4-chloro-3,5-xylenol

Toxicity to reproduction

Administrative data

Endpoint:

reproductive toxicity, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

Version / remarks:

GUIDELINE REFERENCE NO. 83-3

Deviations:

not specified

GLP compliance:

yes

Justification for study design:

This study was performed to detect and evaluate the potential
embryo toxic or teratogenic effects of the test article, 4 chloro 3, 5 xylenol
(PCMX.), when administered orally to pregnant rats during the period of major
organogenesis.
This report details experimental procedures and results of a teratology
study in rats treated with 4 chloro 3,5 xylenol (PCMX). This study was
performed to detect and evaluate the potential embryotoxic or teratogenic
effects of the test article when administered orally to pregnant rats during
the period of organogenesis. The Sprague-Dawley rat was selected as the
experimental model since it is recommended by the Environmental ProtectiQn
Agency (EPA) as a suitable species for teratology studies.

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-3,5-xylenol

EC Number:

201-793-8

EC Name:

4-chloro-3,5-xylenol

Cas Number:

88-04-0

Molecular formula:

C8H9ClO

IUPAC Name:

4-chloro-3,5-dimethylphenol

Test material form:

solid: crystalline

Details on test material:

Sponsor's identification
Description
Batch number
Date received
Storage conditions
PCMX
cream coloured, crystalline solid
285/13847
27 September 2001
room temperature, in the dark

Specific details on test material used for the study:

Test and Control Articles
l. Test Article
The test article was received at SLS and identified as follows:
Assigned
Sponsor's ID SLS ID
4 chloro 3,5 590.002.3227
xylenol (PCMX)
USP Grade
Lot No. Wl43-l
Physical
Description
Off-White
Crystalline
Powder
Receipt
Date
September 12, 1990
A reserve 5 g sample of the test article was taken and stored at
SLS. The reserve sample and bulk compound were stored at room temperature.
The Sponsor is responsible for any necessary evaluations related to chemical
identification, purity, strength and stability of the test article.
2. Test Control (Vehicle) Article
The vehicle control article for this study was corn oil. The corn
oil was supplied by Best Foods, Englewood Cliffs, NJ, as follows:
Assigned Receipt
Control Article Lot No. SLS ID Date
Mazola• Corn Oil JUL1691A V90.022 November 5, 1990

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

One hundred twenty-eight Sprague-Dawley Crl:CD~BR VAF/Plus~ rats
were received at SLS on December 27, 1990 from Charles River Laboratories,
Inc., Portage, MI, for use in this study. At the time ~f receipt, each rat
was identified with a metal ear tag displaying an unique number. ~nirnals
were housed individually during acclimation and while on study (except
during cohabitation for mating) in suspended stainless steel cages.

Sex:

female

Details on test animals or test system and environmental conditions:

At the conclusion of acclimation, the animals were weighed and
examined. Females determined to be suitable test subjects based on age:
healthy appearance, and body weight, were cohabitated with proven resident
Sprague-Dawley Crl: CD®BR VAF /Plus® male rats. At the initiation of
breeding, all females were approximately 90 days of age with body weights
ranging from 222 to 283 g. Evidence of mating was determined by the
presence of a copulatory plug in the vagina or a sperm positive vaginal
smear. The day evidence of copulation was confirmed was designated as day
0 of gestation. At that time, the female rats were assigned consecutively,
in a block design, to study groups. Gestation day 0 body weights ranged
from 220-291 g.

Administration / exposure

Route of administration:

oral: gavage

Type of inhalation exposure (if applicable):

not specified

Vehicle:

corn oil

Details on exposure:

Dosage solutions were administered orally by gavage as a single dose
daily from gestation day 6 through gestation day 15. Oral administration
of the test article was selected since this is a potential route of human
exposure. Individual doses were adjusted based on the most recent body
weight data.

Details on mating procedure:

At the conclusion of acclimation, the animals were weighed and
examined. Females determined to be suitable test subjects based on age:
healthy appearance, and body weight, were cohabitated with proven resident
Sprague-Dawley Crl: CD®BR VAF /Plus® male rats. At the initiation of
breeding, all females were approximately 90 days of age with body weights
ranging from 222 to 283 g. Evidence of mating was determined by the
presence of a copulatory plug in the vagina or a sperm positive vaginal
smear. The day evidence of copulation was confirmed was designated as day
0 of gestation. At that time, the female rats were assigned consecutively,
in a block design, to study groups. Gestation day 0 body weights ranged
from 220-291 g.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Prestudy analytical chemistry evaluations indicated that 4 chloro 3,5
xylenol (PCMX) was homogeneous and stable in corn oil for up to eight days
when stored at room temperature. Analysis of dosage preparations resulted
in average test article recoveries ranging from 9S.S to 103.0% indicating
that the preparations were accurately prepared.

Duration of treatment / exposure:

The in-life phase of the study was initiated with the assignment of mated
female rats to study groups on January 8, 1991 (gestation day 0) and
concluded with terminal sacrifice on February 4, 1991 (gestation day 20).

Frequency of treatment:

Dosage solutions were administered orally by gavage as a single dose
daily from gestation day 6 through gestation day 15. Oral administration
of the test article was selected since this is a potential route of human
exposure. Individual doses were adjusted based on the most recent body
weight data.

Details on study schedule:

At the initiation of
breeding, all females were approximately 90 days of age with body weights
ranging from 222 to 283 g.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Remarks:

Dosage solutions were administered orally by gavage as a single dose daily from gestation day 6 through gestation day 15. Oral administration of the test article was selected since this is a potential route of human exposure. Individual doses were adjusted based on the most recent body weight data.

Doses / concentrations 2

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Remarks:

Dosage solutions were administered orally by gavage as a single dose daily from gestation day 6 through gestation day 15. Oral administration of the test article was selected since this is a potential route of human exposure. Individual doses were adjusted based on the most recent body weight data.

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

Dosage solutions were administered orally by gavage as a single dose daily from gestation day 6 through gestation day 15. Oral administration of the test article was selected since this is a potential route of human exposure. Individual doses were adjusted based on the most recent body weight data.

No. of animals per sex per dose:

25f

Control animals:

yes, concurrent no treatment

Details on study design:

This report details experimental procedures and results of a teratology
study in rats treated with 4 chloro 3,5 xylenol (PCMX). This study was
performed to detect and evaluate the potential embryotoxic or teratogenic
effects of the test article when administered orally to pregnant rats during
the period of organogenesis. The Sprague-Dawley rat was selected as the
experimental model since it is recommended by the Environmental ProtectiQn
Agency (EPA) as a suitable species for teratology studies.

Positive control:

n/a

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical signs were generally unremarkable at the 100 mg/kg/day level,
although a slightly higher incidence of mucoid stools, soft stools and few
feces was observed. Similar signs of gastrointestinal disturbance occurred
at a higher incidence and in a dose-related pattern at the SOO and 1000
mg/kg/day levels. Additional signs of toxicity at the 1000 mg/kg/day level
included decreased activity, shallow breathing, cool to the touch, no feces,
diarrhea, and dark material around the nose and/or mouth. These more severe
clinical signs occurred primarily in females that subsequently died. In
contrast to these changes, clinical observations in control females were
limited to occasional signs of gastrointestinal disturbance which were
attributable to the vehicle, corn oil.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Additional signs of toxicity at the 1000 mg/kg/day level
included decreased activity, shallow breathing, cool to the touch, no feces,
diarrhea, and dark material around the nose and/or mouth. These more severe
clinical signs occurred primarily in females that subsequently died.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean maternal body weight gain at the 500 mg/kg/day level was
statistically lower than the control group during gestation days 12-16. At
the 1000 mg/kg/day level, statistically significant body weight loss
occurred during gestation days 6-9 and statistically reduced weight gain was
noted during gestation days 12-16, 6-16 and 0-20. In addition, net maternal
body weight gain was statistically reduced at the 1000 mg/kg/day group when
compared to the control group. No adverse body weight effects were noted
at the 100 mg/kg/day level.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption calculated as grams/animal/day was statistically
reduced at the 500 mg/kg/day level during gestation days 6-9, 12-16 and 6-
16. At the 1000 mg/kg/day level, food consumption was statistically reduced
during gestation days 6-9, 9-12, 12-16, 6-16 and 0-20. Food consumption at
the 100 mg/kg/day level was similar to the control group throughout the
study.

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Effect levels (P0)

Key result

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

reproductive performance

Remarks on result:

other: not toxic

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not specified

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

not examined

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Details on results (F1)

n/a

Effect levels (F1)

Dose descriptor:

other: not examned

Generation:

F1

Effect level:

0 other:

Based on:

not specified

Sex:

not specified

Basis for effect level:

other:

Remarks on result:

not measured/tested

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Lowest effective dose / conc.:

100 mg/kg bw/day (actual dose received)

Treatment related:

yes

Relation to other toxic effects:

not specified

Dose response relationship:

yes

Relevant for humans:

yes

Any other information on results incl. tables

Maternal toxicity was produced by 4 chloro 3,5 xylenol (PCMX) at the

500 and 1000 mg/kg/day levels. At the 1000 mg/kg/day level, treatrnentrelated

effects consisted of mortality in 5 of 25 females, adverse clinical

signs, and decreased weight gain and food consumption. Similar but less

pronounced effects were observed at the 500 mg/kg/day level where no

maternal mortality occurred. At the 100 mg/kg/day level, there were no body

weight or food consumption effects. An apparent slight increase in the

occurrence of clinical signs, which were similar to controls, was noted at

the 100 mg/kg/day level. It was not clear whether these signs were

influenced by 4 chloro 3,5 xylenol (PCMX) or due to the corn oil vehicle.

Evaluation of cesarean section parameters revealed no differences among the

groups concerning the mean number of corpora lutea, implantation sites,

viable fetuses, fetal sex ratios, gravid uterus weights and fetal body

weights. A marginal increase in mean post-implantation loss was observed

at the 1000 mg/kg/day level where excessive maternal mortality occurred.

This difference was not statistically significant and remained within the

SLS historical control range. · No treatment-related malformations or

developmental variations were noted in the study.

Applicant's summary and conclusion

Conclusions:

Based on the results of this study, a dosage level of 100 mg/kg/day was
considered a no-adverse-effect level for maternal toxicity. A dosage level
of 1000 mg/kg/day was considered a no-observed-effect level for fetal
toxicity and teratogenicity.