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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

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

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

19.6 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 16.8-23.4

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

13.3 µg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 12.3-14.8

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.07 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mobility

Remarks on result:

other: 95% CL 0.06-0.11 mg/l

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 acute aquatic toxicity to invertebrates. Based on the information available for the read across substances, the substance is expected to be acutely toxic to invertebrates .

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study is comparable to a guideline study. Study does not indicate it was performed according to GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.1020 (Gammarid Acute Toxicity Test)

Deviations:

yes

Remarks:

alternate test species was used

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

A stability test sample was collected from each treatment and control immediately after preparation and at 24 h. During toxicity test, all treatments were sampled at test initiations and at 96 h.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: OP stock solutions were prepared by adding 1mg/ml stock solution to acetone to prepare a 1000 µg/L working solution. Distilled water was heated to 80 °C and stirred before addition of acetone.
- Controls: dilution water and solvent controls
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone

Test organisms (species):

Gammarus pulex

Details on test organisms:

TEST ORGANISM
- Common name: freshwater shrimp
- Source: lab culture. Initial stock of organisms were collected from Watlington Brook in 1997
- Age at study initiation (mean and range, SD): 1st and 2nd instar
- Feeding during test: no

ACCLIMATION
- Acclimation period: in house cultures
- Acclimation conditions (same as test or not): same
- Type and amount of food: dead alder leaves
- Feeding frequency: as required
- Health during acclimation (any mortality observed): no mortality observed during holding

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

preliminary range-finding test performed

Post exposure observation period:

none

Hardness:

140-170 mg/L as CaCO3

Test temperature:

13.4-15.8 °C

pH:

7.84-8.25 s.u.

Dissolved oxygen:

90-97% sat.

Salinity:

NA

Nominal and measured concentrations:

range-finding nominal concentrations: 0, 0.01, 0.1, 1.0, 10, 100 µg/L
nominal 0(control), 0 (acetone control), 5.6, 10, 18, 32, 56 µg/L
mean measured <5, 8.9, 10.9, 15.5, 27.2, 50.7 µg/L

Details on test conditions:

TEST SYSTEM
- Renewal rate of test solution (frequency/flow rate): every 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: groundwater with hardness around 170 mg/L CaCO3

- Alkalinity: 95-108 mg/L as CaCO3
- Intervals of water quality measurement: temp, pH, DO measured at start and end of test and at renewal for old and new treatments

OTHER TEST CONDITIONS
- Photoperiod: 16L:8D


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): immobility and mortality assessed every 24 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 0(control), 0 (acetone control), 5.6, 10, 18, 32, 56 µg/L
- Range finding study
- Test concentrations:0, 0.01, 0.1, 1.0, 10, 100 µg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

19.6 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 16.8-23.4

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

13.3 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 12.3-14.8

Details on results:

- Mortality of control: 0%

Results with reference substance (positive control):

none

Reported statistics and error estimates:

Probit method used

Other results presented are (9% cof. int.):

48 h LC50 = 74.8 µg/L (49.4 -306)

48 h EC50 = 30.5 µg/L (26.1 -40.0)

Percent Immobility/Mortality of Gammarus pulex During Test

Concentration (µg/L)	24 h	48 h	72 h	96 h
0 (Control)	0	0	0	0
0 (Acetone control)	0	0	0	0
8.9	0	0*/0*	0*/0*	0*/0*
10.9	0	0*/0*	5#/5#	20#/10#
15.5	0	0 +/0+	35 +/25+	75 +/45+
27.2	0	45/20	70/45	100/65
50.7	0	80/25	95/50	100/100

"+" 1 missing, assumed eaten at 48 h

"*" 2 missing, assumed eaten, at 48 h

"#" 1 missing, assumed eaten at 72 h

Validity criteria fulfilled:

yes

Conclusions:

Study authors conclude that the toxicity of 4-octylphenol is similar to 4-nonylphenol. The authors suggest that they study results support that Environmental Quality Standards for 4-octylphenol could be at similar levels as those for 4-nonylphenol.

Executive summary:

The 96–h-acute toxicity of 4-octylphenol to Gammarus pulex was studied under semi-static conditions.Gammarus were exposed to control, solvent control, and test chemical at measured concentration of 0, 0, 8.9, 10.9, 15.5, 27.2, 50.7 µg/L 4 -octylphenol for 96 h.  Mortality and immobilization effects were observed daily and at test termination.  The 96–h LC₅₀was 19.6 µg/L and EC₅₀was 13.3 µg/L. 

 

Based on the results of this study, 4-octylphenol would be classified as toxic to Gammarus pulex.

 

Sims and Whitehouse (1998) is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age:1^stand 2^ndinstar

Test Type: semi-static

 

LC₅₀:  19.6 µg/L                      95% C.I. :  16.8-23.4 µg/L

EC₅₀:  13.3 µg/L                      95% C.I.:  12.3-14.8 µg/L

 

Sims and Whitehouse (1998) was selected as a key study because results from this study showed the test organism Gammarus pulex was most sensitive organism to octylphenol. In addition, this study was comparable to a guideline study and was well documented.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

unknown

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions which do not impair the overall conclusion from the data

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: US EPA. Methods for measuring the acute toxicity of effluents and recieving waters to freshwater and marine organisms, 4th Ed. EPA 600-4-90-027F. Washing ton DC, US EPA 1993.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Ethanol (0.001% v/v)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Double-deionised water

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

TEST ORGANISM
- Age at study initiation: <24 h old
- Method of breeding: parthenogenesis

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

48 h

Test temperature:

25 +/- 1 °C

Details on test conditions:

Tests performed on C. dubia organisms less than 24 h old. Tested in 24 well plates with 10 crustaceans per well and three replicates per test concentration using 5 concentrations. plates were incubated in darkness for 48 h at 25 +/-1 °C

Reference substance (positive control):

yes

Remarks:

pentahydrate copper sulphate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.07 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mobility

Remarks on result:

other: 95% CL 0.06-0.11 mg/l

Validity criteria fulfilled:

yes

Executive summary:

Isidori et al (2006). Seconda Universita di Napoli ; Klimisch 2d. 

The 48–h-acute toxicity of 4-octylphenol and 4-tert-octylphenol to Ceriodaphnia dubia was studied under static conditions. Ceriodaphnia dubiawere exposed to control, solvent control, and test chemical at nominal test concentration of 4-octylphenol and 4-tert-octylphenol for 48 h.  Immobilization effects were observed daily and at test termination.  The 48 – h EC₅₀was 0.07 mg/L 4-octylphenol and 0.28 mg/L for 4-tert-octylphenol . 

Based on the results of this study, 4-octylphenol would be classified as toxic to Gammarus pulex.

 

Isidori et al (2006) is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age:< 24 h

Test Type: static

 

4-octylphenol EC₅₀: 0.07 mg/L                      95% C.I. :  0.06-0.11 mg/L

4-tert-octylphenol EC₅₀:  0.28 mg/L              95% C.I.:  0.25-0.45 mg/L

 

Isidori et al (2006) was selected as a supporting study because results from this study showed the test organism Ceriodaphnia dubia was one of the more sensitive organisms to octylphenol. In addition, ISO and USEPA (with restrictions) test protocols were followed and study was well documented.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

unknown

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions which do not impair the overall conclusion from the data

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: US EPA. Methods for measuring the acute toxicity of effluents and recieving waters to freshwater and marine organisms, 4th Ed. EPA 6

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Ethanol (0.001% v/v)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Double-deionised water

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

TEST ORGANISM
- Age at study initiation: <24hrs old
- Method of breeding: parthenogenesis

Test type:

static

Water media type:

not specified

Limit test:

no

Test temperature:

25 degrees celcius +/- 1 degree

Details on test conditions:

Tests performed on C. dubia organisms less than 24hrs old. Tested in 24 well plates with 10 crustaceans per well and three replicates per test concentration using 5 concentrations. plates were incubated in darkness for 48hrs at 25 degrees celcisus +/- 1 degree.

Reference substance (positive control):

yes

Remarks:

pentahydrate copper sulphate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.28 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mobility

Remarks on result:

other: 95% CL 0.25 - 0.45 mg/l

Validity criteria fulfilled:

yes

Executive summary:

Isidori et al (2006). Seconda Universita di Napoli ; Klimisch 2d. 

The 48–hr-acute toxicity of 4-octylphenol and 4-tert-octylphenol to Ceriodaphnia dubia was studied under static conditions. Ceriodaphnia dubiawere exposed to control, solvent control, and test chemical at nominal test concentration of 4-octylphenol and 4-tert-octylphenol for 48 hr.  Immobilization effects were observed daily and at test termination.  The 48 – hour EC₅₀was 0.07 mg/L 4-octylphenol and 0.28 mg/L for 4-tert-octylphenol . 

Based on the results of this study, 4-octylphenol would be classified as toxic to Gammarus pulex.

 

Isidori et al (2006) is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age:< 24hr

Test Type: static

 

4-octylphenol EC₅₀: 0.07 mg/L                      95% C.I. :  0.06-0.11 mg/L

4-tert-octylphenol EC₅₀:  0.28 mg/L              95% C.I.:  0.25-0.45 mg/L

 

Isidori et al (2006) was selected as a supporting study because results from this study showed the test organism Ceriodaphnia dubia was one of the more sensitive organisms to octylphenol. In addition, ISO and USEPA (with restrictions) test protocols were followed and study was well documented.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Klimisch 2e. Meets generally accepted scientific standards, well documented and acceptable for assessment. 96 hr test was not renewed.

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1930 (Mysid Acute Toxicity Test)

Deviations:

yes

Remarks:

96 hr test was not renewed

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

yes

Test organisms (species):

Americamysis bahia (previous name: Mysidopsis bahia)

Details on test organisms:

TEST ORGANISM
- Source: laboratory cultures
- Age at study initiation: up to 24 h
- Feeding during test: Artemia of 10, 60 or 110 per mysid per day

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

25 +/- 1 °C

pH:

7.8 -8.3

Dissolved oxygen:

5.9 -7.0 mg/L

Salinity:

- Dilution water salinity: 20%

Nominal and measured concentrations:

- Nominal exposure concentrations: 26, 43, 72, 120 and 200 µg/L

Details on test conditions:

TEST CONDITIONS
- Photoperiod: 14 h light:10 h dark
- Aeration: none

TEST SYSTEM
- Test vessel: 2 litre glass culture dishes
- Type: closed - No. of organisms per vessel: 10 mysids
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 1 (seawater control)
- No. of vessels per vehicle control (replicates): 1 (solvent control)

EFFECT PARAMETER MEASURES
- Mortality observed daily

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.048 - < 0.113 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% CL 0.0361-0.1437

Details on results:

- Mortality of control: up to 15 % for solvent control, no mortality for saltwater control

Reported statistics and error estimates:

- Effect concentration: LC50 calculated using trimmed Spearman-Karber statistical method

Validity criteria fulfilled:

yes

Conclusions:

LC50 values for 96 h exposure ranged from 0.0479 to 0.1131 mg/L.
LC50 values for four compounds (carbophenothion, cypermethrin, malathion and 4-(tert-octyl)phenol) were found to be significantly lower when mysids were fed 10 artemia/myside/day compared to either 60 or 110 a/m/d.

Executive summary:

Cripe, et al, 1989. Gulf Breeze Environmental Research Laboratory (ENVID #4649); Klimisch 2. Mysidopsis bahia were exposed to nominal concentrations of 4-tert-Octylphenol and three different concentrations of Artemia. TSCA guidelines were followed, however, the 96 -h test was not renewed. Control mortality up to 15% was reported in one of the tests. LC₅₀ values for 96 h exposure ranged from 0.0479 to 0.1131 mg/L. These results are an order of magnitude lower than reported LC₅₀values for D. magna at 24 h in the Key Study, and are consistent with typical bioassay results for longer duration exposures. The test results of Cripe et al (1989) imply due to the duration of exposure to attain 50% mortality (96 h versus 24 h in the Key Study) that M. bahia in no more sensitive to acute exposure to octylphenol than C. dubia.

Description of key information

L(E)C50 value for immobility was 0.13 mg octylphenol/L for Gammarus pulex (Sims and Whitehouse 1998)
 Cripe et al.(1989) reported 96 hr LC50 of 0.47 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

LC50

Effect concentration:

0.013 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

LC50

Effect concentration:

0.048 mg/L

Additional information

 

Reliable toxicity data for aquatic invertebrate exposure to octylphenol from 48 to 96 hours included three studies with data for two freshwater and one marine species with immobility or survival test endpoints expressed as L(E)C₅₀concentration. The range of L(E)C₅₀values for immobility was 0.13 mg octylphenol/L for Gammarus pulex (Sims and Whitehouse 1998) to 0.28 mg/L for Ceriodaphniadubia (Isidori et al., 2006). Sims and Whitehouse (1998) distinguished between immobility (EC₅₀) and survival (LC₅₀) and reported a survival endpoint LC₅₀of 0.0196 mg/L for Ceriodaphia dubia.  Cripe et al.(1989) reported LC₅₀range of 0.048 – 0.113 mg/L for survival of the marine species Mysidopsis bahia at 96 hr exposure to octylphenol. 

 

The Sims and Whitehouse (1998) study was selected as the key study because the study was well documented and provided endpoints that distinguished between immobility and survival. Endpoint L(E)C₅₀concentrations reported by the supporting studies of Isidori et al., (2006) and Cripe et al.(1989) were similar to findings of the key study.