Phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutylene

Endpoint summary

Description of key information

Repeated dose toxicity of phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutylene was tested in two studies with male and female rats (oral feed), during 28 and 90 days.

A NOAEL of 32 mg/kg bw/d was derived from the 90-day study based on increased activated partial thromboplastin time and increased liver weights in males.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 1989 - July 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Performed in accordance with a common test guideline (at the time) in compliance with GLP

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

no urinalysis

Principles of method if other than guideline:

not applicable

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Crl:CD BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Fortage, Michigan
- Age at study initiation: 7 weeks
- Weight at study initiation: Males: 176-379 g; Females: 146-185 g
- Fasting period before study: no
- Housing: individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 67 – 75 ◦F (19 – 24 ◦C)
- Humidity (%): 38-90
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: March 22, 1989 To: July 7, 1989

Route of administration:

oral: feed

Vehicle:

other: diet

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: not applicable

DIET PREPARATION
- Rate of preparation of diet (frequency): diet preparation was performed at least twice during the study, because the methodology was revised as from week 7. However, the actual frequency of diet preparation remains unclear
- Mixing appropriate amounts with (Type of food): rodent meal
- Storage temperature of food: not described

VEHICLE
- Justification for use and choice of vehicle (if other than water): not provided
- Concentration in vehicle: : 500,1500, 4500 ppm in diet
- Amount of vehicle (if gavage): not applicable
- Lot/batch no. (if required): 809191 (test compound)
- Purity: 100% (test compound)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

homogeneity and concentration of substance in diet was determined by HPLC analysis

analytical conditions:
Hitachi HPLC system with UV-detector and autosampler
column: Alltech Mixed mode RP-18/cation, 7 micron
mobile phase: water; acetonitrile (15:85)
flow rate: 1 ml/min
detction: UV at 280 nm
injection volume: 10 uL
internal standard: tri-t-butylphenol
standard solutions in 2-propanol

Wingstay L consists of several components, therefore the integrator was programmed to sum the areas of all relevant peaks and to calculate and report them as 1 peak.

Duration of treatment / exposure:

91-92 days

Frequency of treatment:

continuous, via diet

Remarks:

Doses / Concentrations:
500,1500, 4500 ppm
Basis:
nominal in diet

No. of animals per sex per dose:

15 males and 15 females

Control animals:

yes

Details on study design:

- Dose selection rationale: based on a previously conducted study
- Rationale for animal assignment (if not random): not applicable
- Rationale for selecting satellite groups: not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): not applicable

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations checked in table [No.?] were included. …not applicable

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
- Time schedule for examinations: …not applicable

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to study initiation and in week 12
- Dose groups that were examined: …all animals of all groups

HAEMATOLOGY: Yes
- Time schedule for collection of blood: days 91 or 92 (at termination)
- Anaesthetic used for blood collection: No
- Animals fasted: Yes
- How many animals: 10/sex/group
- Parameters checked in table [No.?] were examined. Standard parameters

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: days 91 or 92
- Animals fasted: Yes
- How many animals: 10/sex/group
- Parameters checked in table [No.?] were examined. Standard parameters

URINALYSIS: No
- Time schedule for collection of urine: not applicable…
- Metabolism cages used for collection of urine: Yes / No / No data Not applicable
- Animals fasted: Yes / No / No data Not applicable
- Parameters checked in table [No.?] were examined. not applicable

NEUROBEHAVIOURAL EXAMINATION: No

OTHER: none

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes

Other examinations:

none

Statistics:

yes

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not specified

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY: One control male with a mechanical injury was sacrificed in week 9. No treatment-related clinical signs
BODY WEIGHT AND WEIGHT GAIN: lower weight gains at 4500 ppm in first treatment week

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): lower food intake at 4500 ppm in first treatment week (considered to be related to palatability)

FOOD EFFICIENCY: no data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study) : no data

OPHTHALMOSCOPIC EXAMINATION: No lesions indicative of a toxic effect were observed

HAEMATOLOGY: increased mean prothrombin time (PT) and activated partial thromboplastin time (APTT) in males at 4500 ppm and non-significant increase of APTT at 1500 ppm in males

CLINICAL CHEMISTRY: No treatment-related findings

URINALYSIS: No data

NEUROBEHAVIOUR: no data

ORGAN WEIGHTS: increased absolute and relative weights of liver and adrenals at 1500 and 4500 ppm

GROSS PATHOLOGY: No treatment-related findings

HISTOPATHOLOGY: NON-NEOPLASTIC: no treatment-related findings

HISTOPATHOLOGY: NEOPLASTIC (if applicable) : not applicable

HISTORICAL CONTROL DATA (if applicable) applied for interpretation of clinical chemistry findings

OTHER FINDINGS: none

Key result

Dose descriptor:

NOAEL

Effect level:

500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

haematology

organ weights and organ / body weight ratios

Key result

Critical effects observed:

no

The higher weights of liver and adrenals at 1500 and 4500 ppm had no morphological correlate and may not be indicative of adverse effects. The increase in APTT was considered to be indicative of an effect on intrinsic clotting factors, which would be an adverse effect. As APTT was already increased at 1500 ppm the possibly correlated higher liver weights are considered as adverse. The low-dose level of 500 ppm (32 mg/kg bw/day) is established as the NOAEL.

conversion ppm to mg/kg bw/day:

500 ppm: male - 32 mg/kg bw/day, female - 38 mg/kg bw/day

1500 ppm: male - 96 mg/kg bw/day, female - 117 mg/kg bw/day

4500 ppm: male - 289 mg/kg bw/day, female - 339 mg/kg bw/day

Conclusions:

A dose level of 500 ppm Wingstay L was considered to be a NOAEL when administered to rats for at least 90 days.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

32 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Klimisch 1 study

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The 28 -day study performed did not result in a clear conclusion regarding NOAEL of phenol, 4 -methyl, reaction products with dicyclopentadien and isobutylene. It was therefore considered as range-finding study for a 90 -day oral feed study. From the results of the 90 -day study it was concluded that the NOAEL for male rats is 32 mg/kg bw/d (female: 38 mg/kg bw/d).

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:

Klimisch 1 study of longest duration

Justification for classification or non-classification

Classification according to the CLP Regulation is not considered appropriate as no deaths, serious morphological changes or functional disturbance at the lower dose levels were observed.