Sodium 2-biphenylate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study according to national standards

Qualifier:

according to guideline

Guideline:

other: Procedures recommended by the ASTM Subcommittee on Safety to Aquatic toxicology: ASTM Standard E729-80, Standard Practice for Conducting Acute Toxicity Tests with Fish, Macroinvertebrates, and Amphibians, Philadelphia, PA, 1980.

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.5, 1.0., 10 mg a.i./L
- Sampling time: 0, 48 h

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test concentrations were prepared by adding appropriate amounts of 0.2 mg/mL aqueous stock solution of the test material in daphnid dilution water to test vessels containing approximately 100 mL of dilution water and bringing the final volume up to 200 mL with additional dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Strain: Daphnia magna STRAUS
- Source: Laboratory culture
- Age at study initiation: Juvenile Daphnia magna 1st instar
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

148 mg/L as CaCO3

Test temperature:

19.7 - 21.0 °C

pH:

7.9 - 8.1

Dissolved oxygen:

O2 saturation: > 95%

Nominal and measured concentrations:

Nominal test concentrations: control, 0.78, 1.3, 2.2, 3.6, 6.0, 10.0 mg/L
Recovery rates: 92 - 100% of nominal

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, nominal volume, fill volume: Pyrex beakers, 250 ml, 200 ml
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: standard dilution water; pumped from the upper Saginaw Bay of Lake Huron of Whitestone Point. The water is carbon filtered, UV irradiated and pH adjusted with CO2 in the laboratory prior to use. In addition to the above, the most recent analysis of selected organics, pesticides and PCBs or both dilution waters indicated acceptably low levels.
- Alkalinity: 45 mg/L
- Ca/Mg ratio: 38250 µg/L / 7670 µg/L
- Conductivity: 330 µS/cm
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: 16 h/8 h light dark cycle

EFFECT PARAMETERS MEASURED: Immobility after 24 and 48 hours

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.78 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

- Mortality of control: < 10% after 48 h

Executive summary:

The study from Dill (1985) was conducted according to ASTM Standard E729-80, Standard Practice for Conducting Acute Toxicity Tests with Fish, Macroinvertebrates, and Amphibians and revealed a LC50 of 2.7 mg/L for Daphnia magna.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.78 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 - 21 Nov 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1035 (Mysid Acute Toxicity Test)

Version / remarks:

draft

Qualifier:

according to guideline

Guideline:

other: FIFRA Guideline 72-3

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.13, 0.22, 0.36, 0.60 and 1.0 mg a.i./L measured at test initiation and termination

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A 20 mg a.i./L diluter stock solution was prepared daily by adding approximately 0.2532 g (0.1810 g as active ingredient) of OPP/SOPP to approximately 1 L of dilution water, and subsequently diluting to a final volume of 9.0 L with dilution water. Following approximately five minutes of mixing, the resulting stock solution was observed to be clear and colorless with no visible undissolved test substance present.

Test organisms (species):

Americamysis bahia (previous name: Mysidopsis bahia)

Details on test organisms:

TEST ORGANISM
- Common name: Mysid
- Source: bred at testing facility (originally obtained from Aquatic BioSystems, Inc., Colorado)
- Age of parental stock (mean and range, SD): < 24 h


ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): same
- Type and amount of food: fed brine shrimp (Artemia salina) nauplii, ad libitum
- Feeding frequency: twice daily

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

19 - 25 °C

pH:

8.1 - 8.3

Dissolved oxygen:

7.3 - 8.6 mg/L

Salinity:

20 to 22‰

Nominal and measured concentrations:

Nominal test substance concentrations: 0.13, 0.22, 0.36, 0.60 and 1.0 mg a.i./L
Mean measured test substance concentrations: 0.071, 0.16, 0.25, 0.44 and 0.80 mg a.i./L (% of nominal: 55, 71, 71, 73 and 80%)

Details on test conditions:

TEST SYSTEM
- Test vessel: square glass battery jars with two, 2-cm holes drilled approximately 15 cm from the bottom of each jar and covered with 40-mesh Nitex® screen for drainage.
- Material, size, headspace, fill volume: Glass, total volume 1.6 L, fill volume 1.4 L
- Type of flow-through (e.g. peristaltic or proportional diluter): intermittent-flow proportional diluter (Mount and Brungs. 1967)
- Renewal rate of test solution (frequency/flow rate): 90% test solution replacement rate of approximately six hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 0.72 mysids per litre/day

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: artificial seawater prepared from the addition of commercially available marine salts to well water to provide a salinity of20 ± 3%o. The dilution water used had a salinity of20 to 22%0 and a pH of8.l to 8.2

OTHER TEST CONDITIONS

- Photoperiod: 16 hours light, 8 hours darkness
- Light intensity: 740 to 1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
mortality, abnormal behavior or appearance of the test organisms every 24 h

RANGE-FINDING STUDY
- Test concentrations:
First test (24 h static): 0.05, 0.5 and 5.0 mg a.i./L.
Second test (96 h flow through) exposing both< 24-hour old and juvenile (5- to 6-day old) mysids: 1.0, 1.7, 2.9, 4.8 and 8.0 mg a.i./L
- Results used to determine the conditions for the definitive study:
First test (24 h static): 100% mortality at 5.0 mg a.i./L , 5% at 0.5 mg a.i./L.
Second test (96 h flow through): 100% mortality at 2.9, 4.8 and 8.0 mg a.i./L (< 24-hour old and juvenile (5- to 6-day old) mysids); 20% and 30% at 1.7 mg a.i./L for < 24-hour old and 5- to 6-day old mysids, respectively.
A series of exposures were required to establish test conditions which would maximize the stability of the test substance concentrations during the 96-hour exposure, the exposure condictions for the definitve test were chosen based on the results of the exposure series

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.32 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: Confidence interval: 0.26 - 0.42 mg a.i./L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.071 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other:

Remarks:

sublethal effects

Details on results:

Following 96 hours of exposure, 5, 10, 20, 75 and 100% mortality was observed among mysids exposed to the 0.071, 0.16, 0.25, 0.44 and 0.80 mg a.i./L treatment levels, respectively. Although mortality of 5% was observed in the lowest treatment level tested (0.071 mg a.i./L), this is considered to be within the expected range of naturally occurring variability for acute tests and not toxicant-related. No mortality or sublethal effects were observed among mysids exposed to the control.

Reported statistics and error estimates:

Statistics were performed using a computer program (Stephan, 1982) comprising the statistical methods moving average angle analysis, probit analysis and binomial probability.

Mean measured concentrations tested, corresponding mortalities and observations made during the 96-hour flow-through exposure of mysids (Americamysis bahia) to OPP/SOPP.

Cumulative mortality [%]
Mean Measured Concentration [mg a.i./L]	Replicate	0-Hour	24 -Hour	48-Hour	72-Hour	96-Hour
Control	A	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
	B	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
	Mean	0	0	0	0	0
0.071	A	0 (0)	0 (0)	0 (0)	10 (1)	10 (1)
	B	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
	Mean	0	0	0	5	5
0.16	A	0 (0)	0 (0)	0 (0)	10 (1)	20 (2)
	B	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
	Mean	0	0	0	5	10
0.25	A	0 (0)	0 (0)	0 (0)	0 (0)	10 (1)
	B	0 (0)	0 (0)	0 (0)	20 (2)	30 (3)
	Mean	0	0	0	10	20
0.44	A	0 (0)	0 (0)	30 (3)	60 (6)	60 (6)
	B	0 (0)	0 (0)	60 (6)	80 (8)	90 (9)
	Mean	0	0	45	70	75
0.80	A	0 (0)	40 (4)	90 (9)	90 (9)	100 (10)
	B	0 (0)	10 (1)	100 (10)	100 (10)	100 (10)
	Mean	0	25	95	100	100

    

Description of key information

Freshwater: LC50 (48 h): 2.7 mg a.i./L (nominal); read across

Marine water: LC50 (96 h) of 0.32 mg a.i./L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.7 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.32 mg/L

Additional information

One study on the acute toxicity sodium 2-biphenylate (CAS 132-27-4) to the marine mysid Americamysis bahia is available. To assess the acute toxicity of the substance to freshwater invertebrates a read across to the analogue substance 2-phenylphenol (CAS 90-43-7) as part of a read across approach, was conducted. The approach is in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. Further justification is given within the overall summary chapter 6.1 and within the analogue justification in IUCLID section 13.

The acute toxicity of sodium 2-biphenylate to Americamysis bahia was determined in a flow-through test design using artificial seawater as test medium. The test followed guideline EPA OPPTS 850.1035 and was conducted with GLP compliance. The mysids were exposed for 96 hours to nominal substance concentrations of 0.13, 0.22, 0.36, 0.60 and 1.0 mg a.i./L. The test solutions were replaced at a rate of 90% every 6 hours. The test substance concentration was analytically verified at test initiation and test termination. The mean measured concentrations were 0.071, 0.16, 0.25, 0.44 and 0.80 mg a.i./L (55, 71, 71, 73 and 80% of nominal). Based on the arithmetic mean meas. concentrations a LC50 (96 h) of 0.32 mg a.i./L was determined (Hoberg, 2006d).

The acute toxicity of the source substance 2-phenylphenol (CAS 90-43-7) to Daphnia magna was tested in a guideline study following ASTM Guideline Standard E729-80.Daphnia magna were exposed to nominal concentrations of 0.78, 1.3, 2.2, 3.6, 6.0, 10.0 mg/L in a static test design. The test substance concentration was analytically verified at test initiation and test termination. Due to recovery rates of 92 – 100% the effect concentrations were based on nominal concentrations. The LC50 value after 48 h was determined to be 2.7 mg a.i./L (nominal) (Dill et al., 1985).