tris (4-nonylphenol, branch) phosphorous acid ester

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 December 2008 to 21 January 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline, GLP study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-(2-methyloctyl)phenyl bis(4-nonylphenyl) phosphite

EC Number:

701-028-2

Cas Number:

26523-78-4

Molecular formula:

C45H69O3P

IUPAC Name:

4-(2-methyloctyl)phenyl bis(4-nonylphenyl) phosphite

Constituent 2

Reference substance name:

Nonylphenol

EC Number:

246-672-0

EC Name:

Nonylphenol

Cas Number:

25154-52-3

IUPAC Name:

2-nonylphenol

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

- Method: the test concentration was prepared at test initiation and at each renewal interval (i.e., every 24 hours)- Controls: dilution water control, solvent control- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): Stock Solution: 1.0 mg/mL, containing 0.0102 g of TNPP to 10 mL of acetone Controls: dilution water control vessels contained dilution water only, solvent control, containing 0.40 mL of acetone, 4.0 L of dilution water. Final Test Solution: A 0.10 mg/L water accommodated fraction (WAF): 0.40 mL of the 1.0 mg/mL primary stock solution, 4.0 L of dilution water. - Evidence of undissolved material (e.g. precipitate, surface film, etc): None

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Common name: Water Fleas- Source: Springborn Smithers Laboratories culture- Age of parental stock (mean and range, SD): < 24 hours old- Feeding during test0 to 6 days old: 1.0 mL of algae and 0.5 mL of YCT suspension per vessel per day. 7 to 10 days old: 1.5 mL of algae and 0.5 mL of YCT suspension per vessel per day> 10 days old: 2.0 mL of algae and 0.5 mL of YCT suspension per vessel per day. METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: All immature daphnids will be removed from the culture vessel to isolate sexually mature daphnids 24 hours prior to initiating the test. Young produced by these organisms were subsequently pipetted into the test beakers.

Study design

Test type:

other: static, daily renewal

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Test conditions

Hardness:

160 to 170 mg/L

Test temperature:

18 to 22 ºC

pH:

8.0 to 8.2

Dissolved oxygen:

7.8 to 9.5 mg/L

Nominal and measured concentrations:

100% water accommodated fraction (WAF) prepared from a 0.10 mg/L stock solution.

Details on test conditions:

TEST SYSTEM- Test vessel: beakers - Material, size, headspace, fill volume: 100-mL, clear glass - Renewal rate of test solution (frequency/flow rate): At test initiation and at 24-hour intervals- No. of organisms per vessel: one daphnid per replicate test vessel- No. of vessels per concentration (replicates): 30- No. of vessels per control (replicates): 30- No. of vessels per vehicle control (replicates): 30- Biomass loading rate: 0.20 mg carbon/daphnid/day TEST MEDIUM / WATER PARAMETERS- Source/preparation of dilution water: fortified well water, used the formula for hard water (U.S. EPA, 1975) and filtered through an Amberlite XAD 7 resin column to remove any potential organic contaminants - Total organic carbon: 0.69 and 0.37 mg/L- Metals: None of these compounds have been detected at concentrations that are considered toxic in any of the water samples analyzed, in agreement with ASTM (2002) standard practice.- Pesticides: None of these compounds have been detected at concentrations that are considered toxic in any of the water samples analyzed, in agreement with ASTM (2002) standard practice.- Alkalinity: 98 to 100 mg/L- Conductivity: 500 to 550 micromhos per centimeter (µmhos/cm)- Culture medium different from test medium: no- Intervals of water quality measurement: Dissolved oxygen, temperature and pH were measured in the test solution and controls at the beginning (new solutions) and end (aged solutions) of each renewal period. Temperature of the water bath containing the test vessels was continuously monitored. Total hardness, alkalinity and specific conductance were measured and recorded in the freshly prepared solution of the nominal test concentration and the control at test initiation and weekly thereafter. On day 21 (test termination), all measurements were taken from aged solutions.OTHER TEST CONDITIONS- Photoperiod: 16 hours of light, 8 hours of darkness- Light intensity: 8.6 to 13 µE x m-2 x s-1 EFFECT PARAMETERS MEASURED (with observation intervals if applicable): The number of immobilized adult daphnids and observations of abnormalbehavior were recorded daily. Numbers of offspring were determined upon the first brood release in any vessel, day 8, and daily throughout the remainder of the test. In addition, the number of immobilized offspring and the time to first brood release were recorded for the treatment level and the controls. Observations of physical characteristics of test solutions (e.g., precipitate, cloudy solution) were recorded whenever the test organisms were observed. VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

21 d

Dose descriptor:

LL50

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

and survival

Remarks on result:

other: 100% WAF

Effect concentrations 2

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

survival, and growth

Remarks on result:

other: 100% WAF

Effect concentrations 3

Duration:

21 d

Dose descriptor:

LOELR

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

survival, and growth

Remarks on result:

other: 100% WAF

Details on results:

- Mortality of parent animals: 3%- No. of offspring produced per per female: 272- Body length of parent animals: 5.40 mm - Day of first brood release: Test day 8

Reported statistics and error estimates:

The coefficient of variation for the control fecundity was 8.1%. Statistical analysis (Wilcoxon’s Rank Sum Test) determined no significant reduction in cumulative offspring per female among daphnids exposed to the treatment level tested compared to the solvent control data (i.e., 258 offspring/female). Wilcoxon’s Rank Sum Test determined no significant difference in total body length among daphnids exposed to the treatment level tested comparedto the pooled control data (i.e., 5.31 mm).

Any other information on results incl. tables

Based on survival, reproduction and growth, the 21‑day NOEC for TNPP and D. magna was determined to be 100% WAF of a 0.10 mg/L stock solution. The 21-day LOEC was determined to be > 100% WAF of a 0.10 mg/L stock solution.

Since no concentration tested resulted in≥50% immobilization or reduction in reproductive output, the EC50 values for both survival and reproduction were empirically estimated to be > 100% WAF of a 0.10 mg/L stock solution.

Additional testing to further define the EC50 value was not conducted since the nominal concentration tested is considered to be representative of the functional solubility limit of the test substance under the test conditions maintained.

Table 1. The nominal concentrations tested, mean survival, reproduction and total body length of parental daphnids (Daphnia magna) during the 21-day chronic exposure to TNPP.

 

Nominal Concentration	Mean Percent Survival	Mean (SD)^aNumber of Offspring Released	Mean (SD)^a Total Body Length (mm)
Control	93	268 (22)	5.31 (0.16)
Solvent Control	97	258 (16)	5.31 (0.12)
100 % WAF of a 0.10 mg/L stock solution	97	272 (15)	5.40 (0.10)

 

^a      SD = Standard Deviation.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

There were no signs of effects on growth or reproductive toxicity in daphnia magna in this 21-day study of TNPP run at maximum loading level of 0.1mg/L (double the estimated water solubility limit).

Executive summary:

There were no signs of effects on growth or reproductive toxicity in daphnia magna in this 21-day study of TNPP. The NOEC is 0.1 mg/L (nominal) and the LOEC and EC50 are >0.1 mg/L (nominal).