4-(1,1,3,3-tetramethylbutyl)phenol

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published study which meets generally accepted scientific standards, well documented and acceptable for assessment.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Deviations:

yes

Remarks:

During soil preparation, the dried contaminated soils were stored in a deep freezer (-20 °C) before use

GLP compliance:

not specified

Application method:

soil

Specific details on test material used for the study:

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

Analytical monitoring:

no

Details on sampling:

Analytical measurements of the same soils were performed under a separate study with Dendrobaena octaedra, which showed that concentrations of nonylphenol in the soil was relatively unchanged after 1.5 years in a freezer (-20 °C), Widarto et al (2004).

The full reference is Widarto T.H, Forbes M, V.E (2004) The influence of nonylphenol on the life history of earthworm Denrobaena octaedra Savigny: linking effects from individual to the population level. Ecotox. Environ. Saf. 58 (2), 147-159.

Vehicle:

yes

Details on preparation and application of test substrate:

- Vehicle: Acetone
- Preparation: The stock solution was prepared corresponding to the highest test concentration (40 mg/kg dw). To contaminate the soil, 225 ml solution was added and mixed into 1.5 kg of the soil. The solvent was evaporated for 24 hours under a fume hood. The dried soils were then put in plastic bags and frozen before use
- Controls: A negative control and solvent control (pure acetone) were used

Test organisms (species):

Folsomia candida

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

- Common Name: Springtail
- Source of test material: A laboratory culture was established at the National Environmental Research Institute (NERI)
- Storage condition before analysis: Maintained as stock cultures in Petri dishes filled with a substrate of moistened plaster of Paris and charcoal
- Feeding: New substrate with dried yeast was prepared every 2-4 weeks and added ad libitum to the cultures
- Age at study initiation: 0-1 day old juveniles were used
- Temperature: Kept at a constant temperature of 20 deg C under a 12 h/12 h light/dark regime

Study type:

laboratory study

Limit test:

yes

Total exposure duration:

64 d

Test temperature:

20 °C

pH (if soil or dung study):

6.2

Humidity:

No Data

Photoperiod and lighting:

- Photoperiod: 12 h/12 h light/dark regime

Details on test conditions:

TEST SYSTEM
- Test vessel: Nunclon multi-well dishes with 24 circular wells (1.5 mm diameter)
- Test Volume: Each well filled with 2.5 g soil containing 15% deionised water
- Food: 2-3 granules of dried bakers yeast added to each well
- Replicates: 12 replicates per treatment. For reproductive endpoints, 6 replicates were used

SOURCE AND PROPERTIES OF SUBSTRATE
- Geographic location: Askov Experimental Station, Denmark.
- Soil texture (if natural soil): Light-textured sandy loam agricultural soil. According to Sverdrup et al (2002) this same soil, although sieved with 2 mm mesh consisted of the following components:
% Sand: 62%
% Silt: 22.3%
% Clay: 13%
% humus: 2.8%
% organic carbon: 1.6%
CEC: 8.14 meq/100 g soil
- Collection procedures: Soil was dried and defaunated at 80 °C then sieved through a 1 mm mesh.

TEST MEDIUM PARAMETERS
- Measurements: Digital image processing equipment (DIP) was used to record body length. Measured body length and monitored survival, molting, egg production and egg development
-No. of measurements: Checked every day until end of experiment to determine molting. Newly hatched neonates were quantified by counting the number of empty egg shells

Nominal and measured concentrations:

- Nominal sublethal concentrations: 0, 8, 16, 24, 32 and 40 mg/kg
- Limit test: Nominal sublethal concentrations were used after a range finding test found that only 42% of the juveniles survived 45 mg/kg

Reference substance (positive control):

no

Duration:

64 d

Dose descriptor:

NOEC

Effect conc.:

32 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Details on results:

No data regarding control

Results with reference substance (positive control):

No Data

Reported statistics and error estimates:

Repeated measures analysis of variance (ANOVA) was used to test for treatment effects on body weight and egg production. Tukey's pairwise comparisons were performed when ANOVA detected significant treatment effects. All statistical analyses were performed with SYSTAT Version 10.

Validity criteria fulfilled:

not specified

Conclusions:

At sublethal concentrations (up to 32 mg/kg dw soil), traits such as growth, time to first moulting and fecundity were stimulated by NP exposure, whereas no effect of NP were observed on time between moults, time to first reproduction, time between broods, number of broods, egg viability or egg development time. In conclusion, the presence of nonylphenol in soil stimulated body growth rate and fecundity of the parthogenetic springtail (F. candida) but did not affect population growth rate.

Executive summary:

In a 64-day chronic toxicity study, collembola (Folsomia candida) were exposed at control and nonylphenol at a range of concentrations between 0, 8, 16, 24 and 32 mg/kg. The NOEC based on survival was 32 mg nonylphenol/kg, using a natural sandy loam soil. Based on the results of this study, nonylphenol would be considered to have adverse chronic effects to Folsomia candida.

This study is classified as acceptable and was undertaken according to good scientific practice.

Reference 2

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

In accordance with Regulation (EC) 1907/2006 Annex XI (1.5) and the relevant ECHA guidance documents, the substances detailed in the table below are grouped for the purposes of read across to reduce the need for unnecessary repeat testing on the basis that the substances are similar on the basis of a common functional groups.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

63.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: (47.3, 84.5)

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

24 mg/kg soil dw

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

27 mg/kg soil dw

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

23 ng/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

64 d

Dose descriptor:

NOEC

Effect conc.:

32 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survivial

Conclusions:

The read across for 4-tert-octylphenol (CAS: 140-66-9); is based upon the analogous substances to which basic form, degree of substitution of functional groups is not considered to effect the proposed read across for the endpoint of Toxicity to terrestrial arthropods. Based on the information available for the read across substances, the substance is expected to be toxic to terrestrial arthropods.

Reference 3

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment.

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Deviations:

yes

Remarks:

The duration is 21 days unlike the standard 28 day exposure.

Principles of method if other than guideline:

Although the author does not explicitly reference an OECD or ISO Guideline, the author does state that the aim of the study is to evaluate the lethal and sublethal toxicity of NP to the springtail as performed in standard tests used in risk assessment. The test is described in similar terms to a standard Collembolan test, although the duration is one week shorter than the standard duration of 28 days.

GLP compliance:

not specified

Application method:

soil

Specific details on test material used for the study:

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

Analytical monitoring:

no

Details on sampling:

Start of test: 10 adult female and 10 adult male (aged 19-23 days) were added to each replicate microcosm on Day 0 and exposed for 21 days
End of test: All surviving animals were extracted in a high gradient Tullgren funnel and collected in a cooled (4 °C) collecting dish prior to analysis. Adults and juveniles were counted by an automated process using a Digital Image Processing (DIP) system. The DIP system allowed the differentiation between females, males and juveniles by the use of ordination techniques using Principal Component Analysis (PCA).

Vehicle:

yes

Details on preparation and application of test substrate:

- Vehicle: Acetone
- Preparation: Nonylphenol was added from a stock solution dissolved in pure acetone. Prior to the test the acetone was evaporated from the soil. To contaminate the soil, nonylphenol was mixed homogeneously into the soil 24 h prior to the start of the test.
- Control: Negative control and solvent (acetone) controls were included in the study design

Test organisms (species):

Folsomia sp.

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

Species: Folsomia fimetaria
Common Name: Springtail
Source: Laboratory culture established from field collected animals
Storage condition before analysis: Kept in petri dishes on a substrate of moistened plaster of Paris and charcoal
Feeding: Before analysis animals were fed dried yeast ad libitum and every 2-4 weeks the adult animals were transferred to new substrate with fresh food
Age at study initiation: 19 to 23 day old

Study type:

laboratory study

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

No Data

Test temperature:

20 °C

pH (if soil or dung study):

6.5

Humidity:

No Data

Photoperiod and lighting:

12/12 h light/dark regime

Details on test conditions:

TEST SYSTEM
- Test vessel: Microcosms
- Test Volume: Each vessel contained 30 g of moist soil (27 g dry soil and 3 ml demineralised water)
- Exposure: The nonylphenol stem solutions were added to the soil 24 h prior to test and all the acetone was allowed to evaporate within the next 24 h. The animals were exposed to 3 exposure regimes, each with 6 exposure concentrations and four replicates per concentration
- Food: The animals were fed dried bakers yeast (15 mg dry weight) on days 0, 7 and 14
- Number of animals per vessel at the start of the test: 10 adult males and 10 adult females were added to each replicate microcosm on day 0

SOIL MEDIUM:
Soil used was a sandy loam with the following properties:
% Sand: 74.6%
% Silt: 11.8%
% Clay: 10.6%
% humus: 3.0%

TEST MEDIUM PARAMETERS
- Measurements: Adults and juveniles were counted by automated process and measured for body area, length, width, slimness and optical gray intensity by a digital image processing system (DIP)

Nominal and measured concentrations:

Nominal concentrations of 0, 20, 40, 60, 80 and 100 mg/kg (dry weight)

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

23 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

No data regarding control

Results with reference substance (positive control):

No Data

Reported statistics and error estimates:

The data was checked for normality using a X2 test, and for homogeneity of variance by Barlett's test. The no-observable-effect concentration (NOEC) were estimated by Tukey's studentized range (HSD) test (SAS Institute Inc (1989) SAT/STAT User Guide, Version 6). Effect concentrations, EC10 and EC50, and bootstrapping intervals were estimated by fitting a logistic model to the data (Norberg-King, T.J (1993) A linear interpolation method for sublethal toxicity: the inhibition concentration approach (Version 2) and Dunnet program (Version 1.5). NETAC Technical Report 03-93).

In addition to the EC₁₀ for reproduction effects, the authors report the following effect concentrations:

- EC₁₀ based on growth in juveniles of 23 mg/kg;

- EC_{10 based on growth in adults of 32 mg/kg; and}

- EC_{10 based on survival in adults of 55 mg/kg.}

Validity criteria fulfilled:

not specified

Conclusions:

The study showed that nonylphenol causes mortality and has reproductive effects in the springtail Folsomia fimetaria at nonylphenol concentrations above approximately 5 mg/kg dry soil. The toxicity is independent of whether NP is added directly to the soil or via sludge mixed homogenously into the soil.

Executive summary:

In a 21-day chronic toxicity study, collembola (Folsomia fimetaria) were exposed at control and nonylphenol at a range of concentrations between 0, 20, 40, 60, 80, and 100 mg/kg dry weight. The EC₁₀ based on reproduction was 23 mg nonylphenol/kg, using a natural sandy loam soil. Based on the results of this study, nonylphenol would be considered to have adverse chronic effects to Folsomia fimetaria.

This study is classified as acceptable and was undertaken according to good scientific practice.

Reference 4

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No Data

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The reference is the European Union Risk Assessment Report for nonylphenol (2002) which is classified as secondary literature. However, it is a highly trusted source which has undergone significant expert review and ratification by the European Commission. As such, the data within the EURAR (2002) is trusted and presented within this dossier.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline available

Principles of method if other than guideline:

No Data

GLP compliance:

not specified

Application method:

other: Artifical Soil (LUFA)

Specific details on test material used for the study:

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

Analytical monitoring:

not specified

Details on sampling:

No Data

Vehicle:

not specified

Details on preparation and application of test substrate:

No Data

Test organisms (species):

Folsomia sp.

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

Test Species: Folsomia fimetaria

Study type:

laboratory study

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

No Data

Test temperature:

No Data

pH (if soil or dung study):

No Data

Humidity:

No Data

Photoperiod and lighting:

No Data

Details on test conditions:

- Soil Type: LUFA Soil

Nominal and measured concentrations:

No Data

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

24 mg/kg soil ww

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

No Data

Results with reference substance (positive control):

No Data

Reported statistics and error estimates:

No Data

Validity criteria fulfilled:

not specified

Conclusions:

The original study was not available for independent review so the authors' conclusions cannot be presented here.

Executive summary:

In a 21-day chronic toxicity study, collambolans (Folsomia fimetaria) were exposed to nonylphenol with an EC₁₀ based on reproduction of 24 mg nonylphenol/kg, using an artificial soil test medium. Based on the results of this study, nonylphenol is considered to have adverse effects on Folsomia fimetaria.

This study was classified as acceptable by the European Commission in its 2002 Risk Assessment Report on nonylphenol, although ENVIRON was unable to review the primary literature and evaluate the study's reliability.

Reference 5

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No Data

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The reference is the European Union Risk Assessment Report for nonylphenol (2002) which is classified as secondary literature. However, it is a highly trusted source which has undergone significant expert review and ratification by the European Commission. As such, the data within the EURAR (2002) is trusted and presented within this dossier.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline available

Principles of method if other than guideline:

No Data

GLP compliance:

not specified

Application method:

soil

Specific details on test material used for the study:

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

Analytical monitoring:

not specified

Details on sampling:

No Data

Vehicle:

not specified

Details on preparation and application of test substrate:

No Data

Test organisms (species):

Folsomia sp.

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

Test Species: Folsomia fimetaria

Study type:

laboratory study

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

No Data

Test temperature:

No Data

pH (if soil or dung study):

No Data

Humidity:

No Data

Photoperiod and lighting:

No Data

Details on test conditions:

- Soil type: sandy soil

Nominal and measured concentrations:

No Data

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

27 mg/kg soil ww

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

No Data

Results with reference substance (positive control):

No Data

Reported statistics and error estimates:

No Data

Validity criteria fulfilled:

not specified

Conclusions:

The original study was not available for independent review so the authors' conclusions cannot be presented here.

Executive summary:

In a 21-day chronic toxicity study, collembolans (Folsomia fimetaria) were exposed to nonylphenol with an EC₁₀based on reproduction of 27 mg nonylphenol/kg, using a natural soil medium. Based on the results of this study, nonylphenol is considered to have adverse effects on Folsomia fimetaria.

This study was classified as acceptable by the European Commission in its 2002 Risk Assessment Report on nonylphenol, although ENVIRON has not been able to review the primary literature.

Reference 6

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Spring 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Published paper which meets international standard methods including OECD and ISO Guidelines.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Deviations:

yes

Remarks:

Test vessel was plastic, not glass, but this is not thought to influence the test results.

GLP compliance:

no

Application method:

soil

Specific details on test material used for the study:

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

Analytical monitoring:

no

Details on sampling:

- Concentrations: The test concentrations were selected following a preliminary assay consisting of 0, 1, 10, 100, 1000 and 10000 mg of nonylphenol per kg of soil. The range of concentrations showing an inhibition between 10% and 90% were selected for the study.

Vehicle:

yes

Details on preparation and application of test substrate:

- Vehicle: Nonylphenol was applied to soils dissolved in acetone (95%, Panreac, Barcelona, Spain).
- Application: To prepare the concentrations of test substance, the amount of soil to be used for each concentration was moistened with a fixed volume of acetone solution containing the appropriate quantity of nonylphenol. Acetone was then left to evaporate for 24 hours in a fume hood.
- Controls: Two control soils were prepared; one negative control and one solvent control to which the same volume of acetone was added as was used in the test substance concentrations.

Test organisms (species):

Folsomia candida

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

TEST ORGANISM
- Common name: Springtail
- Age at test initiation: 10-12 days old

ACCLIMATION
- Feeding: Fed 3 mg of yeast at the start of the bioassay and after day 14.

Study type:

laboratory study

Limit test:

yes

Total exposure duration:

28 d

Test temperature:

20 °C +/- 2 °C

pH (if soil or dung study):

6 +/- 0.5 (as per OECD Artificial Soil) adjusted using calcium carbonate

Humidity:

No data

Photoperiod and lighting:

Not given but should be in accordance with the ISO Protocol (light:dark cycle between 12 h:12 h and 16 h:8 h).

Details on test conditions:

TEST SYSTEM
- OECD artificial soil: Prepared according to the OECD protocol for artificial soil (1984) by mixing Sphagnum peat (10%), kaoline (20%) and quartz sand.
- Testing facility: Universitat Autonoma de Barcelona
- Test container (type, material, size): Each replicate consisted of a 100-ml plastic cup.
- Amount of soil: Each vessel was filled with 30 g soil (dry weight)
- No. of replicates per treatment group: 5 replicates per concentration were prepared
- Number of organisms: Ten individuals aged 10-12 days old were introduced into each cup.
- Feeding: Animals were fed with 3 mg of yeast at the start and after day 14.

SOURCE AND PROPERTIES OF SUBSTRATE
- Geographic location: The results presented here relate to the OECD Artificial Soil, however two natural soils were also tested. These correspond to a loamy agricultural soil (PRA) within the Universitat Autonoma de Barcelona campus (Cerdanyola del Valles, NE Spain) and the other was a loam sand soil (UAB) from the dry grassland in Serra de Prades (Tarragona, NE Spain).
- Pesticide use history at the collection site: Not relevant to the OECD Artificial Soil, however, pesticide use had ceased five years previously in the agricultural soil (UAB).
- Collection procedures: Natural soils were defaunated by alternating two consecutive freeze-thaw cycles (-20 °C for 4 days, then +20 °C for 4 days).
- Sampling depth (cm): Not relevant to the OECD soil, but natural soils were collected from the upper layer (20 cm).
- Soil texture (if natural soil): PRA soil
- % sand: 80.3
- % silt: 16.5
- % clay: 3.2

- Soil texture (if natural soil): UAB soil
- % sand: 36.4
- % silt: 44.9
- % clay: 18.7

- Composition (if artificial substrate): OECD Artificial Soil
- Organic carbon (%): 3.45
- Maximum water holding capacity (in % dry weight): 44.8% adjusted to 60% WHC
- CEC: 8.94

END OF TEST
- Test vessels were flooded with water into a 500-ml beaker followed by the addition of a dark dye to allow the taking of a photograph of the individuals floating on the water's surface.
- Adults and juveniles were differentiated by size.
- All the individuals counted were assumed to be alive given the quick degradation time of individuals once dead.

Nominal and measured concentrations:

Nominal concentrations: The test concentrations were selected following a preliminary assay consisting of 0, 1, 10, 100, 1000 and 10000 mg of nonylphenol per kg of soil. The range of concentrations showing an inhibition between 10% and 90% were selected for the study.

Reference substance (positive control):

no

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

63.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: (47.3, 84.5)

Details on results:

No differences in the outcomes between controls with and without the addition of acetone were found in any of the assays. Validity criteria were met for all species.

- Survival was over 80%
- Reproduction was over 100 juveniles with a coefficient of variation below 30%.

Mean values (+/- standard deviation) are provided for the controls in the different test soils below:
- Survival in adults: OECD 9.1 (±0.9); PRA 9.4 (±0.8); UAB 9.4 (±0.9)
- Reproduction in juveniles: OECD 1323.6 (±189.5); PRA 957.5 (±315.5); UAB 900.2 (±110.2)

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

EC10 and EC50 data were analysed using Statistica 6.0 (StatSoft Inc., Tulsa, OK, USA)

Reproduction was a more sensitive endpoint than survival in the collembolan study. By way of comparison using the OECD artificial soil, the EC₁₀ for reproduction was 63.2 mg/kg compared with the EC₁₀ and EC₅₀ for survival which were 102 and 138.7 mg/kg respectively. When the results for the three soils were compared, collembola (reproduction) in OECD Artificial Soil (EC₁₀ of 63.2 mg/kg) was slightly less sensitive than collembola in the other soils; reproduction in the PVA soil (EC₁₀ of 45 mg/kg) and UAB soil (

EC₁₀ of 54.8 mg/kg). The results for the OECD Artificial Soil have been selected for this hazard assessment as the standard soil data are directly comparable with other studies where artificial soils were used (for example, Johnson et al, 2005).

Toxicity values of 4 -nonylphenol for several terrestrial organisms in the three different soil types:

Species	Endpoint	Soil	EC10	EC50
B. rapa	Freshweight	OECD	574.8 (279.9, 1,180.4)	1,449.1 (785.0, 2,674.7)
	Germination		695.9 (286.3, 1,691.6)	8,159.2 (5,904.0, 11,276.0)
L. perenne	Freshweight	OECD	738.9 (49.6, 11,011.2)	4,011.6 (862.2, 18,664.5)
	Germination		1,385.8 (696.5, 2,757.3)	7,500.7 (6,031.2, 9,328.3)
E. andreii	Survival	OECD	343.9 (160.6, 736.4)	625.5 (427.9, 914.1)
		PRA	182.4 (157.6, 211.2)	290.7 (272.0, 310.7)
		UAB	498.2 (439.2, 565.2)	622.0 (592.3, 653.2)
	Reproduction	OECD	55.8 (13.7, 227.7)	82.0 (47.6, 141.1)
		PRA	43.1 (26.9, 69.0)	69.6 (57.7, 83.9)
		UAB	63.6 (46.5, 87.1)	124.3 (110.5, 139.9)
	Biomass	OECD	88.3 (50.0, 155.8)	309.1 (240.4, 397.3)
		PRA	121.2 (93.6, 156.9)	240.2 (218.0, 264.8)
		UAB	289.4 (219.1, 382.4)	523.2 (474.5, 576.9)
E. crypticus	Survival	OECD	663.5 (444.9, 989.5)	906.7 (786.5, 1,045.3)
		PRA	214.5 (171.3, 268.6)	316.2 (284.9, 350.9)
		UAB	227.0 (89.5, 575.3)	615.2 (431.9, 876.3)
	Reproduction	OECD	24.0 (5.2, 110.7)	225.8 (134.8, 378.4)
		PRA	455.8 (311.2, 667.5)	641.7 (554.2, 742.9)
		UAB	197.2 (97.9, 397.3)	212.8 (194.6, 232.8)
F. candida	Survival	OECD	102.0 (69.7, 149.3)	138.7 (129.4, 148.7)
		PRA	52.3 (47.0, 58.1)	69.8 (65.8, 74.1)
		UAB	89.1 (70.0, 113.5)	116.3 (104.2, 129.8)
	Reproduction	OECD	63.2 (47.3, 84.5)	92.8 (83.8, 102.8)
		PRA	45.0 (27.5, 73.7)	64.4 (54.6, 75.9)
		UAB	54.8 (23.9, 125.7)	88.0 (79.9, 96.9)

Validity criteria fulfilled:

yes

Conclusions:

The authors considered nonylphenol to be more toxic than the nonylphenol ethoxylate mixture and considered the results to be in agreement with existing published literature. Nonylphenol presented low phytotoxicity but moderate toxicity for invertebrates, reproduction being clearly the most sensitive endpoint. Nonylphenol generally affected the invertebrates' reproduction at lower concentrations than those affecting growth or survival. Earthworms and collembolans were more sensitive taxa compared to enchytraeids.

Executive summary:

In a 28 -day chronic toxicity study, collembola (Folsomia candida) were exposed at control, solvent control, and nonylphenol at a range of concentrations showing inhibition between 10% and 90% from an initial range-finding test. The EC₁₀ based on reproduction was 63.2 mg nonylphenol/kg, using an artificial soil test medium. Results for two natural soils were also reported. Based on the results of this study, nonylphenol would be considered to have adverse chronic and acute effects to Folsomia candida.

This study is classified as acceptable and is similar in methodology to the requirements of the ISO Guideline 11267 (ISO, 1999).

Description of key information

No reliable short-term data were available specifically relating to arthropods. However, the key study by Scott-Fordsmand et al., (2004) reported an EC10 based on Folsomia fimetaria reproduction of 23 mg nonylphenol/kg.  This study is reliable with restriction, using the Folsomia genus, an oven-dried soil and is equivalent to an international ISO protocol. Importantly, this is the lowest EC10 in the reliable dataset.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:

23 mg/kg soil dw

Additional information

There were five reliable studies relating to the long-term exposure of arthropods to nonylphenol; no reliable short-term data were available. Two studies met the strict adequacy requirements of the IUCLID Robust Study Summary; these were the Scott-Fordsmandet al.,(2004) and the Domeneet al.,(2009) study. The long-term data for Collembola species ranged from 23 to 63.2 mg nonylphenol/kg with test durations ranging from 21 to 64 days.

Three studies provided comparable data forFolsomia fimetariaexposure to nonylphenol for 21 days with EC10 values of 23, 24 and 27 mg nonylphenol/kg, relating to the studies by Scott-Fordsmand and Krogh (2004), Krogh (1996) and Holm (undated, but reported in the nonylphenol EU Risk Assessment Report, 2002). ENVIRON has not been able to review the Krogh (1996) and Holm studies directly but the data from these studies is taken directly from the EURAR (2002) and offered as supporting information here. Thestudy by Widartoet al.,(2007) presented a 64-day NOEC value based on survival onFolsomia candidaof 32 mg nonylphenol/kg. These four studies correspond closely to each other and provide strong evidence that no-effect or EC₁₀levels for Collembola are between 23 and 32 mg/kg.

However, these three studies whilst considered acceptable for REACH purposes were classified as ‘reliable with restrictions’ (Klimisch 2) as the studies were all shorter than the standard duration (28 days) and lacked crucial information, such as the purity of the chemical. The studies considered to provide adequate information for a Robust Study Summary, whilst being reliable, were those by Scott-Fordsmandet al., (2004) and Domeneet al,. 2009. In the Scott-Fordsmand study reportedFolsomia fimetarialong-term toxicity EC10 of 23 mg/kg. The Domeneet al.,(2009) study reported,Folsomia candida, the preferred test species was exposed to nonylphenol in artificial soil for the recommended duration of 28 days. The resulting EC₁₀was 63.2 mg nonylphenol/kg. However, the Scott-Fordsmand et al (2004) study is recommended as the key study as this represents the most sensitive toxicity data and is supported by the evidence of similar or slightly higher toxicity-based NOEC/EC10 values. The study meets the reliability and adequacy requirements of REACH.