Benzyl 4-hydroxybenzoate

Endpoint summary

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as per mentioned below

Principles of method if other than guideline:

Study of estrogenic effects on the basis of uterotrophic assay in immature SD rats treated with benzylparaben.

GLP compliance:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

female

Details on test animals or test system and environmental conditions:

Details on test animal
TEST ANIMALS
- Source: Experimental Animal Tech Co. of Weitonglihua (Beijing, China).
- Age at study initiation: Immature SD rats (Post natal day :20)
- Weight at study initiation: 61.1 ± 7.9 to 68.5 ± 6.3g
- Fasting period before study: No data available
- Housing: two or three rats per stainless steel wire-mesh cage
- Diet (e.g. ad libitum): basic diet (ad libitum)
- Water (e.g. ad libitum): sufficient drinking water (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): No data available

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

Route of administration:

other: Oral (Intragastric administration)

Vehicle:

peanut oil

Details on oral exposure:

Details on oral exposure
PREPARATION OF DOSING SOLUTIONS: No data available

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): No data available
- Concentration in vehicle: No data available
- Amount of vehicle (if gavage): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

3 days (PND 21 -24)

Frequency of treatment:

Daily

Remarks:

Doses / Concentrations:
0.16, 0.8, 4, 20, and 100 mg/kg bw/day for experiment 1 0.0064 and 0.032 mg/kg bw/ day for experiment 2
Basis:
no data

No. of animals per sex per dose:

14 /dose

Control animals:

yes

Details on study design:

No data available

Positive control:

No data available

Observations and examinations performed and frequency:

Observations and examinations performed & frequency
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: No data available
- Cage side observations checked in table [No.?] were included. No data available

DETAILED CLINICAL OBSERVATIONS: No data available
- Time schedule: No data available

BODY WEIGHT: Yes
- Time schedule for examinations: daily

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: No data available
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available

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 data available

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available
- Time schedule for examinations: No data available

OPHTHALMOSCOPIC EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available

HAEMATOLOGY: No data available
- Time schedule for collection of blood: No data available
- Anaesthetic used for blood collection: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

CLINICAL CHEMISTRY: No data available
- Time schedule for collection of blood: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

URINALYSIS: No data available
- Time schedule for collection of urine: No data available
- Metabolism cages used for collection of urine: No data available
- Animals fasted: No data available
- Parameters checked in table [No.?] were examined. No data available

NEUROBEHAVIOURAL EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available
- Battery of functions tested: sensory activity / grip strength / motor activity / other: No data available

OTHER:
Uterotrophic assay: Performed on PND 24 day, uterus of each rat was dissected. Each uterus was blotted, and the blotted weight was recorded.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Other examinations:

No data available

Statistics:

One-way analysis of variance and Fisher’s least significant difference (LSD) method.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Mortality: All rats were scarified at PND 24 day after 24 hrs of last treated diet taken. Clinical signs: No data available

Mortality:

mortality observed, treatment-related

Description (incidence):

Mortality: All rats were scarified at PND 24 day after 24 hrs of last treated diet taken. Clinical signs: No data available

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

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Uterus weight was increased of rats given 0.16 mg/kg/day or more of benzylparaben. The relative uterine weight was increased to 103%, 107%, 119%, 124%, 127%, 131%, and 136% that of rats in the control group.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Uterine weight was increased

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Dose descriptor:

other: LOED (Lowest observed Effective dose)

Effect level:

0.16 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Blotted Uterus weight

Critical effects observed:

not specified

Conclusions:

The endpoint for repeated dose toxicity test for benzylparaben (94-18-8) was found to be LOED at 0.16 mg/kg/day.

Executive summary:

Repeated dose toxicity test was performed on SD rats from PND 21 to PND 24 days were treated with benzylparaben. The chemical was given by Intragastric route dissolve in peanut oil. On 24 PND days the rats were scarified by chloroform anesthesia 24 h after the final treatment. The uterus of all rats were dissected and blotted to study the uterotrophic effect of benzylparaben. Relative uterine weight was calculated for each animal.

After experiment it was found that the relative uterine weight was increased to 103%, 107%, 119%, 124%, 127%, 131%, and 136% that of rats in the control group.

Therefore, the endpoint for repeated dose toxicity test for benzylparaben (94-18-8) was found to be LOED at 0.16 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

0.16 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Data is from peer reviewed journal

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as per mentioned below

Principles of method if other than guideline:

Subacute Study of oestrogenic activity of benzylparaben on immature mouse uterine weight.

GLP compliance:

no

Species:

mouse

Strain:

CD-1

Sex:

female

Details on test animals or test system and environmental conditions:

Details on test animal
TEST ANIMALS
- Source: Charles River, Kent, UK
- Age at study initiation: 18 days
- Weight at study initiation: No data available
- Fasting period before study: No data available
- Housing: Animals were housed in a cage of 450 mm × 280 mm × 130 mm
(length × depth × height) 7 animals per group.
- Diet (e.g. ad libitum): Standard diet in pellet form (Lillico RM1(P)), ad libitum.
- Water (e.g. ad libitum): No data available
- Acclimation period: 2 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 1 °C
- Humidity (%): 55 ± 5%
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): No data available

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

Type of coverage:

open

Vehicle:

ethanol

Details on exposure:

Details on dermal exposure
PREPARATION OF DOSING SOLUTIONS: Benzylparaben were disolved in 0.5 ml of ethanol

TEST SITE
- Area of exposure: Dorsal skin
- % coverage: No data available
- Type of wrap if used: No data available
- Time intervals for shavings or clipplings: No data available

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No data available
- Time after start of exposure: No data available

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0, 3.3, 10, 33 or 100 mg/ kg bw/day
- Concentration (if solution): No data available
- Constant volume or concentration used: yes
- For solids, paste formed: No

VEHICLE
- Justification for use and choice of vehicle (if other than water): Benzylparaben is soluble in ethanol
- Amount(s) applied (volume or weight with unit): 0, 3.3, 10, 33 or 100 mg/ kg bw/day
- Concentration (if solution): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

3 days

Frequency of treatment:

Once in a day

Remarks:

Doses / Concentrations:
3.3, 10, 33 or 100 mg of benzylparaben, 10, 25, 50, 100, 200, 1000, 5000, 25 000 or 100 000 ng of 17β-oestradiol.
Basis:
no data

No. of animals per sex per dose:

No data available

Control animals:

yes

Details on study design:

No data available

Positive control:

No data available

Observations and examinations performed and frequency:

Observations and examinations performed & frequency
CAGE SIDE OBSERVATIONS: No data available
- Time schedule: No data available
- Cage side observations checked in table [No.?] were included. No data available

DETAILED CLINICAL OBSERVATIONS: No data available
- Time schedule: No data available

DERMAL IRRITATION (if dermal study): No data available
- Time schedule for examinations: No data available

BODY WEIGHT: Yes
- Time schedule for examinations: At termination of study

FOOD CONSUMPTION: No data available
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available

FOOD EFFICIENCY: No data available
- 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 data available

WATER CONSUMPTION: No data available
- Time schedule for examinations: No data available

OPHTHALMOSCOPIC EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available

HAEMATOLOGY: No data available
- Time schedule for collection of blood: No data available
- Anaesthetic used for blood collection: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

CLINICAL CHEMISTRY: No data available
- Time schedule for collection of blood: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

URINALYSIS: No data available
- Time schedule for collection of urine: No data available
- Metabolism cages used for collection of urine: No data available
- Animals fasted: No data available
- Parameters checked in table [No.?] were examined. No data available

NEUROBEHAVIOURAL EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available
- Battery of functions tested: sensory activity / grip strength / motor activity / other: No data available

OTHER:
Organ weight: Yes
Uterus weight was weighted.

Sacrifice and pathology:

GROSS PATHOLOGY: No data available

HISTOPATHOLOGY: No data available

Other examinations:

No data available

Statistics:

The P values were calculated using a two-tailed two-sample Student’s t -test assuming unequal variance, within the MS Excel 2000 software package.

Clinical signs:

not specified

Dermal irritation:

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

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

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Details on results:

Clinical signs and mortality:No data available

Dermal Irritation: No data available

Body weight and weight gain: No effects on body weight and body weight gain were observed in all the treated mice as compared to control.

Food consumption and compound intake: No data available

Food efficiency: No data available

Water consumption and compound intake: No data available

Opthalmoscopic examination No data available

Haematology No data available

Clinical chemistry: No data available

Urinanalysis: No data available

Neurobehaviour: No data available

Organ weights When treated with 33 and 100 mg/ kg bw/day, dose-dependent significant increase in absolute and relative Uterus weight was observed as compared to control.

Gross pathology: No data available

Histopathology: No data available

Details on results
Two studies were conducted with same concentration
The results were show that benzylparaben can have weak uterotrophic activity when administered topically in ethanol to immature mice.

Dose descriptor:

LOAEL

Effect level:

33 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Effect on organ weight

Dose descriptor:

NOAEL

Effect level:

10 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No adverse effect on body weight and organ weight

Critical effects observed:

not specified

Effect of topical administration of benzylparaben on uterine weight in immature female CD1 mice

	Treatment	Uterine weight (mg)	P value vs control	Body weight (g)	Uterine wt. / body wt.	P value vs control
Study 1	Control	19.67 ± 0.83		13.22 ± 0.31	1.49 ± 0.06
	17β-E 100 ng	97.57 ± 6.03	<0.001	15.00 ± 0.66	6.51 ± 0.30	<0.001
	17β-E 1000 ng	99.71 ± 3.83	<0.001	15.92 ± 0.29	6.28 ± 0.27	<0.001
	17β-E 5000 ng	80.14 ± 3.56	<0.001	14.33 ± 0.37	5.59 ± 0.19	<0.001
	17β-E 25 000 ng	85.86 ± 4.67	<0.001	14.96 ± 0.20	5.74 ± 0.32	<0.001
	17β-E 100000 ng	89.14 ± 3.42	<0.001	14.39 ± 0.39	6.20 ± 0.19	<0.001
	BenzPara 3.3 mg	19.00 ± 1.35	0.682	13.55 ± 0.52	1.40 ± 0.07	0.329
	BenzPara 10 mg	24.14 ± 2.76	0.165	14.03 ± 0.43	1.71 ± 0.16	0.239
	BenzPara 33 mg	24.00 ± 1.84	0.064	13.16 ± 0.48	1.81 ± 0.08	0.008
	BenzPara 100 mg	31.71 ± 2.04	<0.001	13.64 ± 0.24	2.33 ± 0.16	0.002
Study 2	Control	20.75 ± 2.53		12.19 ± 0.63	1.67 ± 0.13
	17β-E 10 ng	30.57 ± 1.74	0.008	14.25 ± 0.40	2.16 ± 0.14	0.023
	17β-E 25 ng	47.71 ± 1.51	<0.001	12.62 ± 0.53	3.81 ± 0.16	<0.001
	17β-E 50 ng	84.29 ± 4.98	<0.001	15.30 ± 0.61	5.52 ± 0.30	<0.001
	17β-E 100 ng	101.29 ± 3.46	<0.001	14.98 ± 0.35	6.77 ± 0.19	<0.001
	17β-E 200 ng	101.14 ± 5.43	<0.001	15.53 ± 0.42	6.51 ± 0.26	<0.001
	BenzPara 3.3 mg	28.29 ± 4.01	0.143	13.88 ± 0.35	2.01 ± 0.26	0.259
	BenzPara 10 mg	36.71 ± 6.19	0.044	14.50 ± 0.44	2.49 ± 0.34	0.056
	BenzPara 33 mg	30.86 ± 2.24	0.010	13.80 ± 0.72	2.23 ± 0.08	0.003
	BenzPara 100 mg	24.00 ± 1.68	0.306	14.01 ± 0.48	1.71 ± 0.10	0.798

Topical application of 0.5 ml of ethanol alone (control) or containing the stated close of oestradiol (E) or benzylparaben (BenzPara). Results are given as the mean ± SEM; p values are a two-tailed two-sample t -test assuming unequal variances.

Conclusions:

NOAEL was considered to be 10 mg/kg bw/day and LOAEL was 33 mg/kg bw/day when CD1 female mice were treated with benzylparaben

Executive summary:

In a Subacute repeated dose dermal toxicity study, CD1 female mice were treated with benzylparaben in the concentration of 0, 3.3, 10, 33 or 100 mg/ kg bw/day in 0.5 ml ethanol by applying on dorsal skin. No effects on body weight and body weight gain were observed in all the treated mice as compared to control. In addition, dose-dependent significant increases in absolute and relative Uterus weight wereobserved at 33 and 100 mg/kg bw/day treated female mice in both the studies as compared to control. Therefore, NOAEL was considered to be 10 mg/kg bw/day and LOAEL was 33 mg/kg bw/day when CD1 female mice were treated with benzylparaben dermally for 3 days.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

33 mg/kg bw/day

Study duration:

subchronic

Species:

mouse

Quality of whole database:

Data is from peer reviewed journal

Additional information

Repeated dose toxicity: oral

Repeated dose toxicity test was performed on SD rats from PND 21 to PND 24 days were treated with benzylparaben. The chemical was given by Intragastric route dissolve in peanut oil. On 24 PND days the rats were scarified by chloroform anesthesia 24 h after the final treatment. The uterus of all rats were dissected and blotted to study the uterotrophic effect of benzylparaben. Relative uterine weight was calculated for each animal.

After experiment it was found that the relative uterine weight was increased to 103%, 107%, 119%, 124%, 127%, 131%, and 136% that of rats in the control group.

Therefore, the endpoint for repeated dose toxicity test for benzylparaben (94-18-8) was found to be LOED at 0.16 mg/kg/day

Repeated dose toxicity: dermal

The repeated dermal toxicity test was performed on 16 days immature mice by applying 3.3, 10, 33 or 100 mg of benzylparaben concentration in ethanol. Two separate studies were carried out. In the first topical experiment, the dose range for 17β-oestradiol was established by administration in the wide range of 100–100 000 ng. In the second topical study, 17β-oestradiol was administered in the narrower range of 10–-200 ng.

On fourth day animals were killed and body weight was measured and uterine was extracted and removed all fats, connective tissues, cervix and oviduct. Than according to two-tailed two-sample Student’st-testPvalues were calculated.

On the basis of result it was concluded that the uterine weight was increase after treatment with benzylparaben, which is demonstrates that oestrogenicity was increase by benzylparaben.

Therefore, the endpoint of repeated dose toxicity for benzylparaben (94-18-8) was found to be NOAEL at 33 mg concentration.

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

Repeated dose toxicity test was performed on SD rats from PND 21 to PND 24 days were treated with benzylparaben. The chemical was given by Intragastric route dissolve in peanut oil. On 24 PND days the rats were scarified by chloroform anesthesia 24 h after the final treatment. The uterus of all rats were dissected and blotted to study the uterotrophic effect of benzylparaben. Relative uterine weight was calculated for each animal.

After experiment it was found that the relative uterine weight was increased to 103%, 107%, 119%, 124%, 127%, 131%, and 136% that of rats in the control group.

Therefore, the endpoint for repeated dose toxicity test for benzylparaben (94-18-8) was found to be LOED at 0.16 mg/kg/day.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:

The repeated dermal toxicity test was performed on 16 days immature mice by applying 3.3, 10, 33 or 100 mg of benzylparaben concentration in ethanol. Two separate studies were carried out. In the first topical experiment, the dose range for 17β-oestradiol was established by administration in the wide range of 100–100 000 ng. In the second topical study, 17β-oestradiol was administered in the narrower range of 10–-200 ng.

On fourth day animals were killed and body weight was measured and uterine was extracted and removed all fats, connective tissues, cervix and oviduct. Than according to two-tailed two-sample Student’st-testPvalues were calculated.

On the basis of result it was concluded that the uterine weight was increase after treatment with benzylparaben, which is demonstrates that oestrogenicity was increase by benzylparaben.

Therefore, the endpoint of repeated dose toxicity for benzylparaben (94-18-8) was found to be NOAEL at 33 mg concentration.