4 d

Dose descriptor:

NOEC

Effect conc.:

297.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: cell number and volume

Duration:

4 d

Dose descriptor:

EC50

Effect conc.:

840.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 95% C.I.: -37- 1717 mg/L

Duration:

4 d

Dose descriptor:

EC50

Effect conc.:

949 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: mean total cell volume x E4 um3 / mL

Remarks on result:

other: 95% C.I.: 198-1701 mg/L

Details on results:

A 50% reduction in mean total cell count per milliliter found in the controls for day 5 would be 2516383.33, for day 4 would be 1216763.89 and for day 3 would be 223842.22. A regression line calculated for the mean total cell count in relation to concentration of toxicant is as follows:

day 5 Y= 5192727.8-3067.3X
day 4 Y= 2226013.9-1201.4X
day3 Y= 382528.7-36.9X
where X = concentration

To obtain these 50% reductions in mean total cell counts per milliliter found in the controls, the following concentrations of XDS-8174.00 would be
required:
day 5 872.5(644-1101) mg/L
day 4 840.1 (-37,1717) mg/L
day 3 4303 (-10494,19100) mg/L

The no observable effect levels using Dunnett's t test were 297.5 mg/L for both day 5 and day 4 and could not be calculated for day 3.

A 50% reduction in mean total cell volume x E4 um3/mL found in the controls for day 5 would be 6078 for day 4 would be 3428 and for day 3 would
be 862. A regression line calculated for the mean total cell volume x E4um3/mL in relation to concentration of toxicant is as follows:

day 5 1016 (103-1928) mg/L
day 4 949 (198-1701) mg/L
day 3 15939 (-116898, 148775 mg/L

The no observable effect levels using Dunnett's t test were 297.5 mg/L for both day 5 and day 4 and could not be calculated for day 3.
According to the U.S. EPA classifactory scheme XDS-8174.00 is not toxic to S. capricornutum.

The results of the chemical analyses show that the analyzed concentrations agree well with the nominal concentrations. In addition, comparison of the Day 0, 3 and 5 results show no apparent degradation of XDS-8174.00 in algal medium over the course of the study.

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

None

None

Validity criteria fulfilled:

not specified

Conclusions:

The no observable effect levels using Dunnett's t test were 297.5 mg/L for both day 5 and day 4 and could not be calculated for day 3. According to the U.S. EPA classifactory scheme XDS-8174.00 is not toxic to S. capricornutum.

Executive summary:

The purpose of this study was to estimate the level of phytotoxicity (50% reduction in the number of cells per milliliter in contrast to the controls and 50% reduction in total cell volume x E4 um3 per milliliter in contrast to the controls) of XDS-8174.00 to the green alga Selenastrum capricornutum.

The EC50 values are presented below and are based on measured test concentrations:

Cell Count / mL Cell Volume x E4 um3 / mL

Day 5 872(644-1101) mg/L 1016(103-1928) mg/L

Day 4 840(-37,1717) mg/L 949(197-1701) mg /L

The no observable effect level as calculated using Dunnett's t test was 297.5 mg/L in all cases for both days. Using the categorization scheme of U.S. EPA,

XDS-8174.00 is classified as not toxic to Selenastrum cavricornutum.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, guideline study

Justification for type of information:

Please see read across justification document.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Remarks:

Not specified in report

Qualifier:

according to guideline

Guideline:

other: Directive 92/69/EEC; Method C-3.

Deviations:

no

Remarks:

Not specified in report

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No data

Analytical monitoring:

yes

Details on sampling:

During the final test, samples were taken from three concentrations, i.e. 10, 32 and 100 mg/l and the blank-control.
Sampling: Frequency at t = 0 h and t = 72 h
Volume: 10 ml
Storage: Samples were transferred to Analytical Chemistry directly after sampling.

Compliance with the Quality criteria regarding maintenance of actual concentrations was demonstrated by running a test vessel at the highest
substance concentration but without algae and samples for analysis were taken at the start and the end of the test period.

Additionally, reserve samples of 10 ml were taken from all test solutions and stored in a deep-freeze until possible analysis for a maximum of three
months or until delivery of the final report.

Vehicle:

no

Details on test solutions:

The test solutions were prepared using a stock solution in ISO-medium. For this purpose a weighed amount of test substance was added quantitatively to ISO-medium providing a nominal concentration of 100 mg/l. Volumes of 50 ml from each test solution were added to the respective vessels. Subsequently, a volume of 0.23 ml of the algal suspension was added to provide for an algal density of 1.10E4 cells/ ml . At the start of the test all test solutions were clear and colorless.

Test organisms (species):

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

Details on test organisms:

Speci es Selenastrum Capricornutum, strain : CCAP 278/4.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

22-23C

pH:

8.3

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

Nominal- 10, 18, 32, 56 and 100 mg/l, controls- test medium without test substance or other additives (blank)

Details on test conditions:

Test type- Static
Test vessels- 100 ml , all-glass
Milli-Q water- Tap water purified by reverse osmosis and then passed over activated carbon and ion-exchange cartridges ( Millipore Corp., Bedford, Mass., USA).

Medium- ISO-medium according to the ISO-Standard "Algal growth inhibition test " Nov. 1989; formulated using Milli-Q water preventing precipitation and with the following composition:
NH4Cl 15 mg/l
MgCl2.6H20 12 mg/l
CaCl2.2H20 18 mg/l
MgS04.7H20 15 mg/l
KH2P04 1.6 mg/l
FeCl3.6H20 80 ug /l
Na2EDTA. 2H20 100 ug/l
H3B03 185 ug/l
MnC12.4H20 415 ug/l
ZnCl2 3 ug/l
CoCl2.6H20 1.5 ug/l
CuCl2.2H20 0.01 ug/l
Na2MoO4.2H20 7 ug/l
NaHC03 50 mg/l
Hardness (Ca+Mg) 0.24 mmol/l (24 mg CaCO3/l)

Cell density- An initial cell density of 1 E4 cells/ ml .
Test duration- 72 hours
Illumination- Continuously using TLD-lamps of 18 Watt ( Philips, Spain) yielding 7000 - 8000 lux .
Incubation- During incubation the algal cells were kept in suspension by continuous shaking.
Test concentrations- 10, 18, 32, 56 and 100 mg/l
Controls- Test medium without test substance or other additives (blank)
Replicas-
3 replicas of each test concentration.
6 replicas of the blank-control.
1 replica of the highest concentration without algae.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

other: EC50 for cell growth inhibition (EBC50:0-72h)

Effect conc.:

42 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI 30-68 mg/L

Duration:

72 h

Dose descriptor:

other: EC50 for growth rate reduction (ErC50:0-72h)

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: Beyond the range tested

Duration:

72 h

Dose descriptor:

other: NOEC for groth rate reduction

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

other: NOEC for inhibition of biomass formation

Effect conc.:

< 10 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Details on results:

Range-finding test:
The extinction values indicated no inhibition of cell growth at concentrations up to and including 10 mg/l with significant inhibition at 100 mg/l.

Final test:
Measured test substance concentrations
At the start of the test, the actual test concentrations were in agreement with nominal. At the end of the 72-hour period the measured concentrations
had remained constant for all three test concentrations sampled.

Mean cell densities
Inhibition of cell growth increased with increasing concentration of DOWFAX 8390-D from 10 mg/l upwards resulting in 62 % inhibition at 100 mg/l. Note the rather high variation in growth inhibition between the three replicas at 10 mg/l (42, 24 and 12 % for vessels 1, 2 and 3, resp.).
Statistically significant inhibition of cell growth was found at test concentrations of 10 mg/l and higher (Williams' test : P=0.05).

Growth rate reduction increased slowly with increasing concentration of DOWFAX 8390-D from 10 mg/l upwards resulting in 23 % reduction at 100 mg/l. Statistically significant reduction of growth rate was found at test concentrations of 10 mg/l and higher (Williams' test: P=0.05).

Acceptability of the test
In the controls, cell density increased by an average factor of 107 within 3 days. Analysis of samples taken from all test solutions including the one
without algae showed that the actual exposure concentration of the test substance remained above 80 % relative to the initial concentration. Further, all test conditions remained within the ranges prescribed by the protocol.

Results with reference substance (positive control):

Resul t s :
The 72-hour EC50 for growth inhibition (EBC50:0-72h) was 0.69 mg/l.
The 72-hour EC50 for growth rate reduction (ERC50:0-72h) was 1.32 mg/l.

These results were in agreement with what was expected on the basis of historical data:
The historical ranges of the 72h EC50 for growth inhibition and the 72h EC50 for growth rate reduction lie between 0.32 and 1.8 mg/l, with < 50 %
response at 0.32 mg/l and > 50 % rsose at 1.8 mg/l.

Reported statistics and error estimates:

No data

None

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study with Selenastrum capricornutum, DOWFAX 8390-D inhibited cell growth of this fresh water algae species
significantly at 10 mg/l and higher. Although statistically significant, DOWFAX 8390-D only slightly reduced growth rate at 10 mg/l (< 10 %).

The EC50 for cell growth inhibition (EbC50: 0-72h) was 42 mg/l with a 95 % confidence interval ranging from 30 to 68 mg/l. The EC10 for cell growth inhibition (EbC10: 0-72h) was estimated to be 3 mg/l.

The EC50 for growth rate reduction (ErC50: 0-72h) was beyond the range tested. The EC10 for growth rate reduction (ErC10:0-72h) was estimated to lie between 10 and 18 mg/l. Considering a response of < 10 % as not biologically significant the NOEC for growth rate reduction was 10 mg/l.

Executive summary:

DOWFAX 8390-D surfactant is the dry form of a diphenyloxide based anionic surfactant which consists of disodium di- and monohexadecyldiphenyloxide disulfonate. The acute toxicity of the material was evaluated in alga strain Selenastrum capricornutum. The study conformed to OECD Guideline for Testing of Chemicals Number 201 and to Directive 92169lEEC; Method C-3.

Subsequent to a range-finding study the cells of S. capricornutum were exposed to triplicate samples of an aqueous nutrient solution (aprox. 50 ml) containing 10, 18, 32, 56 and 100 mg/l of the test material over a period of 72 hours. Additional 6 parallel samples were included as blank controls without addition of the test substance. Furthermore, one sample with the highest test substance concentration without algae was incubated. The incubation took place on a laboratory shaker under continuous illumination (7000-8000 lux). Samples of the algae suspensions were taken at 24, 48 and 72 hours and the cell number was determined by turbidity measurements with the use of a spectrophotometer at 720 nm. The area under the growth curve and the growth rates were used as a base for the calculation of the concentration leading to 50 % growth inhibition: EbC50 and ErC50 referring to the area under the growrth curve (biomass) and to the growth rate, respectively.

The nominal effective 72-hour EbC50 of DOWFAX 8390-D surfactant tested with S. capricornutum was 42 mg/l (95 % confidence interval 30 - 68 mg/l). The EC50 value for growth rate reduction (ErC50: 0-72h) was beyond the test concentrations assayed. The No Observed Effect Concentration (NOEC) for growth rate reduction and inhibition of biomass formation was 10.0 and < 10.0 mg/l, respectively.

Additional information

No toxicity data are available from testing of Dowfax 3B2 with aquatic algae. Read across was used from Dowfax 2A1 and Dowfax 8390 (members in the ADPODS category) which are not acutely toxic to freshwater algae. For Dowfax 2A1, the 96h EyC50 was 840 mg/l based on cell number, with a NOEC of 298 mg/L. The 72 hr ErC50 of Dowfax 8390 to algae based on growth rate was >100 mg/l (a.i), with a NOEC of 10 mg/l.