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

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

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

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.694 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

1.48 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 1.0-2.7

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

< 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

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

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 1989-04-03 to 1989-04-06

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Algal growth inhibition test according to UBA (Feb. 1984)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 1 g of the test item was stirred for 18 hours and subsequently filtered. This solution served as stock solution. The concentration of the test substance was measured to be 7.65 mg/L (determination of TOC).

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: Scenedesmus subspicatus CHODAT (86.81 SAG)
- Source (laboratory, culture collection): Original culture from "Institut für Wasser-, Boden- und Lufthygiene", Berlin, Germany, subsequently in-house breeding
- Age of inoculum (at test initiation): 3 days
- Method of cultivation: in sterile-aerated Erlenmeyer flasks on light benches

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no post exposure observations made

Hardness:

no data

Test temperature:

no data

pH:

no data

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

0 / 0.306 / 0.497 / 0.841 / 1.339 / 2.295 / 3.82 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: aerated Erlenmeyer flasks
- Initial cells density: approx. 20 000 cells/mL
- Control end cells density: not measured
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


GROWTH MEDIUM
- Standard medium used: no data


TEST MEDIUM / WATER PARAMETERS
no data


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuously
- Light intensity and quality: no data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
Measurement of turbidity of the cell suspensions after 24, 48 and 72 hours
- Chlorophyll measurement: no


TEST CONCENTRATIONS
- Spacing factor for test concentrations: no data

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no details mentioned
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: not applicable

Results with reference substance (positive control):

no reference substance tested

Reported statistics and error estimates:

no statistics performed

Table: Mean values of the turbidity of the cell suspensions in relation to the exposure time and test substance concentrations

concentration [mg/L]	turbidity of cell suspensions after
	0 h*	24 h	48 h	72h
control	0.3	1.9	5.5	17.9
0.306	0.3	1.7	5.7	19.4
0.497	0.3	1.8	5.5	17.5
0.841	0.3	1.6	4.2	10.0
1.339	0.3	1.2	2.4	3.3
2.295	0.3	0.8	1.8	1.6
3.82	0.3	0.6	1.8	1.9

* theoretical value after 0 hours

Validity criteria fulfilled:

not specified

Conclusions:

On the basis of cell growth, a mean effective concentration could be calculated to EbC50 (72 h) = 1.3 mg/L.
10% inhibition on cell growth was calculated to EbC10 (72 h) = 0.5 mg/L and 90% inhibition to EbC90 (72 h) = 3.2 mg/L.

Executive summary:

Green algae (Scenedesmus subspicatus) were exposed to several concentrations of Nonylphenol to determine the inhibition of growth in relation to an untreated control culture over several generations of this algae. The mean values of the turbidity of the cell suspensions as a comparison for the cell concentrations were plotted against the exposure time to produce growth curves. From the comparison of the areas under the growth curves, the percentage of inhibition rates were calculated for each concentration. The EC values for the growth curves could be calculated from the present data by probit analysis according to Cavalli-Sforza.

From the derived data of this study the following values were established:

On the basis of cell growth, a mean effective concentration was calculated to be EC50 (72 h) = 1.3 mg/L.

10% inhibition on cell growth was calculated to EC10 (72 h) = 0.5 mg/L, 90% inhibition to EC90 (72 h) = 3.2 mg/L..

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not provided

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Klimisch 1d. 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: Stephan et al (1985) Guidelines for deriving numerical national water quality criteria for the protection of aquatic organisms and their uses. EPA PB 85-2270

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

other: ASTM (1991b) Standard guide for conductiong static 96-hr toxicity tests with algae. ASTM Annual Book of Standards 11.04:1218-90

Deviations:

no

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: stock solutions generated with a liquid/liquid equilbrator
- Controls: dilution water control

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Source: green algae inoculum obtained from Carolina Biological Supply Inc, Burlington NC
- Age of inoculum: unknown
- Method of cultivation: in aseptically prepared standard nutrient media placed in 4L flask, aerated and stirred by magnetic stirrer for 7-10 days.
- Certifuged to concentrate and supernatant decanted. Cells resuspended in small volume of media solution and quantified using a haemocytometer in order to prepare solutions of required cell density.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

16.0 mg/L as CaCO3

Test temperature:

25.7 +/-0.2 °C

pH:

7.49 +/- 0.12

Nominal and measured concentrations:

- Test concentrations: 7 concentrations (which ranged in mean measured values from 0.0266 to 2.72 mg/L). Concentrations were measured in surrogate test chambers at 0, 48 and 96 h

Details on test conditions:

TEST SYSTEM
- Test vessel: 300 ml Erlenmeyer flasks
- Type: closed
- Material, size, headspace, fill volume: 100 ml sterile nutient media incubated on shaker table
- Initial cells density: 2 x 10^5 /mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
A fourth replicate for the control and test concentrations was added as a surrogate for chemical determinations to avoid removing algae during sampling

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionized water with salts and nutrients incorporated
- Alkalinity: 54.0 mg/L as CaCO3
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Photoperiod: 16L:8D
- Light intensity and quality: 218 ftc

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: at end of test flask contents were filtered, rinsed, oven dried and weighed.

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.694 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

1.48 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Flocculation: accounted for

Reported statistics and error estimates:

- NOEC and LOEC determined by one-way analysis of variance (ANOVA)

Validity criteria fulfilled:

yes

Conclusions:

The NOEC for inhibition of cell production was 0.694 mg nonylphenol/L. The LOEC for inhibition of cell production was 1.48 mg nonylphenol/L. No further conclusions drawn.

Executive summary:

Brooke (1993).EPA.: Klimisch 1. 

In a 96-hour acute toxicity study, the cultures of Selenastrum capricornutum (Carolina Biological supply) were exposed to nonylphenol at mean measured test concentrations of 0.0266, 0.0667, 0.136, 0.329, 0.694, 1.480, and 2.720 mg nonylphenol/L under static conditions following U.S. EPA guidelines. The NOEC for inhibition of cell production was 0.694 mg nonylphenol/L. The LOEC for inhibition of cell production was 1.48 mg nonylphenol/L. The % growth inhibition in the treated algal culture as compared to control ranged from 70 to 100 percent. 

 

There were no compound related phytotoxic effects.

 

This toxicity study is classified as acceptable and satisfies the guideline requirements for a supporting acute Selenastrum capricornutum toxicity test. The NOEC and LOEC values reported in Brooke (1993) are not comparable toEC₅₀and other point estimates of effects. The NOEC and LOEC information is provided to support the findings in key studies Scholz (1992) and Ward and Boeri (1990).

 

Results Synopsis

 

Test Organism:Selenastrum capricornutum

Test Type: Static

 

96 hrEC₅₀:  none                                95% C.I.:  none

96 hr EC₅₀/IC₅₀: none                         95% C.I.:  none

NOEC: 0.694 mg nonylphenol/L         Probit Slope:  none

LOEC: 1.48 mg nonylphenol/L 

Endpoint(s) Effected:  Dry wt. biomass/Growth Inhibition

 

This study was selected as a supporting study because nonylphenol toxicity information is presented for a common aquatic plant species other than algae in addition to the algae Selenastrum capricornutum. Results of this study support the finding of Key Study 2 Ward and Boeri (1990).

Reference 4

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 10 -14, 1984

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guidelines Study, however, test concentrations were not measured

Qualifier:

according to guideline

Guideline:

other: ASTM E47.01 1983. Proposed Standard Practice for Conducting Short-term Toxicity Tests with Fresh Water and Salt Water Algae

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

NA

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg of OP was diluted with solvent
- Controls: dilution water and solvent controls present
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): triethylene glycol
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 0.1 ml

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: algae
- Source (laboratory, culture collection): lab culture maintained at ABC Labs, originally obtained from American Type Culture Collection Rockville, MD
- Age of inoculum (at test initiation): 7-10 days

ACCLIMATION
- Acclimation period: none as inhouse lab culture
- Culturing media and conditions (same as test or not): same

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

not provided

Test temperature:

24-25 °C

pH:

7.5 s.u.

Dissolved oxygen:

not provided

Salinity:

NA

Nominal and measured concentrations:

nominal: 0, 0, 1.0, 1.8, 3.2, 5.6, 10 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml Erlenmeyer flask
- Material, size, headspace, fill volume: 100 ml
- Initial cells density: 2000000 +/- 10%
- Control end cells density: 900000 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: filtered dionized water with added salts to prepare standard nutrient medium
- Total organic carbon: <0.1 mg/L

OTHER TEST CONDITIONS
- Sterile test conditions: yes/no
- Adjustment of pH: yes to 7.5 s.u. if needed
- Photoperiod: 24 h
- Light intensity and quality: "cool-white" light 400-410 ftc

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): growth at end of test
- Determination of cell concentrations: not provided

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0.01, 0.1, 1.0, 10 mg/L
- Results used to determine the conditions for the definitive study: yes

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 1.0-2.7

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

< 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Reported statistics and error estimates:

EC50 calculated by Probit Method, NOEC calculated by using ANOVA p=0.05

Validity criteria fulfilled:

yes

Conclusions:

Study authors make not formal conclusions.

Executive summary:

In a 96 hour acute toxicity study, the cultures of the algae, Selenastrum capricornutum were exposed to octylphenol at nominal test concentrations of 1.0, 1.8, 3.2, 5.6, and 10 mg octylphenol/L under static in accordance with ASTM 1983 guidelines. The EC₅₀value based on cell density 1.9 mg octylphenol/L. 

 

This study is classified as acceptable and satisfies the guideline requirements for toxicity study with algae.

 

Results Synopsis

 

Test Organism: Selenastrum capricornutum

Test Type: Static

 

96 hrEC₅₀:  1.9 mg octylphenol/L                   95% C.I. :  1.0 -2.7

NOEC:   <1.0 mg/L octylphenol                     Endpoint(s) Effected:  Density/Growth inhibition

 

ABC Labs (1984) was selected as a key study because it provides EC₅₀ toxicity information on the sensitivity of a common algal test species to octylphenol and it is a preferred study among the algae test results. The test results provide an inhibition of cell growth (EC₁₀) estimate of 0.1.9 mg octylphenol/L. 

Description of key information

EC50 for growth inhibition of Pseudokirchneriella subcaptitata is 1.9 mg octylphenol/L. 

Key value for chemical safety assessment

EC50 for freshwater algae:

1.9 mg/L

Additional information

A study by ABC Labs (1984) on effects of a 96 hr exposure of octylphenol to the freshwater algae Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum) was found reliable and selected as a key study. Results of the test showed the EC50 for growth inhibition of Pseudokirchneriella subcaptitata to be 1.9 mg octylphenol/L.