1-(2-hydroxy-5-nonyl(branched)-phenyl)ethanone oxime

Sediment toxicity

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 225 (Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment)

Version / remarks:

2007

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Appearance: light yellow / light yellow to slightly greenish, clear, high viscous liquid
- Source and lot/batch No.of test material: 19.04.2017
- Expiration date of the lot/batch: 19 Apr 2022
- Purity test date: 100% UVCB

Analytical monitoring:

yes

Details on sampling:

The test item concentrations and the controls were confirmed by analytical verification via UPLC-MS/MS on day 0, 7 and 28 using additional replicates, each. Determination of the test item was performed for the sediment, pore water and the overlying water in the controls and all test item concentrations under GLP.

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Method of mixing: The respective test item amount was weighed out for a stock solution and dissolved in Acetone. The stock solution was further diluted with Acetone to receive the respective spiking solutions. The appropriate amount of spiking solution (2.5 mL per replicate) was thoroughly mixed with a subset of the artificial sediment (10 g per replicate). After complete evaporation of the solvent, the spiked portion of artificial sediment was thoroughly mixed with the remaining sediment. Demineralised water was added to the artificial sediment to adjust the humidity of the artificial sediment to a moisture of 30 %. Subsequently, the test medium was thoroughly mixed to ensure a homogenous distribution.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Evaporation of vehicle before use: yes

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM
- Source: Bundesanstalt für Gewässerkunde (BfG), Koblenz, Germany
- Breeding conditions: Breeding is performed at the test facility at 20  2 °C and diffuse light (100 - 500 lx, 16 h photoperiod daily). The dissolved oxygen concentration is > 70 % of the air saturation value corresponding to 6.2 mg O2/L. Breeding of L. variegatus is performed on quartz sand in reconstituted water containing 125 mL from each stock solution poured in a can and filled up to 25 L with demineralised water.
- Age of animals at beginning of exposure: The worms were synchronized 14 days prior to insertion to minimize uncontrolled reproduction and regeneration. Synchronization was achieved by artificial fragmentation of large healthy worms.
- Feeding during test
- Food type: Powder of Urtica dioica (stinging nettle, HEINRICH KLENK GMBH & CO KG, 97525 Schwebheim, Germany) was mixed into the sediment at the day of application.
- Amount: 0.4 % of the sediment dry weight

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Hardness:

370 - 404 mg/L as CaCO3 (test start)
371 - 450 mg/L as CaCO3 (test end)

Test temperature:

19.2 - 22.2 °C

pH:

7.32 - 7.90

Dissolved oxygen:

7.27 - 9.09 mg/L (> 70%$ saturation)

Nominal and measured concentrations:

Nominal: 1.0, 3.2, 10, 32 , 100 and 320 mg/kg soil dry weight

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 250 mL glass beakers (6 cm diameter)
- Sediment volume: 45 g dry weight per vessel
- Overlying water volume: 150 mL
- Depth of sediment and overlying water: ca. 1.0 - 3.0 cm from the ground
- Aeration: yes
- Aeration frequency and intensity: Gentle aeration via Pasteur pipettes. Aeration was checked at least each working day.
- Replacement of evaporated test water, if any: Water levels were topped up with demineralised water at least each working day during the study to compensate losses due to evaporation, therefore water levels did not change by more than 10 %.

EXPOSURE REGIME
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control / vehicle control: 6
- Type and preparation of food: Powder of Urtica dioica (stinging nettle, HEINRICH KLENK GMBH & CO KG, 97525 Schwebheim, Germany) was mixed into the sediment at the day of application.
- Amount of food: The amount was 0.4 % of the sediment dry weight.

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): reconsituted water acc. to guideline

CHARACTERIZATION OF ARTIFICIAL SEDIMENT
- % dry weight of sphagnum moss peat: 4.2%
- Composition (if artificial substrate): 20 % kaolin, with a kaolinite content > 30 %; 5 % quartz sand (> 50 % particles sized 50-200 µm); 0.40 % calcium carbonate (CaCO3) to achieve a pH of 6.62
- Moisture: 30 %
- Total organic carbon (%): 2.19%

OTHER TEST CONDITIONS
- Photoperiod: 16 h light, 8 h dark
- Light intensity: 100 - 500 lx

EFFECT PARAMETERS MEASURED: Visual observations of behavioural differences to the control were recorded three times per week. The endpoints of the study as determined after day 28 were the number of surviving worms per replicate and the total dry biomass of worms per replicate.

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

yes

Remarks:

Potassium chloride

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

32 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Mortality of test animals at end of exposure period: No mortality of worms was observed in the controls and the test item concentrations 1.0 to 100 mg/kg soil dry weight after exposure to the test item over 28 days. However, at the test item concentration 320 mg/kg soil dry weight a mortality of 2.5 % occurred after 28 days of exposure.
- Total biomass per replicate: At test start the worms had a body weight of 9.7 mg dry weight/10 worms (mean weight of two determinations). At test end, the mean biomass dry weight of the worms was not statistically significantly different at the test item concentrations 1.0 to 100 mg/kg soil dry weight compared to the pooled control. However, at the test item concentration 320 mg/kg soil dry weight the mean biomass dry weight of the worms was statistically significantly reduced
- Behavioural abnormalities: No evident changes in the worm behaviour or pathological symptoms were observed in the control as well as in the test item concentrations 1.0 to 32 mg/kg soil dry weight during the 28 days of exposure. However, at the test item concentrations 100 and 320 mg/kg soil dry weight worms on the soil surface were observed more often

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 = 2.17 – 4.31 mg/L
- EC50: 3.04 mg/L

Since no statistically significant difference was determined between the control and the solvent control, both controls were pooled for further evaluation.

Validity criteria fulfilled:

yes

Conclusions:

The test substance shows a NOEC value of 32 mg/kg sediment for reproduction at chronic exposure.

Reference 2

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Acceptable, well documented and peer reviewed publication which meets basic scientific. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance. The observed effects on the benthic community were most likely due to NP exposure from the water. Because pore water NP concentrations were low compared to overlying water concentrations, it is unlikely that effects observed on sediment-dwelling organisms (e.g., Chironomini, Tubificidae, and Bivalvia) were significantly influenced by sediment exposures. Therefore, the given NOEC for the benthic community of 23 µg/L is not considered to be relevant for the assessment of the toxicity of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0) to sediment dwelling organisms and thus this effect value was not used for the hazard assessment.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Field study investigating the effect of 4-nonylphenol on benthic freshwater macroinvertebrates in littoral enclosures over a 2-year period.

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

SEDIMENT
- Concentrations: Depth-integrated composite water samples for analysis of NP were collected from all treated enclosures and one randomly selected control enclosure 2 and 39 h after each application.
- Sampling interval: Sediment sampling followed methods described in Knuth and Heinis (1992). Containers (10 x 10 x 6 cm deep) filled with preapplication bulk sediment that had been sieved through a 6-mm-square screen were placed on the pond bottom within two enclosures (30 and 300 µg/L) 21 d before the initial NP application. After deployment at the field site, duplicate containers of sediment were collected on the same schedule as the plastic strips. Samples were stored on ice, transported to the laboratory, and stored frozen at -20 °C until extraction and analysis.
‘‘Natural’’ sediments were also collected from all treatment enclosures and three control enclosures every 2 weeks beginning 4 d after the final NP application. A box core grab sampler (16 x 16 x 25 cm deep) was utilized that contained a Plexiglas liner that could be removed without disturbing the sediment profile, prior to extrusion to isolate specific horizons. Rocks, sticks, and aquatic vegetation were removed from the top of the sample and the surficial 2 cm of sediment was transferred to a clean glass sample jar. Two sediment cores from each enclosure were combined to generate each sample. Samples were transported on ice to the laboratory and stored at 4 °C until processing on the next day. Samples were homogenized for 3 to 5 min using a stainless-steel propeller on a handheld power drill. Aliquots were removed for analysis of dry weight and total organic carbon (TOC) and the remainder was stored at -20 °C until NP analysis.

OVERLYING WATER
- Concentrations: Depth-integrated composite water samples for analysis of NP were collected from all treated enclosures and one randomly selected control enclosure 2 and 39 h after each application.
- Sampling interval: Composite samples consisted of five subsamples, one taken near each corner of the enclosure, 0.5 to 1 m from the side walls and one taken at the center of the enclosure. Additional samples, to better characterize the NP loss between subsequent applications, were collected at 12 and 24 h in one 30 µg/L enclosure and in one 300 µg/L enclosure following applications 1 and 3 and in one 3 µg/L enclosure and in one 100 µg/L enclosure following applications 5 and 7. Following application 11, all treated enclosures were sampled at 2, 16, and 24 h, and at 2, 5, and 7 d. Samples were taken weekly from 7 d through 63 d and every second week from 63 d through 98 d (November 4, 1993). A final set of samples was taken on day 313 (June 7, 1994).
To assess the within-enclosure variability in NP concentration, the five subsamples that normally would constitute a composite sample were analyzed separately in a 100 µg/L enclosure at 2 and 39 h after application 10. In addition, samples were taken at 2, 12, 24, and 39 h after application 10, and
vertical homogeneity was evaluated by collecting top and bottom water samples, 18 cm below the water surface and 10 cm above the sediment surface, respectively. Each top and bottom sample consisted of three subsamples removed from the deep end of the enclosure (0.5–1.0 m from the end wall) and combined into a single composite for analysis. Strips of enclosure wall material (1 x 30 cm) were suspended in the enclosures 21 d before NP application began for subsequent sampling to estimate NP adsorption to the enclosure walls. Strips were collected 2, 8, 14, and 20 d after the initial NP application. After the final NP application, strips were collected at 1, 2, 4, and 7 d, weekly through 28 d, every second week through 56 d, and on 298 and 420 d. The strip samples were stored on ice, transported to the laboratory, and stored at -20 °C until extraction and analysis.

SUBMERGED MACROPHYTES
Submerged macrophytes, predominately Chara sp., were collected using a grab technique with the same schedule as the plastic strips above. The area sampled was approximately 360 cm2 per grab sample. One shallow grab (less than mean water depth) and one deep grab (greater than mean water
depth) were collected, drained of excess water, combined, placed into a wide-mouth glass jar, transported on ice to the laboratory, and stored at -20 °C until extraction and analysis.

Vehicle:

no

Details on sediment and application:

Eleven applications of NP, each 2 d apart, were made to the littoral enclosures. Each application was made at 125% of nominal, as an aqueous stock
solution, approximately 20 to 120 cm below the water surface through a 6-mm inner diameter (i.d.) teflon tube attached to a 2-m-long wooden paddle. The paddle was used to mix the NP gently into the enclosure throughout the application. Applications began on July 8, 1993 at 16:00 h central daylight time (CDT) and ended on July 28, 1993 at 18:00 h CDT.
The mean reapplication rate was 77.0 ± 8.4% (coefficient of variation [CV] = 10.9%). The average (±SD) mass of NP added to the treated enclosures was 0.068 ± 0.036, 0.085 ± 0.132, 3.40 ± 0.85, and 10.04 ± 2.37 g at treatments of 3, 30, 100, and 300 µg/L, respectively.

Test organisms (species):

other: benthic macroinvertebrate community

Details on test organisms:

A total of 25 taxa were identified from the core samples, but the community was dominated by three major groups: Chironomidae, Oligochaeta, and Mollusca.

Study type:

field study

Test type:

other: Enclosures received 11 NP applications, 48 h apart (= 20 d application period)

Water media type:

freshwater

Type of sediment:

natural sediment

Limit test:

no

Duration:

104 wk

Exposure phase:

total exposure duration

Nominal and measured concentrations:

Nominal: 3, 30, 100 and 300 mg/L

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 2 ha mesotrophic pond near the city of Duluth, MI, USA (see free text)

EXPOSURE REGIME
- No. of replicates per treatment group: 3
- No. of replicates per control: 6

OVERLYING WATER CHARACTERISTCS
- Type of water: 2 ha mesotrophic pond near the city of Duluth, MI, USA (see free text)

SOURCE OF NATURAL SEDIMENT
- Location and description of sampling site: 2 ha mesotrophic pond near the city of Duluth, MI, USA (see free text)

EFFECT PARAMETERS MEASURED: Abundance and emergence of Chironomidae, Oligochaeta and Mollusca were recorded at day 2, 8, 14, 20, 21, 22, 24, 27, 34, 48, 76, 318, 353 and 440.

Reference substance (positive control):

no

Duration:

104 wk

Dose descriptor:

NOEC

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: abundance

NP chemistry

Peak exposure of aquatic organisms to NP during the application period was estimated by calculating the 20-d average NP concentration in the integrated water column 2 h after each application. Mean ( ± SD) peak concentrations were 5 ± 4, 23 ± 11, 76 ± 21, and 243 ± 41 mg/L NP at nominal treatments of 3, 30, 100, and 300 mg/L, respectively. There was a 61 ± 3% loss of NP from the water column within 39 h of each application. Half-lives following the final application were estimated at <= 1 d. Nonylphenol concentrations in sediment and macrophytes generally increased during the application period and peaked at or shortly after the last application. Maximum measured concentrations in sediment and macrophytes in one 300 µg/L enclosure were 27.4 and 114 mg/kg dry weight, respectively. Persistence of NP in sediment and macrophytes was substantially longer than in the water, with quantifiable residue levels in 300 µg/L enclosures detected for >= 318 d.

Taxa affected by NP

Oligochaeta

A significant (90%) reduction in Naididae was recorded at 300 µg/L on the first sampling date (day 25) following the application period. Large reductions were also recorded on days 39 (82%) and 53 (54%), but these were not statistically different from the controls. The Naididae increased in abundance to greater than control levels by day 75 and remained higher for the duration of the study. There were no significant changes in naidid abundance at NP treatments <= 100 µg/L, but a 68% reduction was observed on day 25. This reduction was statistically significant when the data were standardized to correct for preapplication variability using a repeated-measures approach. This approach did not change interpretation of effects at the 300 µg/L treatment. Mean abundances of Tubificidae at the 100 and 300 µg/L treatments were 29 to 67% (day 25) and 71 to 86% (day 39) lower than mean control abundances. None of the differences were significant.

Mollusca

Bivalvia (Pisidium) were significantly reduced at 300 µg/L on most postapplication dates. Reductions ranged from 80 to 91%, with no recovery apparent. A significant reduction (87%) was also observed on day 299 at the 100 µg/L treatment. Reductions of 67% (day 25) and 56% (day 111) at 100 µg/L were not statistically significant. Gastropoda (Planorbidae) were significantly reduced by 88 to > 99% at 300 µg/L on days 25, 53, 75, and 111. Reductions of 43 to 58% were observed at 100 µg/L on the same days, but these differences were not statistically significant. Standardizing for preapplication variability did not change that result. Populations at the 300 µg/L treatment were similar to controls during the second year of sampling (days 299 and 399).

Chironomidae

An 81% reduction in Tanytarsini on day 25 at 300 µg/L was the only significant reduction in larval chironomids. A 75% reduction was observed on day 39 but was not statistically significant. Recovery to control levels occurred by day 53, followed by a 3.5-fold and 1.2-fold increase on days 75 and 111, respectively. The Chironomini were reduced by 49% (day 25) and 28% (day 39) at 300 µg/L. Populations recovered to control levels by day 53 and remained at control levels for the duration of the study. Standardizing for preapplication variability had no effect on statistical conclusions. There were no effects at the 100 µg/L treatment for either Tanytarsini or Chironomini. Populations of Tanypodinae and Orthocladiinae were consistently low throughout the study and effects of NP could not be assessed. Effects on chironomid emergence were very similar to effects seen for the larvae of Tanytarsini and larval chironomids as a group. Significant reductions of adults at the 300 µg/L treatment were observed on days 8 to 24. However, populations began to recover immediately after NP applications ceased and were comparable to control levels by days 33 and 45. A sevenfold increase in emergence was observed on days 62 and 78, and emergence remained higher than in controls for the duration of the assessment period. Emergence was not affected at the 100 µg/L treatment.

Conclusions:

A field study investigating the effect of 4-nonylphenol on benthic macroinvertebrates over a 2-year period determined a 2yr-NOEC value of 23 µg/L for the benthic community based on abundance and emergence.

Executive summary:

The effect of nonylphenol on sediment dwelling macroinvertebrates were investigated in a field study. Eleven applications of NP (branched isomers), each 48 h apart, were made to the littoral enclosures before recording abundance and emergence of relevant taxonomic groups. The 300 µg/L NP treatment significantly affected most macroinvertebrate groups evaluated, whereas the 100 µg/L NP treatment had possible minor effects on only Naididae and Gastropoda. The observed effects on the benthic community were most likely due to NP exposure from the water, although macrophyte-associated residues may have contributed to effects on Tanytarsini, Naididae, and Gastropoda. Therefore, macrophyte-associated NP residues may pose a small risk to benthic organisms, but it is probably minor compared to water exposures. Because porewater NP concentrations were low compared to overlying water concentrations, it is unlikely that effects observed on sediment-dwelling organisms (e.g., Chironomini, Tubificidae, and Bivalvia) were significantly influenced by sediment exposures. The NOEC and LOEC for the benthic community was 23 ± 11 and 76 ± 21 µg/L, respectively.

Reference 3

Endpoint:

sediment toxicity: long-term

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

see Analogue justification document in chapter 13

Reason / purpose for cross-reference:

read-across source

Limit test:

no

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

32 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Reference 4

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD guideline 225

Deviations:

yes

Remarks:

minor deviations are mentioned but not specified

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Method of mixing: 1g of the test substance was directly added to 250 g wet sediment (50% water content) and mixed with 250 mL of water. The mixture was mixed for 20 h and left to settle for 72 h. Sediment was then separated from water by centrifugation.
- Details of spiking: Spiked sediment generated by mixing stock sediment with reference sediment
- Controls: yes

Test organisms (species):

Tubifex tubifex

Details on test organisms:

TEST ORGANISM
- Source:on-site cultures started from adults collected in Lake Suviana, Italy
- Breeding conditions: kept in the dark at 21 °C in glass containers half filled with sterilized sand and dechlorinated tap water, 25 adults per beaker. Fed frozen spinach thawed to room temperature
- Details on collection: cocoons removed from sand every week
- Age of animals at beginning of exposure: approximately 6 weeks, at their first reproductive event
- Feeding during test: yes
- Food type: Tetramin during test
- Amount: 80 mg dry power/ test chamber
- Frequency: food mixed with sediment before test initiation

ACCLIMATION
- Acclimation period: none needed as cultured in lab

Study type:

laboratory study

Test type:

semi-static

Water media type:

freshwater

Type of sediment:

natural sediment

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Hardness:

320 mg/L as CaCO3

Test temperature:

21 ± 1 °C

pH:

not provided, but varied by 0.2 during test

Dissolved oxygen:

not provided, but test chambers were aerated for 2 h prior to test initiation, at test termination the saturation was 65%

Ammonia:

< 0.02 mg/L

Nominal and measured concentrations:

Nominal: Test 1: 0, 180, 380, 420, 460 and 650 mg/kg dw
Nominal: Test 2: 0, 90, 190, 310, 430, 610 mg/kg dw

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 250 mL glass beakers covered with petri dish
- Weight of wet sediment with and without pore water: 70 g 50% water
- Overlying water volume: 150 mL
- Aeration: yes- 2h before test and during test continuously
- Replacement of evaporated test water, if any: yes, every 2 days, if needed

EXPOSURE REGIME
- No. of organisms per container (treatment): 4
- No. of replicates per treatment group: 5
- No. of replicates per control / vehicle control: 5
- Feeding regime: at test initiation
- Type and preparation of food: Tetramin powder
- Amount of food: 80mg powdered food per chamber

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): dechlorinated tap water
- Temperature, pH, and DO were measured in all beakers before and at the end of the test.

SOURCE OF NATURAL SEDIMENT
- Location and description of sampling site: Lake Monate Northern Italy
- Contamination history of site: unpolluted sediment. Chemical analysis confirmed NP was not present and other parameters were in range of previous suggestions by Salomons and Forstner (1984)

HANDLING OF NATURAL SEDIMENT
- Water depth: 10 m
- Storage conditions: stored in the dark at 4 °C

OTHER TEST CONDITIONS
- test performed in the dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Adult survival, number of cocoons and young worms were assessed after 28 days exposure time. Qualitative observations included "reworking activity" and gonadal malformations.

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

335 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

number of young worms

Remarks on result:

other: 311.6 - 360.3 mg/kg, result of test 1; test 2 result: 382.8 mg/kg dw

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

336.7 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

number of cocoons

Remarks on result:

other: 295.0 - 384.4 mg/kg, result of test 1; test 2 result: 382.7 mg/kg dw

Details on results:

The production of cocoons and young worms per adult among the controls from both experiments was not significantly different. In both bioassays breeding adults started to die at 600 mg/kg dw. With increasing concentrations of 4NP in sediments, a reduced reworking activity in sediments of adult worms was observed based on decreased number of galleries. The decrease of adult worm health was supported by histological analyses of the clitellum area of Tubifex tubifex at two 4NP concentrations compared to those of the control. This analysis of Tubifex kept in control sediments revealed completely developed male and female gonads. Large spermatozeugmi were present in every spermatheca and a great number of paraspermatozoons and euspermatozoons could be observed in the spermatic sacs. Ovaries were well developed with several ovocytes. A similar situation was found in worms exposed to 190 mg/kg dw. Midges started to emerge after 14-16 days both in control and in treatments. The emergence period was more prolonged (8-10 days) for control and for organisms exposed to 290 mg/kg dw compared to that for the other treatments (4-6 days). The number of females seemed to be slightly greater than the number of males in the control beakers (55 and 55.5%, respectively), while the opposite was observed in presence of 4NP, where the number of males became higher than 60%. Nevertheless, the observed differences were not statistically significant.

Validity criteria fulfilled:

not specified

Executive summary:

The 28 day long-term toxicity test of nonylphenol to Tubifex tubifex was studied under semi-static conditions. Tubifex were exposed to 4-nonylphenol at nominal concentrations of 90 - 650 mg/kg sediment dw. The sublethal effects assessed included production of cocoons and young worms per adult. The most sensitive end point was number of young worms per adult. The lowest 28-day EC10 value is determined to be 335 mg/kg dw.

Reference 5

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

28d chronic sublethal sediment bioassay using the estuarine amphipod Leptocheirus plumulosus

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Details on sediment and application:

Sediment was collected from either CLIS (4l°08.040' N, 72°52.717' W) at a standard reference site used by the USEPA in toxicity testing or from Flax Pond (40°57.778' N, 73°08.216' W), a sparsely populated coastal inlet on the north shore of Long Island. A Ponar grab was used to remove the top 5 cm of sediment from the surface of each of four grabs and homogenized into a single composite sample. This was then sieved to 500 µm and stored for up to 1 year at 4 °C until use. Study references Fay et al (2000) for amending reference sediment with the test substance. Spiking solutions of toxicant were added to glass jars. Sediment and seawater were added to each jar to create a 50% sediment water slurry mix. Jars were shaken for 7 days on a shaker at 125 rpm. After 7 days, sediments were centrifuged to remove excess seawater and were homogenized.

Test organisms (species):

Leptocheirus plumulosus

Details on test organisms:

TEST ORGANISM
- Source: laboratory cultures
- Age of parental stock (mean and range, SD): < 2 weeks ols, juvenils
- Feeding during test: via available sediment

ACCLIMATION
- Acclimation period: none (lab culture)

Study type:

laboratory study

Test type:

static

Water media type:

saltwater

Type of sediment:

natural sediment

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Test temperature:

23 ± 1 °C

pH:

not specified

Dissolved oxygen:

not specified

Salinity:

20 ppt

Ammonia:

not specified

Nominal and measured concentrations:

Measured: 2.1, 4.5, 10.5, 27.2 and 61.5 mg/kg dw

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 250mL chamber
- Sediment volume: 50 mg
- Weight of wet sediment with and without pore water: 50g ww
- Overlying water volume: 200 mL
- Depth of sediment: 2cm

EXPOSURE REGIME
- No. of organisms per container (treatment): 15
- No. of replicates per treatment group: 5
- No. of replicates per control / vehicle control: 5
- Feeding regime: 3 times a week
- Type and preparation of food: "gorp" - mixture of TetraMin, dried alfalfa, wheat grass powder and shrimp maturation feed
- Amount of food: 1mg per organism

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): synthetic seawater
- Salinity: 20ppt

SOURCE OF NATURAL SEDIMENT
- Location and description of sampling site: "Flax Pond", a sparsely populated coastal inlet on north shore of Long Island
- Contamination history of site: used as reference site
- Total organic carbon (%): 2.6%

HANDLING OF NATURAL SEDIMENT
The top 5 cm were collected from surface of four grabs from Ponar grab and homogenized. Sediment was sieved to 500 um and stored for up to 1 year at 4 deg C until use.

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

EFFECT PARAMETERS MEASURED: At the end of the 28d exposure, the adults and juvenils were differentially sieved from the sediment and the number of young per surviving female was determined.

TEST CONCENTRATIONS
- Range finding study: Yes
- Test concentrations: 0, 62.5, 118.8, 200, 400 mg/kg
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 61.5 mg/kg sediment dw

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: and mortality

Details on results:

A significant negative correlation (P<0.034) was observed between NP sediment concentration and the number of young produced per female, but it explained only 12% of the variance. Reproductive output in animals exposed to 61.5 mg/g NP was reduced by 40% of control values, but this difference was not statistically significant (P=0.299).

Reported statistics and error estimates:

Reproductive output in the 28-d field sediment exposures was analyzed using a two-sample, two-tailed T-test after square root transformation to equalize variance.

Validity criteria fulfilled:

not specified

Remarks:

some information missing

Conclusions:

A 28d long-term toxicity test showed no significant effects of 4-nonylphenol to reproduction and mortality of the marine amphipod Leptocheirus plumulosus up to the highest tested concentration of 61.5 mg/kg sediment dw.

Executive summary:

A 28-day long-term toxicity test of 4-nonylphenol to the benthic crustacean, Leptocheirus plumulosus,was performed under static conditions. Crustaceans were exposed to control and 4-nonylphenol at average measured concentrations of 2.1, 4.5, 10.5, 27.2 and 61.5 mg/kg dw. A significant negative correlation (p < 0.034) was observed between 4 -nonylphenol sediment concentration and the number of young produced per female, but it explained only 12% of the variance. Reproductive output in animals exposed to 61.5 mg/g NP was reduced by 40% of control values, but this difference was not statistically significant (p = 0.299). Thus, the 28d-NOEC value is determined to be >= 61.5 mg /gg dw based on reproduction and mortality.

Description of key information

NOEC (28d) = 32 mg/kg sediment dw (nominal) for reproductive output of freshwater annelid Lumbriculus variegatus (OECD 225, read across)

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater sediment:

32 mg/kg sediment dw

Additional information

Since no study assessing the long-term toxicity of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0) to sediment organisms is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to the structurally very similar source substance Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched (CAS 174333-80-3), was conducted. The only structural difference between the source substance and the main component of the target substance is the lack of a methyl group at the oxime carbon of the source substance. The read across is justified due to (i) the similarity of structure and functional groups and accordingly (ii) similar physico-chemical properties resulting in a similar environmental fate and ecotoxicity profile (see table below).

Substance	Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched	Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched
CAS number	244235-47-0	174333-80-3
Structure	see attachment	see attachment
Molecular formula	C17H27NO2	C16O2NH25
Molecular weight	~ 277 g/mole	~ 263 g/mole
PC parameter
Water solubility	> 0.02 < 0.1 mg/L (EU method A.6)	0.4 mg/L (EU method A.6)
Partition coefficient	> 5.7 (EU method A.8)	5.5 (EU method A.8)
Vapour pressure	< 1.5 Pa at 20 °C (OECD 104)	0.37 Pa at 20 °C (OECD 104)
Environmental fate
Biodegradability	1 % in 28 days (BODIS)	0 % in 28 days (OECD 302c)
Adsorption [log KOC]	3.9 (OECD 121)	3.7 (OECD 121)
Hydrolysis	not relevant due to very low water solubility
Ecotoxicology
Short-term toxicity to fish [96h-LC50]	0.46 mg/L (EU method C.1)	1.1 mg/L (EU method C.1)
Short-term toxicity to aquatic invertebrates [48h-EC50]	-	2.7 mg/L (EU method C.2)
Long-term toxicity to aquatic invertebrates [21d-NOEC]	2.8 mg/L (OECD 211)	0.189 mg/L (OECD 211)
Short-term toxicity to algae [72h-EC50]	760 mg/L (OECD 201)	36.3 mg/L (OECD 201)
Long-term toxicity to algae [72h-NOEC]	472 mg/L (OECD 201)	14.9 mg/L (OECD 201)
Toxicity to microorganisms [3h-EC10]	260.1mg/L (OECD 209)	200.4 mg/L (OECD 209)

The study with the source substance was conducted according to GLP and OECD guideline 225 using Lumbriculus variegatus as test organism (Winkelmann 2019). Nominal concentrations between 1.0 and 320 mg/kg soil dry weight were tested. The test item concentrations and the controls were confirmed by analytical verification via UPLC-MS/MS on day 0, 7 and 28 using additional replicates, each. Determination of the test item was performed for the sediment, pore water and the overlying water in the controls and all test item concentrations. The measured concentrations of the peak groups B and C in the sediment were in the range from 80% to 98% at day 0, from 77% to 102% at day 7 and from 40 to 63% at day 28, compared to the respective recoveries of the peak groups during method calibration. Minor recoveries of the concentrations of the test item in the aqueous phase and pore water could be determined. Control and solvent control samples were < LOQ. Since the peak recoveries cannot easily be transferred into test substance concentrations, the effect values are related to the nominal concentration. No mortality of worms was observed in the controls and the test item concentrations 1.0 to 100 mg/kg soil dry weight, but at 320 mg/kg soil dry weight a mortality of 2.5 % occurred after 28 days of exposure. Based on reproduction a 28d-NOEC value is determined to be 32 mg /kg dw based.

This result is supported by sediment toxicity data available for 4-nonylphenol. Phenol, 4 -nonyl-,branched was considered, since is a secondary component (residual starting material) and structurally similar to the main component of the substance.

 Three long-term toxicity tests are available investigating the effect of 4-nonylphenol on the reproductive output on sediment dwelling organisms: A 28-day long-term toxicity test of 4-nonylphenol to the marine benthic crustacean, Leptocheirus plumulosus was performed under static conditions (Zulkosky et al. 2002). Crustaceans were exposed to control and 4-nonylphenol at average measured concentrations of 2.1, 4.5, 10.5, 27.2 and 61.5 mg/kg dw. A significant negative correlation (p < 0.034) was observed between 4-nonylphenol sediment concentration and the number of young produced per female, but it explained only 12% of the variance. Reproductive output in animals exposed to 61.5 mg/g NP was reduced by 40% of control values, but this difference was not statistically significant (p = 0.299). Thus, the 28d-NOEC value is determined to be >= 61.5 mg /gg dw based on reproduction and mortality. A second study investigated the 28-day long-term toxicity of 4-nonylphenol to Chironomus riparius under semi-static conditions (Bettinetti and Provini 2002). Chironomids were exposed to nonylphenol at nominal concentrations of 270 to 1100 mg/kg sediment dw. The sublethal effects assessed included emergence and egg production. The most sensitive endpoint was emergence. The lowest 28-day EC10 value is determined to be 203 mg/kg dw. The third study investigated the 28-day long-term toxicity of nonylphenol to Tubifex tubifex under semi-static conditions (Bettinetti and Provini 2002). Tubifex were exposed to 4-nonylphenol at nominal concentrations of 90 - 650 mg/kg sediment dw. The sublethal effects assessed included production of cocoons and young worms per adult. The most sensitive end point was number of young worms per adult. The lowest 28-day EC10 value is determined to be 335 mg/kg dw.