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

Toxicity to other aquatic organisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to other aquatic vertebrates

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:

50 d

Dose descriptor:

LC10

Effect conc.:

0.68 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mortality

Duration:

50 d

Dose descriptor:

NOEC

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: all parameters measured

Remarks on result:

other: NOEC is inferred

Duration:

9 wk

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

9 wk

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction

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 other aquatic vertebrates. Based on the information available for the read across substances, the substance is expected to be toxic to other aquatic vertebrates.

Reference 2

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

mid June-end of July

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets generally accepted scientific standards, well documented and acceptable for assessment. Study does not state it was performed under GLP and test concentrations were not measured.

Qualifier:

no guideline available

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

none

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Controls: solvent and dilution water control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): ethyl acetate 99.9%
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)):maximum concentration in a test chamber = 50 µg/L

Test organisms (species):

other: Dreissena polymorpha

Details on test organisms:

TEST ORGANISM
- Common name: zebra mussel
- Source: feral organisms collected in 1 m depth by scraping floating buoys in Lough Ree, County Westmeath, Ireland
- Age at study initiation (mean and range, SD): 10-15 mm or 15-30 mm
- Feeding during test: yes
- Food type: Phytoplex commercial bivalve food
- Frequency: after each renewal


ACCLIMATION
- Acclimation period: 7-10 days
- Acclimation conditions (same as test or not): acclimation temperature 10-12 °C, test temperature 12-16 °C, otherwise same as test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

50 d

Post exposure observation period:

none

Hardness:

not measured

Test temperature:

12-16 °C

pH:

not measured

Dissolved oxygen:

not provided, but test chambers were aerated

Salinity:

NA

Nominal and measured concentrations:

nominal: 0.1, 1.0, 5.0, 10.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 15 L glass tanks with tiles for mussel attachment
- Renewal rate of test solution (frequency/flow rate): 3 times a week
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of organisms per vessel: 100
- No. of vessels per vehicle control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap
- Total organic carbon: not provided
- Intervals of water quality measurement: beginning of test and after 96 h
- Dissolved oxygen: adequate throughout test

- Photoperiod: 12L:12D

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): survival observed daily, mortality was assessed by inactivation of mantle-edge muscles, cessation of adductor muscles function and cessation of siphon retraction. Valve gaping was also assessed. Sublethal effects include re-attachment, siphon activity.

Reference substance (positive control):

no

Duration:

50 d

Dose descriptor:

LC10

Effect conc.:

0.68 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mortality

Duration:

50 d

Dose descriptor:

NOEC

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: all parameters measured

Remarks on result:

other: NOEC is inferred

Details on results:

No significant difference found between control and solvent control mortality. Control mortality < 20%
NOEC of 0.1 mg/L is inferred from the following statement from the study: "the lowest concentration of 0.1 mg/L did not have any observable effect on the parameters measured."

Reported statistics and error estimates:

LC10 determined by linear regression

The study notes the following significant sub-lethal effects:

attachment and siphon extension effects seen at 5 and 10 mg/L

filtration effects seen at 1 mg/L

Summary of p-values for Parameters Assessed/Effects for Nonylphenol Exposure to Zebra Mussel

	Mortality	Attachment	Filtration
SC:C	0.2	0.12	0.35
SC:0.1 mg/L	0.53	0.55	0.72
SC:1.0 mg/L	0.15	0.064	0.006*
SC:5 mg/L	0.008*	0.0003*	2.28E-13*
SC:10 mg/L	0.04*	0.0001*	9.89E-10*

SC = solvent control, C=control

*Significant at p<0.05

Study also performed a test to assess endocrine disrupting effects. These are not presented here.

Validity criteria fulfilled:

yes

Conclusions:

Study authors conclude that the threshold level concentration of nonylphenol toxicity to zebra mussels is 0.68 mg/L.

Executive summary:

In a 50 day chronic toxicity study, the zebra mussel, Dreissena polymorpha, was exposed to control, solvent control and nominal concentrations of nonylphenol of 0.1, 1.0, 5.0, 10.0 mg/Lnonylphenol under semi-static conditions.  The 50 -day LC₁₀was 0.68 mg nonylphenol/L which was based on mortality. Sublethal effects measured included filtration and attachment.

 

Results Synopsis

 

Test organism size/age:10 -15 mm

Test Type: semi-Static

 

LC₁₀: 0.68mg nonylphenol/L. 

Endpoint(s) Effected:  Survival

 

Quinn et al. (2006) was considered a supporting study because it provided data for a potentially sensitive aquatic organism, Dreissena polymorpha. There were no other reliable studies for this species.

Reference 3

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

16 May 2000 - 16 July 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets generally accepted scientific standards and is acceptable for assessment. Study is missing information pertaining to test procedures.

Qualifier:

no guideline available

Principles of method if other than guideline:

Snails exposed to octylphenol for 9 weeks in semi-static renewal system. Growth and embryo production were assessed.

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

NA

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Controls: solvent control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): ethanol
- Concentration of vehicle in test medium (stock solution and final test solution): 12.5 ug/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc):not provided

Test organisms (species):

other: Potamopyrgus antipodarum

Details on test organisms:

TEST ORGANISM
- Common name:snail
- Source: lab cultured in Zittau University in Germany
- Age at study initiation (mean and range, SD): adult
- Feeding during test: yes
- Food type: lettuce leaves


ACCLIMATION
- Acclimation period: not needed as cultured in lab

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

9 wk

Post exposure observation period:

none

Hardness:

0.51 mg CaCO3/L

Test temperature:

14 deg C +/- 1 °C

pH:

7.4-7.9 s.u.

Dissolved oxygen:

not provided

Salinity:

NA

Nominal and measured concentrations:

nominal: control, 1, 5, 25, 100 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 1 cubic m tanks or 1L Erlenmeyer flasks
- Renewal rate of test solution (frequency/flow rate): renewed every 4 days
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): not provided
- No. of vessels per control (replicates): not provided

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap

OTHER TEST CONDITIONS
- Photoperiod:16L:8D


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : growth and embryo number assessed at 0, 3, 6, and 9 weeks

Duration:

9 wk

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

9 wk

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction

Details on results:

No effects on survival, little effect on shell height or operculum width except for the 25 µg/L concentration where shell height seemed to be enhanced. After 3 weeks, OP caused a stimulatory effect on the embryo production.

Reported statistics and error estimates:

One-way ANOVA or students t-test used to compare treatments

Validity criteria fulfilled:

not specified

Conclusions:

Study authors conclude that lab-based studies demonstrated that all of the tested chemicals affected embryo production in P. antipodarum. Therefore, compared with the fish species also tested, P. antipodarum is a potentially sensitive test organism for assessing estrogenicity of chemicals with relevance to their activity in vertebrates.

Executive summary:

The 9 -week chronic toxicity of octylphenol to the snail, Potamophyrgus antipodarum, was studied under static renewal conditions. Snails were exposed to control, and nominal test chemical at concentrations of 0.001, 0.005, 0.025, and 0.1 mg octylphenol./L.  The 9 -week NOEC based on survival was 0.1 mg octylphenol./L.  The sublethal effects included were growth, defined by shell height, as well as embryo production.  Production of offspring in the treated groups indicated that octylphenol did not have an effect on the reproduction at concentrations tested resulting in a NOEC of > 0.1 mg/L octylphenol.  The most sensitive end point was not determined.

 

 

Results Synopsis

 

Test Organism Age (e.g. 1^stinstar): adult

Test Type (Flow through Static, Static Renewal): semi-static

 

NOEL:  >0.1 mg/L octylphenol

               Endpoint(s) Effected:  survival, growth and reproduction

 

Jobling et al. (2003) was selected as a supporting study because results from this study showed toxicity results for the sensitive test organism the snail, Potamphorgus antipodarum. No other reliable long-term data was available for the toxicity of octylphenol to this species.

 

Description of key information

Nine week NOEC of 0.1 ug/L octylphenol based on reproduction was provided by Jobling et al. (2003).

Additional information

Jobling et al. (2003) provided reliable toxicity test data for a 9 week octylphenol exposure to the snail Potamopyrgus antipodarum results showed the NOEC for survival and reproduction to be 0.1 mg octylphenol/L. This was the only reliable study found and selected as a key study for toxicity of octylphenol to other aquatic organisms.