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

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)

Deviations:

no

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil (if used):The test substance was applied to soil dissolved in acetone. To prepare the concentrations, the amount of soil to be
used for each concentration was moistened with a fixed volume of acetone solution containing the appropriate quantity of the test substance. Prior to the addition of acetone, and for each concentration prepared, a small portion of the untreated soil (20%) was kept aside in order to reinoculate the polluted soil once the acetone had evaporated.
- Controls: Two control soils were prepared, one to which the same volume of acetone was added and another one to which acetone was not added and that served to detect any noxious effect directly linked to the acetone addition.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Evaporation of vehicle before use: Acetone was left to evaporate for 24 h in a fume hood.

Species:

Lolium perenne

Plant group:

Monocotyledonae (monocots)

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Test type:

other: germination and biomass production

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

15 d

Test temperature:

21 °C

pH:

6.2

Moisture:

60% of max water-holding capacity

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): 250 mL polyethylene cup filled with 100 g soil (dw)
- No. of seeds per container: 10
- No. of replicates per treatment group: 5
- No. of replicates per control: 5
- No. of replicates per vehicle control: 5

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- % sand: 45.7
- % silt: 31.8
- % clay: 16.3
- Composition (if artificial substrate): The artificial soil was prepared according to OECD (1984) by mixing Sphagnum peat (10%), kaoline (20%), and quartz sand. Soil pH was adjusted to 6±0.5 with the addition of calcium carbonate.
- Organic carbon (%): 3.45
- CEC: 8.94 meq/100g

GROWTH CONDITIONS
- Photoperiod: 16h light/ 8h dark

EFFECT PARAMETERS MEASURED: Germination and seedling biomass was recorded after 15 days exposure time.

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 1, 10, 100, 1000, 10000 mg/kg
- Results used to determine the conditions for the definitive study: The range of concentrations showing an inhibition between 10% and 90% were selected for the definitive assay.

Nominal and measured concentrations:

Nominal: not specified. A preliminary assay consisted of 0, 1, 10, 100, 1,000, and 10,000 mg/kg. The range of concentrations showing an inhibition between 10% and 90% were selected for the definitive assay.

Reference substance (positive control):

no

Key result

Species:

Brassica rapa

Duration:

15 d

Dose descriptor:

EC50

Effect conc.:

1 449.1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: EC50 (germination) = 8159.2 mg/kg

Species:

Brassica rapa

Duration:

15 d

Dose descriptor:

EC10

Effect conc.:

574.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: EC10 (germination = 695.9 mg/kg

Species:

Lolium perenne

Duration:

15 d

Dose descriptor:

EC10

Effect conc.:

738.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: EC10 (germination) = 1385.8 mg/kg

Species:

Lolium perenne

Duration:

15 d

Dose descriptor:

EC50

Effect conc.:

4 011.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: EC50 (germination) = 7500.7 mg/kg

Details on results:

The germination rates in OECD soil for B. rapa and L. perenne were over 95%. The fresh weight of the control seedlings was 854 ± 119 and 219 ± 22 mg, respectively, with no signs of nutrient deficiency. No tests were carried out in natural soils because in plants NP generally showed inhibitory effects over 1 g/kg in OECD soil in the preliminary test. This is the concentration above which a pollutant is not considered as toxic according to the test protocol used in this study.

Validity criteria fulfilled:

yes

Conclusions:

Strong inhibition effects on germination and fresh weight (EC50) were only observed at very high concentrations (>1 g/kg), too high levels to consider these chemicals as phytotoxic according to OECD criteria.

Executive summary:

The toxicity of 4-nonylphenol to terrestrial plants was investigated according to OECD guideline 208 using L. perenne and B. rapa as test organisms. Artificial soil according to OECD was used. Germination and biomass production was recorded after an exposure time of 15 days. Fresh weight was found to be a more sensitive endpoint than germination. However, all 15d-EC50 value showed to be > 1g/kg, which is not considered as toxic according to OECD criteria. The lowest 15d-EC10 value is determined to be 574.8 mg/kg dw.

Reference 2

Endpoint:

toxicity to terrestrial plants: 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

Key result

Species:

Brassica rapa

Duration:

15 d

Dose descriptor:

EC50

Effect conc.:

1 449.1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: EC50 (germination) = 8159.2 mg/kg

Description of key information

EC50 (15d) > 1000 mg/kg (nominal, fresh weight) for Brassica rapa (OECD 208, read across)

Additional information

Since no study assessing the toxicity of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0) to terrestrial plants is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to Phenol, 4-nonyl-,branched was conducted, which is a secondary component and structurally similar to the main component of the substance. The only structural difference between the source substance and the target substance is the lack of a ketoxime group at the phenol ring of the molecule.

The read across is justified due to the following reasons:

1) The similarity of structure and functional groups and accordingly similar physico-chemical properties result in similar environmental behavior and fate.

2) Based on a profound ecotoxicological data set available for Phenol, 4-nonyl-,branched it can be concluded that Phenol, 4-nonyl-,branched exhibit a higher aquatic toxicity compared to Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (see table below). Therefore, using data from Phenol, 4-nonyl-,branched to assess the intrinsic hazard of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched is considered to be a very conservative approach (worst case scenario).

Substance	Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched	Phenol, 4-nonyl, branched^*
CAS number	244235-47-0	84852-15-3
Structure	see attachment (chapter 6.3)	see attachment (chapter 6.3)
Molecular formula	C17H27NO2	C15H24O
Molecular weight	~ 277 g/mole	~ 220.35 g/mole
PC parameter
Water solubility	> 0.02 < 1 mg/L (EU method A.6)	5.7 mg/L (ASTM E 1148-02)
Partition coefficient	> 5.7(EU method A.8)	5.4 (OECD 117)
Vapour pressure	< 1.5 Pa at 20 °C (OECD 104)	~1 Pa at 20 °C (ASTM-D 2879)
Environmental fate
Biodegradability	1 % in 28 days (BODIS)	non-adapted inoculum: 0 % in 28 days (OECD 301B)   adapted inoculum: 48.2-62 % in 28 days (OECD 301B)
Adsorption [log KOC]	3.9 (OECD 121)	4.35 - 5.69 (EPA OTS 796.2750)
Hydrolysis	not relevant
Ecotoxicology
Short-term toxicity to fish [96h-LC50]	0.46 mg/L (EU method C.1)	0.05 – 0.22 mg/L (different methods)
Long-term toxicity to aquatic invertebrates [NOEC]	-	0.006 mg/L (ASTM E 1241-05)
Short-term toxicity to aquatic invertebrates [48h-EC50]	9.55 mg/L (OECD 202)	0.08 – 0.14 mg/L (different methods)
Long-term toxicity to aquatic invertebrates [21d-NOEC]	2.8 mg/L (OECD 211)	0.024 - 0.116 mg/L (different methods)
Short-term toxicity to algae [72h-EC50]	760 mg/L(OECD 201)	0.33 - 1.3 mg/L (different methods)
Long-term toxicity to algae [72h-NOEC/EC10]	472 mg/L (OECD 201)	0.5 mg/L (Algal growth inhibition test according to UBA 1984)
Toxicity to microorganisms [EC50]	> 1000 mg/L (OECD 209)	950 mg/L (OECD 209)

* Data were taken from Phenol, 4-nonyl-,branched (CAS 84852-15-3) dossier published on the ECHA data base

 

The toxicity of 4-nonylphenol to terrestrial plants was investigated according to OECD guideline 208 using L. perenne and B. rapa as test organisms (Domene et al. 2009). Artificial soil according to OECD was used. Germination and biomass production was recorded after an exposure time of 15 days. Fresh weight was found to be a more sensitive endpoint than germination. However, all 15d-EC50 value showed to be > 1g/kg, which is not considered as toxic according to OECD criteria.

Based on the reasons given above this value is considered to be sufficiently conservative to be used for the hazard assessment of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0).