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

Toxicity to birds

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to birds: reproduction test

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

Duration (if not single dose):

7 wk

Dose descriptor:

NOEL

Effect level:

100 other: nmol/g bw/d

Conc. / dose based on:

test mat.

Basis for effect:

reproductive parameters

Remarks on result:

other: No data

Repellency factors (if applicable):

No data

The following endpoints were recorded:

- Egg production and latency of communally housed birds;

- Cracked/Broken Eggs of Communally Housed Birds;

- Dead Embryos of Communally Housed Birds; and

- Hatched Eggs of Communally Housed Birds.

There was no significant effect of octylphenol (at 100 nmol/g) to any of these endpoints.

Validity criteria fulfilled:

yes

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 birds. Based on the information available for the read across substances, the substance is not expected to be toxic to birds.

Reference 2

Endpoint:

long-term toxicity to birds: reproduction test

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Meets national standard methods with acceptable restrictions which do not impair the overall conclusion from the data. The use of the non-standard test species means the method has been adapted to accommodate the non-standard species (Zebra Finch) which is smaller and has a shorter lifecycle than the larger more standard test species.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 206 (Avian Reproduction Test)

Deviations:

yes

Remarks:

University Protocol was approved by the University of California Davis Institutional Animal Use and Care Committee. The method differed from the OECD 206 Guideline in relation to the test species, Zebra Finch. This is a smaller bird with a shorter lifecy

Principles of method if other than guideline:

Not applicable

GLP compliance:

not specified

Specific details on test material used for the study:

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

Dose method:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Details on preparation and analysis of diet:

DIET PREPARATION
- Description and nutrient analysis of basal diet provided in study report: yes - finches were offered Finch Supermized bird seed (Volkman Seed Company, Ceres, California, USA) ad libitum and water was freely available. Birds were additionally given ground-up boiled egg twice per week (approximately 15 g per breeding pair).
- Preparation of doses: The dosage was 1 µg/g body mass of 100 nmol octylphenol was prepared resulting in 100 nmol/g of body mass per day of octylphenol.

HOMOGENEITY AND STABILITY OF TEST MATERIAL IN DIET
- How often was homogeneity and stability tested: No data.

Test organisms (species):

other: Taeniopygia guttata

Details on test organisms:

TEST ORGANISM
- Common name: Zebra Finch
- Source: University of California's Department of Animal Science's random-bred colony. The colony was founded from local avicultural stock of wild-type phenotype.
- Age at test initiation (mean and range, SD): 130 to 180 days of age
- Sexes used: Male and Female used
- Kept according to standard practices: yes
- Breeding population (e.g. reproductive history): Water in a shallow (4 cm deep) dish was provided for bathing 1 day per week. Wooden dowels were provided as perches. The photoperiod was 16 h light:8 h dark; room temperature was approximately 21 °C. Humidity was not regulated but was typically within the range of 40 to 70% relative.
Experimental birds were reared by their parents in individual pair breeding cages (46 x 46 x 46 cm) until approximately 45 days of age and then transferred to mixed-sex cages containing from 6 to 20 birds, each. Experimental trials were conducted in communal cages (0.9 x 0.9 x 1.8 m) or in individual pair breeding cages, as indicated. Birds were induced to breed by providing sheet metal nest boxes (15 x 15 x 13 cm), eight per communal breeding cage or one per individual breeding cage. Supplying more nest boxes than is minimally necessary in communal caging is common avicultural practice to reduce competition for nesting sites. Shredded burlap was provided in nest boxes for nest construction. Nests were checked daily, by an experimentally blind observer, for eggs and chicks, and eggs were candled at weekly intervals to determine candled fertility during the incubation period.

Limit test:

no

Total exposure duration (if not single dose):

7 wk

Post exposure observation period:

No data

No. of animals per sex per dose and/or stage:

- 5 females and 5 males and repeated once for an N of 10 total pairs per treatment.

Control animals:

yes, concurrent vehicle

Nominal and measured doses / concentrations:

- The dosage was 1 µg/g body mass of 100 nmol octylphenol resulting in 100 nmol/g of body mass per day of octylphenol.

Details on test conditions:

ACCLIMATION
- Acclimation period: Finches aged between 130 and 180 days of age were introduced into communal cages (five females and five males) or were force paired in individual breeding cages.

Duration (if not single dose):

7 wk

Dose descriptor:

NOEL

Effect level:

100 other: nmol/g bw/d

Conc. / dose based on:

test mat.

Basis for effect:

reproductive parameters

Remarks on result:

other: No data

Repellency factors (if applicable):

No data

The following endpoints were recorded:

- Egg production and latency of communally housed birds;

- Cracked/Broken Eggs of Communally Housed Birds;

- Dead Embryos of Communally Housed Birds; and

- Hatched Eggs of Communally Housed Birds.

There was no significant effect of octylphenol (at 100 nmol/g) to any of these endpoints.

Validity criteria fulfilled:

yes

Conclusions:

The authors studied short-term, posthatch oral exposure to estrodiol benzoate (EB) and octylphenol. No adverse effects of OP treatment were detected. The significant treatment effects (all P < 0.05) due to EB show that posthatch EB treatment profoundly disrupts the reproductive performance of zebra finches, suggesting that exposure to estrogens in the wild could impair the reproductive performance of wild populations.

Executive summary:

A study was performed to assess the effect of the test substance octylphenol on reproductive success in zebra finches. The method used followed that described in the OECD Guidelines for Avian Toxicity, although modified using a reduced duration for the smaller non-standard bird species. A NOEL of 100 nmol octylphenol per gram of body mass was reported for all the endpoints tested, including number of eggs hatched.

Description of key information

No reliable short-term data were available specifically relating to birds. However, the key study by Millam et al (2001) reported a NOEL of 100 nmol/g bw/d, which converts to a NOEC of 70.8 mg/kg food based on Zerba Finch (Taeniopygia guttata) reproductive endpoints.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for birds:

70.8 mg/kg food

Additional information

No reliable short-term data were available specifically relating to birds. However, the key study by Millam et al (2001) reported a NOEL of 100 nmol/g bw/d, which converts to a NOEC of 70.8 mg/kg food based on Zerba Finch (Taeniopygia guttata) reproductive endpoints. The methodology does deviate from standard test guidelines, particularly in relation to the duration of the study which was reduced because of the smaller bird species (a non-standard species). However, the study is deemed to be reliable with restriction for REACH assessment as it is indicative of avian toxicity.