tris (4-nonylphenol, branch) phosphorous acid ester

Sediment toxicity

Administrative data

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 December 2007 to 18 January 2008

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 225: Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment

Deviations:

yes

Remarks:

The light intensity was measured to be 436 to 680 lux, which was within the range of tolerance for this organism.

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 substrate

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT- Pooling or mixing of different substrates: artificial sediment (Springborn Smithers Batch No. 112107), 1.2 kg sphagnum peat, 4.0 kg kaolinclay, 7.4 kg fine sand and 7.4 kg of coarse sand (i.e., 6.0, 20, 37 and 37%, respectively).- Method of mixing: blended in a large-scale laboratory mixer- Details of spiking: Each test concentration was prepared by directly adding the appropriate amount of dosing stock solution to 0.050 kg of fine silica sand. The solvent was allowed to evaporate off for 20 minutes prior to adding the sand to 1.0 kg of sediment. The sediment/sand mixture was mixed for 15 minutes in a Hobart mixer.- Equilibration time: The spiked sediment and overlying water were added to the test vessels three days prior to addition of the test organisms (day -3).- Controls: A solvent control sample was prepared in the same manner as the treated sediment by adding 10 mL of acetone, containing no test substance, to 0.050 kg of fine silica sand and the solvent was allowed to evaporate off. The dried sand was then added to 1.0 kg of wet sediment and processed in the same manner as the treated sediments. The negative control sediment group was prepared using only untreated sediment and overlying water (no test substance or solvent). The control and solvent control vessels were maintained under the same conditions as the treatment vessels.- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone- Concentration of vehicle in test medium (stock solution and final test solution): 10 mL of acetone- Evaporation of vehicle before use: The solvent was allowed to evaporate off for 20 minutes prior to adding the silica sand to 1.0 kg of sediment.

Test organisms

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM- Common name: oligochaete- Source: Springborn Smithers main laboratory cultures - Details on collection: Ten to eleven days prior to test initiation, worms from the main culture were removed and artificially fragmented using a scalpel to remove the anterior ends. - Age of animals at beginning of exposure: Synchronized- Feeding during test - Food type: urtica powder and alpha cellulose - Amount: 2.10 g each - Frequency: 1x, mixed into the sediment prior to initiation ACCLIMATION- Acclimation period: ten to eleven days to regenerate new heads- Feeding during acclimation: 10 mL of finely ground suspension (10 mg/mL) of flaked fish food- Feeding frequency: 3x weekly

Study design

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

no

Exposure duration

Duration:

28 d

Exposure phase:

total exposure duration

Test conditions

Hardness:

150 mg/L as CaCO3 on Day 076 mg/L as CaCO3 on Day 28

Test temperature:

18 to 21°C

pH:

7.8 to 8.2

Dissolved oxygen:

7.7 to 9.1 mg/L

Salinity:

N/A

Ammonia:

Ranged from ≤0.10 mg/L as N to 0.87 mg/L as NA decrease in overlying water ammonia levels was observed during the final week of the study in the 1000 mg/kg treatment level. This may be a result of reduced sediment burrowing activity by the oligochaetes.

Nominal and measured concentrations:

Nominal: 63, 130, 250, 500 and 1000 mg a.i./kg

Details on test conditions:

TEST SYSTEM- Test container (material, size): 600-mL clear glass beakers- Sediment volume: 75-mL (1.5-cm layer) aliquot- Weight of wet sediment with and without pore water: 132 g (104 g dry weight)- Overlying water volume: 300 mL (6 cm)- Depth of sediment and overlying water: ratio of sediment to water was 1:4- Aeration: yes- Aeration frequency and intensity: 1 to 3 bubbles/second- Replacement of evaporated test water, if any: None, however, the initial water level in each test vessel was marked in order to evaluate evaporation. Each test vessel was covered with a clear plastic plate to minimize evaporation.EXPOSURE REGIME- No. of organisms per container (treatment): 10- No. of replicates per treatment group: 4- No. of replicates per control / vehicle control: 6- Feeding regime: once, at initiation- Type and preparation of food: urtica powder and alpha cellulose were mixed into the sediment of each test group- Amount of food: 2.10g each RENEWAL OF OVERLYING WATER- Details on volume additions: N/A- Flow-rate: N/AOVERLYING WATER CHARACTERISTCS- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): fortified laboratory well water- Source of water (if non-standard medium) - Location: laboratory well - Description of sampling site: routine water contaminant screening analyses were conducted using standard U.S. EPA procedures by GeoLabs, Inc., Braintree, Massachusetts. - Filtration: amberlite XAD-7 resin column - Alkalinity: 100 mg/L as calcium carbonate (CaCO3)- Salinity: N/A- Conductivity: 500 micromhos per centimeter (μmhos/cm)- Total organic chlorine compounds and PCBs: none detected at concentrations that are considered toxicCHARACTERIZATION OF ARTIFICIAL SEDIMENT- % dry weight of sphagnum moss peat: 6.0- Particle size distribution - % sand: 74 - % silt: 0 - % clay: 20- Composition (if artificial substrate): 1.2 kg sphagnum peat, 4.0 kg kaolin clay, 7.4 kg fine sand and 7.4 kg of coarse sand- Method of preparation (if artificial substrate): Prepared according to OECD Guideline No. 225 by blending the dry components together in a large-scale laboratory mixer.- Maturation of artificial substrate (if any): The sediment was added to the test vessels three days prior to test initiation.- Colour/texture: particle size distribution of 75% sand, 6% silt and 19% clay- Moisture: 11.8%- Presence of macrophytes/animals: none reported - Sediment sieved: no- pH dry matter and/or whole sediment: 6.3- Total organic carbon (%): 1.8%- Proof of absence of chemical contaminants: Periodic analyses of representative samples of of the artifical sediment were conducted using standard U.S. EPA procedures by GeoLabs, Inc., Braintree, Massachusetts. Conducted to ensure the absence of potential toxicants, including pesticides, PCBs, and selected toxic metals at concentrations that may be harmful to oligochaetes. OTHER TEST CONDITIONS- Light quality: fluorescent bulbs- Photoperiod: 16 hours light and 8 hours darkness- Light intensity: 440 to 680 luxEFFECT PARAMETERS MEASURED (with observation intervals if applicable): Daily observations of mortality and abnormal behavior (e.g., leaving sediment) were made and recorded.VEHICLE CONTROL PERFORMED: yesTEST CONCENTRATIONS- Spacing factor for test concentrations: 50% of the next higher concentration of the test substance

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

< 63 other: mg a.i./kg

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

and biomass

Effect concentrations 2

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

63 other: mg a.i./kg

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

and biomass

Effect concentrations 3

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

44 other: mg a.i./kg

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Effect concentrations 4

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

25 other: mg a.i.kg

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: biomass

Details on results:

- Mortality of test animals at end of exposure period: At test termination (day 28), the number of oligochaetes not recovered within the 63, 130, 250, 500 and 1000 mg a.i./kg treatment levels was 19, 21, 26, 25 and 28, respectively.- Total mass of test animals at beginning of test: Not reported, however, at conclusion of test, mean biomass of the pooled control organisms was 30 mg- Biomass at end of exposure period: Mean biomass in the 63, 130, 250, 500 and 1000 mg a.i./kg treatment levels was 20, 21, 15, 15 and 8.7 mg, respectively.- No. of offspring produced: average population increase factors in the 63, 130, 250, 500, and 1000 mg a.i./kg treatment groups was 2.0, 1.9, 1.3, 1.5, and 1.1, respectively. The population increase factor in the control was 2.6. - Behavioural abnormalities: none, however, turbidity of the overlying water caused by oligochaete burrowing activity made accurate observations of the test organisms difficult.

Reported statistics and error estimates:

Statistical analysis (Bonferroni’s t-Test) determined a significant difference in number of total oligochaetes recovered in all treatment levels testedcompared to the pooled control organisms (25 oligochaetes).Statistical analysis (Bonferroni’s t-Test) determined a significant difference in mean biomass in all treatment levels tested compared to the pooled control organisms (30 mg).

Any other information on results incl. tables

Table 1. Nominal sediment concentrations, number of oligochaetes and biomass of oligochaetes at test termination of the 28‑day exposure with TNPP and oligochaetes (Lumbriculus variegatus).

Nominal Sediment Concentration (mg a.i./kg)	Replicate	LCW^a	CW^a	IW^a	Total Number of Oligochaetes	Population Increase Factor	Biomass (mg)	Mean Number Of Oligochaetes per Replicate (SD^b)	Mean Biomass per Replicate per Concentration in Milligrams (SD)
Control	A	16	10	0	26	2.6	34.86	27 (1.9)	28.11 (5.39)
	B	9	18	0	27	2.7	18.95
	C	11	18	0	29	2.9	29.09
	D	12	12	0	24	2.4	28.61
	E	13	12	0	25	2.5	25.91
	F	11	17	0	28	2.8	31.21
Solvent Control	A	13	11	0	24	2.4	37.02	24 (2.6)	32.28 (4.82)
	B	11	13	0	24	2.4	36.52
	C	12	8	0	20	2.0	25.94
	D	10	15	0	25	2.5	27.57
	E	14	14	0	28	2.8	30.95
	F	11	13	0	24	2.4	35.70
Pooled Control								25 (2.5)	30.19 (5.34)
63	A	7	13	0	20	2.0	22.00	21 (1.5)^c	19.79 (6.36)^c
	B	9	11	2	22	2.2	22.48
	C	9	13	0	22	2.2	24.30
	D	7	12	0	19	1.9	10.36
130	A	9	8	0	17	1.7	19.04	19 (1.8)^c	20.86 (4.29)^c
	B	7	11	0	18	1.8	19.99
	C	11	9	0	20	2.0	27.08
	D	10	11	0	21	2.1	17.32
250	A	10	6	0	16	1.6	17.41	14 (2.5)^c	15.08 (6.42)^c
	B	11	3	0	14	1.4	17.30
	C	9	1	0	10	1.0	5.64
	D	11	3	0	14	1.4	19.98
500	A	10	2	0	12	1.2	20.02	15 (2.6)^c	14.98 (4.19)^c
	B	8	8	0	16	1.6	14.89
	C	9	9	0	18	1.8	15.23
	D	8	6	0	14	1.4	9.77
1000	A	9	0	0	9^d	0.9	5.34	12 (2.1)^c	8.66 (5.73)^c
	B	9	5	0	14	1.4	6.64
	C	11	1	0	12	1.2	17.20
	D	9	2	0	11	1.1	5.45

^a     LCW = Large, complete worms; CW = Complete worms; IW = Incomplete worms

^b      SD = Standard Deviation

^c      Statistically different (p ≤ 0.05) compared to the pooled control data, based on Bonferroni’s t-Test.

^d     Missing individual was assumed to be dead.

Applicant's summary and conclusion

Conclusions:

The EC10 values were 44 mg/kg ww and 25 mg/kg ww in sediment for TNPP.

Executive summary:

The EC10 values were 44 mg/kg ww and 25 mg/kg ww in sediment for TNPP.