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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
fertility, other
Remarks:
Estrogenicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Data is from peer-reviewed journal

Data source

Reference
Reference Type:
publication
Title:
Potential estrogenic effect(s) of parabens at the prepubertal stage of a postnatal female rat model
Author:
Thuy T.B. Vo, Yeong-Min Yoo, Kyung-Chul Choi, Eui-Bae Jeung
Year:
2010
Bibliographic source:
Reproductive Toxicology, 29 (2010) 306–316

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: uterotrophic bioassay
Principles of method if other than guideline:
To study Estrogenic effect of isopropyl 4-hydroxybenzoate in female rats
GLP compliance:
not specified
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Isopropyl 4-hydroxybenzoate
EC Number:
224-069-3
EC Name:
Isopropyl 4-hydroxybenzoate
Cas Number:
4191-73-5
Molecular formula:
C10H12O3
IUPAC Name:
propan-2-yl 4-hydroxybenzoate
Test material form:
solid
Details on test material:
- Name of test material (as cited in study report): isopropyl 4-hydroxybenzoate
- Molecular formula : C10H12O3
- Molecular weight : 180.202 g/mole
- Smiles notation : c1(C(OC(C)C)=O)ccc(O)cc1
- InChl : 1S/C10H12O3/c1-7(2)13-10(12)8-3-5-9(11)6-4-8/h3-7,11H,1-2H3
- Substance type:Organic
- Physical state:Solid
Specific details on test material used for the study:
- Name of test material (as cited in study report): Isopropylparaben (isopropyl 4-hydroxybenzoate)
- Molecular formula (if other than submission substance): C10H12O3
- Molecular weight (if other than submission substance): 180.202 g/mole
- Substance type: Organic
- Physical state: Solid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Dea Han Biolink Co., Ltd. (Eumsung, Chungbuk, Korea).
- Age at study initiation: 21 days
- Weight at study initiation: No data available
- Fasting period before study: No data available
- Housing: Animals were housed in polycarbonate cages
- Diet (e.g. ad libitum): soy-free pellet food
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%):No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 12 h light/12 h dark

IN-LIFE DATES: From: To: No data available

Administration / exposure

Route of administration:
oral: gavage
Type of inhalation exposure (if applicable):
not specified
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: isopropylparaben was administrated in Corn oil

DIET PREPARATION
- Rate of preparation of diet (frequency): No data available
- Mixing appropriate amounts with (Type of food): No data available
- Storage temperature of food: No data available

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil
- Concentration in vehicle:0, 62.5, 250 and1000 mg/kg BW/day
- Amount of vehicle (if gavage): 5 ml/kg BW/day
- Lot/batch no. (if required): No data available
- Purity: No data available
Details on mating procedure:
- M/F ratio per cage: 1:1
- Length of cohabitation: No data available
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy: Vaginal plugs and/or sperm presence in the vaginal smear was taken as gestation day 0 (GD 0).
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
20 days
Frequency of treatment:
Daily
Details on study schedule:
No data available
Doses / concentrations
Remarks:
0, 62.5, 250 and1000 mg/kg BW/day
No. of animals per sex per dose:
Total: 50
0 mg/kg BW/day: 10 Female
62.5 mg/kg BW/day: 10 Female
250 mg/kg BW/day: 10 Female
1000 mg/kg BW/day: 10 Female
EE (mg/kg BW/day) (Positive control) : 10 Female
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: No data available
- Rationale for animal assignment (if not random): prepubertal female rats were selected.
- Other:doses were adjusted daily for weight changes.
Positive control:
Ethinylestradiol (EE) (1 mg/kg BW/day) were used as positive control.

Examinations

Parental animals: Observations and examinations:
No data available
Oestrous cyclicity (parental animals):
proestrous, estrous, metestrous, and diestrous, were determined
Sperm parameters (parental animals):
No data available
Litter observations:
No data available
Postmortem examinations (parental animals):
Changes in body weight, clinical signs and/or abnormal behavior, Clinical chemistry, organ weight and Histopathology were examined.
Postmortem examinations (offspring):
No data available
Statistics:
Data for the vaginal opening (VO) day, bodyweight, and organ weight of the rats were statistically evaluated by one-way ANOVA. Significant differences between treatment groups and the respective controls were tested using Tukey’s multiple regression test at p < 0.05. The variable category of the incidence data in the ovarian changes was used as the outcome. The occurrence of differences in histopathological changes, i.e., decrease of corpora lutea, increase in the number of cystic follicles or decrease of corpora lutea, increase in the number of cystic follicles, was verified using Fisher’s exact probability test between VE and EE, or paraben groups. The rejection value for the null hypothesis was p≤0.05.
Reproductive indices:
No data available
Offspring viability indices:
No data available

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not specified
Mortality:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
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 specified
Organ weight findings including organ / body weight ratios:
not specified
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)

Dose descriptor:
other: not specified
Based on:
not specified
Sex:
not specified
Basis for effect level:
other: not specified
Remarks on result:
other: not specified

Target system / organ toxicity (P0)

Critical effects observed:
not specified
System:
other: not specified
Organ:
not specified
Treatment related:
not specified
Dose response relationship:
not specified
Relevant for humans:
not specified

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not specified
Mortality:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
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 specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not specified
Other effects:
not specified
Details on results:
not specified

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
not specified

Details on results (P1)

not specified

Effect levels (P1)

Dose descriptor:
other: not specified
Based on:
not specified
Sex:
not specified
Basis for effect level:
other: not specified
Remarks on result:
other: not specified

Target system / organ toxicity (P1)

Critical effects observed:
not specified
System:
other: not specified
Organ:
not specified
Treatment related:
not specified
Dose response relationship:
not specified
Relevant for humans:
not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not specified
Mortality / viability:
not specified
Body weight and weight changes:
effects observed, non-treatment-related
Food consumption and compound intake (if feeding study):
not specified
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:
effects observed, treatment-related
Urinalysis findings:
not specified
Sexual maturation:
effects observed, treatment-related
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
not specified
Histopathological findings:
effects observed, treatment-related
Other effects:
effects observed, treatment-related

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not specified

Details on results (F1)

Body weight: No significant change in body weight was observed in treated rat as compared to control.

Clinical chemistry:
When treated with 250 mg/kg bw, significant decrease in tetra-iodothyronine (T4) level were observed as compared to control.
When treated with 1000 mg/kg bw, significant decrease in Estradiol level were observed as compared to control.

Sexual maturation:
Vaginal opening (VO) day: When treated with 250 and 1000 mg/kg bw, significant delay in Vaginal opening (VO) day were observed as compared to control.
Estrous cycles: When treated with 1000 mg/kg bw, significant decrease in n the number of 4-day estrous cycles were observed as compared to control.

Organ weight:
When treated with 1000 mg/kg bw, significant decrease in ovary and Kidney weight were observed as compared to control.

Histopathology:
When treated with 1000 mg/kg bw, decrease of corpora lutea and increase number of cystic follicles, myometrial hypertrophy of uterus, were observed as compared to control.

Other effect:
Estrogen receptor competitive binding assay: 50% inhibition of ligand binding (IC50) was observed in treated female rats.

Effect levels (F1)

Dose descriptor:
NOAEL
Generation:
F1
Effect level:
62.5 mg/kg bw/day
Based on:
test mat.
Sex:
female
Basis for effect level:
sexual maturation
body weight and weight gain
clinical biochemistry
organ weights and organ / body weight ratios
histopathology: non-neoplastic
other: No effect
Remarks on result:
other: non toxic

Target system / organ toxicity (F1)

Critical effects observed:
not specified
System:
other: not specified
Organ:
not specified
Treatment related:
not specified
Dose response relationship:
not specified
Relevant for humans:
not specified

Results: F2 generation

General toxicity (F2)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not specified
Mortality / viability:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
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
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified
Other effects:
not specified

Developmental neurotoxicity (F2)

Behaviour (functional findings):
not specified

Developmental immunotoxicity (F2)

Developmental immunotoxicity:
not specified

Effect levels (F2)

Dose descriptor:
other: not specified
Based on:
not specified
Sex:
not specified
Basis for effect level:
other: not specified
Remarks on result:
other: not specified

Target system / organ toxicity (F2)

Critical effects observed:
not specified
System:
other: not specified
Organ:
not specified
Treatment related:
not specified
Dose response relationship:
not specified
Relevant for humans:
not specified

Overall reproductive toxicity

Reproductive effects observed:
not specified
Treatment related:
not specified
Relation to other toxic effects:
not specified
Dose response relationship:
not specified
Relevant for humans:
not specified

Any other information on results incl. tables

Measurement of vaginal opening (VO) day.

Chemical

Dose (mg/kg BW/day)

 

62.5

250

1000

VE

 

33.6 ± 3.23

 

Isopropylparaben

35.2 ± 3.26

36.2 ± 1.03a

36.7 ± 0.71a

a p < 0.05 compared with VE.

Effects of parabens on body weight and organ weight (uterine, pituitary, ovary, adrenal gland, thyroid gland, kidney, liver) in peripubertal female rats.

Groups

Body weight (g)

Uterus weight

(mg/g BW)

Pituitary

weight (mg/g

BW)

Ovary weight

(mg/g BW)

Thyroid weight

(mg/g BW)

Kidney weight

(mg/g BW)

Adrenal weight

(mg/g BW)

Liver weight

(mg/g BW)

VE

118.69 ± 6.4

1.29 ± 0.11

0.043 ± 0.008

0.51 ± 0.06

0.86 ± 0.07

8.31 ± 0.57

0.27 ± 0.01

42.90 ± 2.17

EE (mg/kg BW/day)

61.56 ± 4.85b

3.40 ± 0.30b

0.077 ± 0.012b

0.45 ± 0.05

1.23 ± 0.1b

9.94 ± 0.63b

0.38 ± 0.03b

52.38 ± 2.77b

Isopropylparaben (mg/kg BW/day)

 

 

 

 

 

 

 

 

62.5

110.67 ± 7.85

1.19 ± 0.30

0.045 ± 0.005

0.41 ± 0.06

0.85 ± 0.07

8.04 ± 0.44

0.29 ± 0.03

41.22 ± 3.00

250

113.85 ± 5.87

1.15 ± 0.44

0.047 ± 0.009

0.04 ± 0.07

0.82 ± 0.06

7.66 ± 0.47

0.27 ± 0.02

40.58 ± 3.19

1000

102.45 ± 4.38

0.87 ± 0.22

0.044 ± 0.003

0.32 ± 0.05a

0.88 ± 0.08

7.25 ± 0.35a

0.3 ± 0.02

41.75 ± 2.04

Mean±SD; n = 10 prepubertal female rats/group.

ap < 0.05 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

bp < 0.01 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

Histopathological effects of parabens on the ovaries and uteri of peripubertal female rats.

Groups

Ovary

Uterus

 

Decrease of corpora lutea,

increase in the number of

cystic follicles (n = 10), n (%)

Not decrease of corpora lutea,

increase in the number of

cystic follicles (n = 10), n (%)

P-value*

Thickness of

morphometric

measurement (m)

VE

0 (0%)

10 (100%)

 

125.64 ± 4.44

EE (mg/kg BW/day)

7 (70%)

3 (30%)

0.0015

253.85 ± 27.74b

Isopropylparaben (mg/kg BW/day)

 

 

 

 

62.5

2 (20%)

8 (80%)

0.2368

141.03 ± 8.88

250

3 (30%)

7 (70%)

0.1052

189.74 ± 32.03

1000

5 (50%)

5 (50%)

0.0162

212.82 ± 4.44a

Mean±SD; 10 rats were examined for each dose.

* Fisher’s exact probability test for category variables (categorized histopathological changes: decrease of corpora lutea, increase in the number of cystic follicles or not decrease of corpora lutea, increase in the number of cystic follicles on the vehicle (VE) and EE or paraben exposure groups) respectively. There rejection value for the null hypothesis was p≤0.05.

ap < 0.05 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

bp < 0.01 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

Effects of parabens on circulating estradiol, prolactin, and T4 levels in peripubertal female rats.

Groups

Estradiol (pg/ml)

Prolactin (ng/ml)

T4 (ng/ml)

VE

47.07 ± 14.72

9.81 ± 3.12

3.00 ± 0.32

EE (mg/kg BW/day)

55.37 ± 14.77

238.93 ± 35.00b

2.73 ± 0.50

Isopropylparaben (mg/kg BW/day)

 

 

 

62.5

30.53 ± 15.91

45.10 ± 13.12

2.70 ± 0.39

250

25.20 ± 6.05

49.76 ± 58.31

1.73 ± 0.34b

1000

16.23 ± 6.86a

24.12 ± 6.46

3.06 ± 0.19

Mean±SD; n = 10 prepubertal female rats/group.

ap < 0.05 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

bp < 0.01 vs. vehicle (VE) (Tukey’s multiple regression test at p < 0.05).

Relative binding affinities of various parabens to ERαand ERβ.

Compound

ERα

ERβ

 

IC50a

RBAb

IC50a

RBAb

17βEstradiol

2.99×10−9M

 

100

 

3.03×10−9M

 

100

Isopropylparaben

1.52×10−5M

 

0.019

 

1.69×10−5M

0.017

Each value was the mean of triplicate determinations in more than four experiments.

aIC50 is the concentration of the paraben compound that inhibits binding of Fluormone ES2 to ER by 50%.

bRBA was calculated by the equation: (IC50 of 17-estradiol/IC50 of parabens)×100.

Applicant's summary and conclusion

Conclusions:
NOAEL was considered to be 62.5 mg/kg bw when Sprague-Dawley female rats were treated with isopropyl 4-hydroxybenzoate orally by gavage for 20 days.
Executive summary:

In a reproductive estrogenicity study, Sprague-Dawley female rats were treated with isopropyl 4-hydroxybenzoate in the concentration of 0, 62.5, 250 and 1000 mg/kg bw from postnatal day 21–40 orally by gavage in corn oil and Ethinylestradiol (1 mg/kg BW/day) was used as a positive control. No significant change in body weight was observed in treated rat as compared to control. Significant decrease in tetra-iodothyronine (T4) level at 250 mg/kg bw and significant decrease in Estradiol level at 1000 mg/kg bw, were observed as compared to control. Similarly, significant delay in Vaginal opening (VO) day were observed at 250 and 1000 mg/kg bw as compared to control. Significant decrease in n the number of 4-day estrous cycles were observed at 1000 mg/kg bw as compared to control. In addition, significant decrease in ovary and Kidney weight were observed at 1000 mg/kg bw as compared to control. Decrease of corpora lutea and increase number of cystic follicles, myometrial hypertrophy of uterus, were observed at 1000 mg/kg bw as compared to control. 50% inhibition of ligand binding (IC50) was observed in treated female rats. Therefore, NOAEL was considered to be 62.5 mg/kg bw when Sprague-Dawley female rats were treated with isopropyl 4-hydroxybenzoate orally by gavage for 20 days.