Reaction mass of m-cresol and 2-chloro-m-cresol and 6-chloro-m-cresol

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:

GLP compliant OECD guideline 414 study, tested with the source substance CAS 59-50-7. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4900 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chlorocresol

EC Number:

200-431-6

EC Name:

Chlorocresol

Cas Number:

59-50-7

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-3-methylphenol

Details on test material:

- Name of test material (as cited in study report): Preventol CMK
- Physical state: Solid, colourless powder
- Analytical purity: 100%
- Lot/batch No.: 791
- Stability under test conditions: Was approved by the study sponsor.

Test animals

Species:

rat

Strain:

other: Wistar (Bor:WISW(SPF Cpb))

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: F. Winkelmann, Borchen, Germany
- Age at study initiation: no data
- Weight at study initiation: 186 - 248 g

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5% aqueous tylose solution

Details on exposure:

VEHICLE
- Concentration in vehicle: 3.0, 10.0, 30.0 mg/mL
- Amount of vehicle: 10 mL/kg bw

Analytical verification of doses or concentrations:

yes

Details on mating procedure:

Virgin female rats were mated overnight individually with males. Females revealing vaginal plugs or spermatozoa in vaginal smears in the following morning were designated as being in day 0 of gestation.

Duration of treatment / exposure:

from day 6 to day 15 of gestation

Frequency of treatment:

daily

Duration of test:

20 days (On day 20 of gestation animals delivered by caesarean section)

Doses / concentrations

Remarks:

Doses / Concentrations:
30, 100, 300 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

25

Control animals:

yes, concurrent no treatment

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
From day 0 to 20 of gestation: twice daily (once on weekends and bank holidays)

BODY WEIGHT: Yes
Day 0 p.c.; Days 6 to 15 p.c.: once daily; day 20 p.c.

FOOD CONSUMPTION: Yes
Days of gestation: 0-6, 6-11, 11-16 and 16-20

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organ examined: Uterus weight

OTHER: Water consumption assessment was performed during inspections by visual inspection of the quantities left over.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Other: Individual weights and outward appearance of placentas

Fetal examinations:

Examination of the fetuses included:
Determination of sex, weight, occurrence of malformations discernable from the outside and other findings deviating from standard, occurrence of visceral malformations (investigations of half of the foetuses according to the modified WILSON technique, occurrence of changes in the abdominal and thoracic organs and skeletal system (evisceration and evaluation of the other foetuses according to the DAWSON technique)

Indices:

Sex ratio (m:f)

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes. Remark: at 300 mg/kg bw/d

Details on maternal toxic effects:
No treatment related effects were seen in animals of the 0 and 30 mg/kg bw/d dose group.
CLINICAL SIGNS:
100 mg/kg bw/d: on days 8 and 16 two animals showed laboured breathing
300 mg/kg bw/d: from day 8 post coitum (p.c.). marked clinical signs (rough coat, sunken flanks, bloody muzzle, laboured breathing, reduced mobility, high-stepping gait) were noted. From day 6 p.c. the following signs occurred from about 10 minutes until 1 hour after application: lying on side, somnolence, abdominal position, spastic convulsion. In addition, one animal showed gasped breathing.
MORTALITY:
0 - 100 mg/kg bw/d: no mortalities occurred
300 mg/kg bw/d: Six animals died during the study period, one of them was sacrificed in moribund condition.
FOOD INTAKE:
100 mg/kg bw/d: statistically significant reduced food intake during the application period.
300 mg/kg bw/d: statistically significant reduced food intake during the application and gestation period.
WATER INTAKE:
100 mg/kg bw/d: reduced in one animal on day 9 p.c.
300 mg/kg bw/d: reduced for several animals from day 9 p.c., in some cases lasting for 1-6 days.
URINE/FAECES EXCRETION:
100 mg/kg bw/d: increased urine excretion in some isolated cases from day 9 p.c.; reduced amount of faeces over a period of 1-5 days in several animals from day 9 p.c.
300 mg/kg bw/d: increased urine excretion in several animals from day 8 p.c. for a period of 1-5 days; reduced amount of faeces in several animals from day 8 p.c. (lasting for 1-5 days).
BODY WEIGHT:
100, 300 mg/kg bw/d: body weight gain was reduced during the treatment period. Body weight development during pregnancy as well as corrected body weight gain was statistically significant reduced.
GROSS PATHOLOGY:
0 - 100 mg/kg bw/d: no effects
300 mg/kg bw/d: Of the 6 animals that died or were sacrificed moribund during the study period, 2 and 3 animals had inflated intestines and bloody vaginas, respectively. Additional significant findings were noted in these animals. No findings were observed in the surviving animals of this dose group. For further details see Table 1 under: "Any other information on results".

Effect levels (maternal animals)

1

Dose descriptor:

LOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

3

Dose descriptor:

LOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

4

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes. Remark: at 300 mg/kg bw/d

Details on embryotoxic / teratogenic effects:
EMBRYOTOXICITY:
0 - 100 mg/kg bw/d: No effects
300 mg/kg bw/d: Reduced foetal weight. Due to an increased rate of resorption, the gestation rate and number of foetuses were also reduced.
TERATOGENICITY: No effects.
For further details see Table 2 under: "Any other information on results".

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Table 1: Overview of maternal effects in the prenatal developmental toxicity study

Parameter	Control data		30 mg/kg bw/d	100 mg/kg bw/d	300 mg/kg bw/d	Dose-response + / –
	historical	0 mg/kg bw/d
Number of dams examined	-	25	25	25	25
Clinical signs of toxicity
audible breathing sounds	-	0	0	1	4	+
gasping breathing	-	0	0	1	1	+
bloody lip	-	0	1	0	0	-
rough coat	3	0	0	0	7	+
bloody muzzle	1 (nose)	0	0	0	4	+
sunken flanks	1	0	0	0	3	+
reduced motility	-	0	0	0	2	+
abdominal knots	-	0	1	0	0	−
bloody forelimbs	-	0	0	0	1	−
high-stepping gait	-	0	0	0	1	+
reduced water intake	7#	0	0	1	12	+
light-brown, hard faeces	4	1	0	0	0
small amount of faeces	4	0	0	4	14	+
increased urine excretion	5#	0	0	3	9	+
after application
gasping breathing	-	0	0	0	1	+
lying on side	-	0	0	0	7	+
somnolence	-	0	0	0	13	+
abdominal position	-	0	0	0	9	+
spastic convulsion	-	0	0	0	5	+
Mortality of dams	-	0	0	0	6	+
Body weight gain [g] Mean day 0 – 20	73.0 - 101.9	98.5	95.8	90.9	66.8*	+
Body weight gain [g] corrected, day 0 – 20	-	37.6	35.3	31.0	13.7***	+
Mean food consumption (Day 0-20) [g/rat/day]	-	18.5	18.4	18.0	15.5***	+
Pregnancies	7-24	22	24	22	24	-
Necropsy findings in dams dead before end of test
reddened oesophagus	-	0	0	0	1	+
suppurative foci in lung tissue	-	0	0	0	1	+
fluid in thorax	-	0	0	0	1	+
thorax filled with serous fluid	-	0	0	0	1	+
stomach appears smaller	-	0	0	0	1	+
stomach + intestines extremely distended	-	0	0	0	1	+
reduced spleen size	-	0	0	0	1	+
gas-inflated intestines	-	0	0	0	2	+
bloody vagina	1	0	0	0	3	+
organs autolytic	-	0	0	0	1	+
Necropsy findings in dams at termination
Ovariary cysts	1	2	0	0	0	−
intestinal worms	56	3	8	7	6	-
# Skeletal retardations Statistically significant difference from controls: *p < 0.05; ** p < 0.005; *** p < 0.001

Table 2: Overview of developmental effects in the prenatal developmental toxicity study

Parameter	Controldata		30 mg/kg bw/d	100 mg/kg bw/d	300 mg/kg bw/d	Dose-response + / –
	Historical (1984-1990)	0 mg/kg bw/d
Corpora lutea[mean no./dam]	-	13.0	13.2	12.4	12.6
Implantations[mean no./dam]	8.3 - 12.5	11.4	11.3	11.2	10.6	–
Resorptions[mean no./dam]^a	0.3 - 2.3	0.6	0.8	0.6	1.8***	+
Resorptions[mean no./dam]^b		0.6	0.8	0.6	0.7	-
Foetuses[mean no./dam]	7.6 - 11.7	10.7	10.5	10.6	9.9	–
Foetus weight(mean) [g]^b	3.17 - 3.68	3.71	3.69	3.65	3.42**	+
Placenta weight[mean/dam] [g]^b	0.55 - 0.68	0.62	0.65	0.62	0.60	–
Skeletal changes [mean foetus no/dam]^b	1.44 - 3.18#	2.09	1.46	2.18	1.38	−
Malformations [mean foetus no/dam]^b	0.00 - 0.39	0.14	0.08	0.05	0.38	−
Sex ratio (m:f)^b	-	1:0.8	1:0.9	1:1.22	1:1.03	-
^awith implantations ^bwith live foetuses # Skeletal retardations Statistically significant difference from controls: *p < 0.05; ** p < 0.005; *** p < 0.001

Applicant's summary and conclusion

Conclusions:

The test substance had no effect on intrauterine development at doses causing no maternal toxicity.