Biphenyl-4,4'-diyl tetraphenyl bis(phosphate)

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Well documented and reported study fully adequate for assessment. The study was conducted according to an internationally accepted technical guideline and in compliance with GLP in a recognized contract research organization. Read across of reproduction and developmental toxicity data is considered to be appropriate, because the chemical structures of the substance target chemical, ADK STAB FP 800, and the substance analogue source chemical, EC No. 425-220-8, are almost identical and the results from available equivalent physicochemical, toxicological and ecotoxicological studies with these two substances are compatible (see Attachment "read-across justification").

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test) of 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

425-220-8

EC Name:

-

IUPAC Name:

425-220-8

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Wistar rats, strain: Wistar HAN(TM):HsdRCCHHan(TM):WIST with appropriate range of bodyweight at study start.
- Source: Harlan Laboratories UK Ltd.
- Age at study initiation (treatment start): Ca. 12 weeks.
- Weight at study initiation (treatment start): Males: minimum 312 g, maximum 364 g,
Females: minimum 196 g, maximum 248 g.
- Housing
all animals, before pairing: In groups of 5 by sex in solid floor propylene cages with stainless steel mesh lids.
during pairing (1 male+1 female/cage): In propylene grid-floor cages suspended over absorbent paper-lined trays.
after pairing: Males returned to their initial cages,
during gestation and lactation: Females housed individually in solid floor propylene cages with stainless steel mesh lids.
- Bedding (all animals, except during pairing): Softwood flake bedding (Datesand Ltd, Cheshire, UK).
- Environmental enrichment,
except during gestation/lactation: Wooden chew blocks and cardboard fun tunnels (Datesand Ltd, Cheshire, UK).
- Diet (ad libitum): Commercially available pelleted diet:
Rodent 2018C Teklad Global Certified Diet, Harlan Laboratories UK Ltd.
- Water (ad libitum): Mains drinking water
- Acclimation period: 14 days before treatment start

ENVIRONMENTAL CONDITIONS
The animal room was maintained at (target ranges for temperature and relative humidity):
- Temperature (°C): 21 ± 2°C
- Relative Humidity (%): 55 ± 15%
- Photoperiod (low intensity fluorescent lighting): 12 h day / 12 h night
- Rate of air exchange: At least 15 changes/h
Slight deviations from these targets were considered not to have affected the purpose or integrity of the study.

IN-LIFE DATES:
- Duration of Pre-pairing treatment: 14 days
- Duration of Pairing (until conception): 1 to 5 days
- Duration of Gestation: 22 to 23.5 days

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

400

Details on exposure:

Treatment of parental animals by oral gavage administration. Test substance was not directly administered to F1 animals, as these pups were sacrificed on day 5 post partum, i.e. day 5 of lactation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Chemical analysis of test material formulations by high performance liquid chromatography (HPLC) using an external standard technique.
- Concentrations (verified at weekly intervals) of the test material formulations were confirmed at each dose level and homogeneity and stability at
the low and top dose level.
- Chemical analysis confirmed that the prepared formulations were within ± 3% of the corresponding nominal concentration.

Details on mating procedure:

- Male/female ratio per cage: 1/1
- Length of cohabitation: 1 to 5 days, as by then 10 females/group had shown evidence of copulation.
- Proof of pregnancy: Formation of vaginal plug in situ or sperm in vaginal smear referred to as day 0 of gestation.
During cohabitation, cage tray-liners were checked each morning for the presence of ejected copulation plugs and females for pregnancy.

Duration of treatment / exposure:

- Treatment period, parental males: Once daily until termination on Day 43 of the study.
Treatment period, parental females: Up to 46 days (from 14 days prior to mating to Day 5 of lactation)
- Duration of Pre-pairing treatment: 14 days

Frequency of treatment:

Once daily (except for females during parturition where applicable)

Duration of test:

- Duration of test, parental males: 43 days
Duration of test, parental females: From 14 days prior to mating to Day 5 post partum (Day 5 of lactation)
Duration of test, pups: Until Day 5 of lactation.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Examinations

Maternal examinations:

Clinical observations performed and frequency:
- Clinical signs: At least three times a day (just before and at regular intervals after administration)
- Body weight, Males: Once a week
Body weight, Females: Once a week for pre-mating and mating period, on Days 0, 7, 14, 20 of gestation and on Days 1 and 4 of lactation.
- Food consumption, Males: Once a week during the pre-mating period and after the mating period.
Food consumption, Females: Once a week during the pre-mating period, for Days 0-7, 7-14 and 14-20 of gestation and for Days 1-4 of lactation.
- Food efficiency: (bodyweight gain/food intake) was calculated retrospectively during pre-maiting and Weeks 1 and 2 of gestation.
- Water consumption: Daily (visual inspection of water bottles for overt changes for each cage group)
- Frequency of vaginal estrus was determined during the mating period until the day of confirmed copulation.

Additional parameters examined:
- Pre-coital interval (time, i.e. no. of days, elapsing between initial pairing and positive evidence of maiting).
- No. of pairs mated.
- No. of living pregnant females.
- No. of females delivering live pups.
- Gestation length , i.e. no. of days including the days of positive evidence of mating, gestation and parturition start
- No. of pregnant females with live pups on lactation days 0, 1 or 4
- Sperm parameters examined in male parental animals:
testis weight,
epididymis weight,
degree of the presence of sperm in vaginal smears by assignment of 3 grades as part of the copulation check

Ovaries and uterine content:

The ovaries and uterine content were examined after termination on day 5 of lactation, i.e. day 5 post partum.
Examinations included:
- Number of corpora lutea: Yes
- Number of implantation sites: Yes

In addition, gestation length calculated from day 0 of pregnancy was recorded for all female animals, and reproductive organs were histopathologically examined in all control and high dose group animals.

Fetal examinations:

Litters were examined post partum as follows (day of birth = day 0):

- No. of pups alive and dead: day 0 (on completion of parturition), afterwards daily recording of number of live offspring
- Sex ratio (% males) for each litter: days 0, 1 and 4
- Clinical signs/condition: days 0 to 5, at least once daily
- Assessment of surface righting reflex: day 1
- Individual bodyweight and litter weight: days 1 and 4.
- Bodyweight gain: days 1 to 4
- Necropsy:  full external and internal gross pathology of all pups (terminal sacrifice and interim deaths)

Statistics:

Bodyweight and bodyweight change, food consumption for females during gestation and lactation, litter data, sex ratios, implantation losses and viability indices, offspring bodyweight and bodyweight change, offspring surface righting, adult absolute organ weights and organ to bodyweight ratios were assessed by linear regression analysis (for dose response relationships) followed by one way analysis of variance (ANOVA) incorporating Levne’s test for homogeneity of variance.
- Where variances were shown to be homogeneous pairwise comparisons were made using Dunnett’s test.
- Where Levene’s test showed unequal variances the data were analysed non- parametrically using Kruskal-Wallis ANOVA and Mann-Whitney “U’ test.

The non-parametric methods were also used to analyse implantation loss and offspring sex ratios and landmark developmental markers.

Indices:

- Mating index (No. of animals mated / No. of animals paired x 100)
- Pregnancy index (No. of pregnant females / No. of females mated x 100)
- Gestation length , i.e. no. of days including the days of positive evidence of mating, gestation and parturition start
- Parturition index (No. of females delivering live pups / No. of living pregnant females x 100)
- % Pre-implantation loss [(No. of corpora lutea – No. of implantation sites) x 100 / No. of corpora lutea]
- % Post-implantation loss [(No. of implantation sites – No. of live pups) x 100 / No. of implantation sites]
- Live birth index (No. of live pups on day 1 / No. of pups born on day 0 x 100)
- Viability index (No. of live pups on day 4 / No. of live pups on day 1 x 100)
- Sex ratio (% males) for each litter on days 0, 1 and 4
- Post natal loss of pups (live births minus pups alive on day 4)

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Effect levels (maternal animals)

1

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Findings not Attributable to Treatment with the Test Material:
- At terminal kill in one mid dose pup a right testis, left uterine horn and ovary was present. The ovary was enlarged and dark.
In addition, there were 3 interim deaths in the high dose group and 1 in the vehicle control group, of which 2 high dose pups and the control pup
were autolytic and the other high dose pup was without macroscopic abnormalities.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

There were no relevant effects attributable to treatment with the test material. The no observed effect level (NOEL) for maternal and foetal toxicity is
1000 mg/kg bw/day.