Hexyl salicylate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

no data are available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study is similar to OECD 416, several currently recommended observations and parameter determinations were not performed. Notwithstanding these deficiencies, the study is acceptable (reliability: 2) for reproductive risk assessment (fertility) associated with the 3-generation study (Collins and al, 1971) and the chronic study in rat conducted by Webb and Harrisson, 1963.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Deviations:

yes

Remarks:

several deficiencies in relation to OECD Guideline 416 in terms of parameters studied

Principles of method if other than guideline:

Not relevant

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methyl salicylate

EC Number:

204-317-7

EC Name:

Methyl salicylate

Cas Number:

119-36-8

Molecular formula:

C8H8O3

IUPAC Name:

methyl salicylate

Test material form:

other: oily liquid

Details on test material:

- Name of test material: methyl salicylate (MeS)
- Substance type: no data
- Physical state: volatil (liquid)
- Analytical purity: no data
- Impurities (identity and concentrations): no data
- Lot/batch No: Blend of Lots 636, 8806, 8855 and 15349.
- Stability under test conditions: no data
- Storage condition of test material: it was stored in tightly closed, metal canisters
- Source: Dodge and Olcott, New York.

Test animals

Species:

mouse

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: no data
- Fasting period before study: no data
- Housing: no data
- Diet: no data
- Water: no data
- Acclimation period: no data


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


IN-LIFE DATES: no data

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): due to the volatility of MeS only enough diet for one week was prepared at any one time.
- Mixing appropriate amounts with (Type of food): no data
- Storage temperature of food: no data


VEHICLE: none

Details on mating procedure:

no data are available.

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

none

Duration of treatment / exposure:

30 days before the first mating and then throughout the experiment.

Frequency of treatment:

daily

Details on study schedule:

- F1 parental animals not mated until 4 weeks after selected from the F1 litters.
- Selection of parents from F1 generation when pups were 4 weeks.
- Age at mating of the mated animals in the study: 12 weeks

Doses / concentrations

Remarks:

Doses / Concentrations:
0.25% and 0.5% (2500 ppm and 5000 ppm, equivalent to 357 and 714 mg/kg bw MeS, or 324 and 628 mg/kg bw as SA)
Basis:
nominal in diet

No. of animals per sex per dose:

25/sex/dose (F0)
30/sex/dose (F1)

Control animals:

yes, concurrent no treatment

Details on study design:

no data are available

Positive control:

no data

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: no


DETAILED CLINICAL OBSERVATIONS: no

BODY WEIGHT: no

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): no

Oestrous cyclicity (parental animals):

not performed

Sperm parameters (parental animals):

not performed

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 10 pups/litter, excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in [F1 / F2 / F3] offspring:
number of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, physical or behavioural abnormalities,


GROSS EXAMINATION OF DEAD PUPS: no

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: no data
- Maternal animals: All surviving animals, after the last litter of each generation was weaned.


GROSS NECROPSY: not perfomed


HISTOPATHOLOGY / ORGAN WEIGHTS: not performed.

Postmortem examinations (offspring):

SACRIFICE
no data

GROSS NECROPSY
- Gross necropsy consisted of external examination.

HISTOPATHOLOGY / ORGAN WEIGTHS: no data

Statistics:

Analyses of variance, student-test and determination of P values.

Reproductive indices:

- Reproduction index: no. weaned 21 days/no. liveborn x 100.

Offspring viability indices:

1- Stillborn index: no. Stillborn/total born x100
2- Viability: no. alive 5 days /no. liveborn x100

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, treatment-related

Details on results (P0)

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS):
The conception rate was higher for the two groups on MeS than for the negative control groups.
The number of unsuccessful matings for the females of the negative control group was almost double that of the MeS groups .
The Reproduction indices were comparable to or greater than those of the controls.

Effect levels (P0)

1

Dose descriptor:

NOAEL

Effect level:

714 mg/kg bw/day

Basis for effect level:

other: The results of this study indicate that there were no differences in the reproductive efficiencies compared to the controls.

Remarks on result:

other: Generation: reproduction (migrated information)

2

Dose descriptor:

NOAEL

Effect level:

714 mg/kg bw/day

Basis for effect level:

other: The results of this study indicate that there were no differences in the reproductive efficiencies compared to the controls.

Remarks on result:

other: Generation: development (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:

not examined

Mortality / viability:

mortality observed, treatment-related

Body weight and weight changes:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Histopathological findings:

not examined

Details on results (F1)

VIABILITY (OFFSPRING)
- Litter size was slightly smaller in the test groups than the control.
- The neonate death rate between birth and weaning (MeS at 0.25% and 0.5%) was lower than controls.
- The negative control group experienced a larger number of stillborn than did either of the MeS.
- Viability indices of the test groups were comparable to greater than those of the controls.

GROSS PATHOLOGY (OFFSPRING)
- no abnormalities were observed in the young of the 0.25% and 0.5% MeS groups.
- All young surviving to weaning exhibited normal development in respect to body growth, appearance and behavior.

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

table 1: mouse mating performance

	% females (pregnancies/ matings)
	N (females mated twice	2/2	1/2	0/2
first generation
control	20	85,0	5,0	10,0
0,25%	22	72,3	27,3	0
0,50%	25	72,0	28,0	0
second generation
control	22	9,1	72,7	18,2
0,25%	18	16,7	66,7	16,6
0,50%	16	18,9	68,8	12,4

table 2: mean litter size - birth through weaning

	total born	live born	not killed at birth	alive 5 days	weaned 21 days
first generation
control	12,51	12,06	12,03	11,23	9,04
0,25%	10,68	10,58	10,53	10,03	9,06
0,50%	10,56	10,3	10,19	9,42	8,96
second generation
control	9,8	9,5	9,5	8,25	6,09
0,25%	11,5	11,5	11,5	11,2	7,95
0,50%	9,82	9,82	9,71	9,71	8,89

table 3: reproduction performance indices

	stillborn	viability	lactation	reproduction
first generation
control	3,65	93,1	80,5	75
0,25%	0,99	94,8	90,3	85,6
0,50%	2,42	91,4	95,2	87
second generation
control	3,06	86,8	73,8	64,1
0,25%	0	97,6	70,8	69,1
0,50%	0	98,8	91,6	90,5

Applicant's summary and conclusion

Conclusions:

Under the test condition, no adverse reproduction effects were noted in mice at dietary levels of 357 and 714 mg/kg bw/day MeS. The NOAEL of 714 mg/kg bw/day was identified.

Executive summary:

A two-generation study similar to OECD guideline 416 was conducted by Abbott and Harrisson (1978), on methylsalicylate using 25 F0 mice/sex/dose and 30 F1 mice/sex/dose. The F0 mice were fed MeS at dietary concentrations of 0.25 or 5% (equivalent to 357 or 714 mg/kg body weight) from 30 days before the first mating and throughout the entire study period. F0 and F1 mice were each mated twice. Reproduction parameters (total born, live born, live at 5 days and at weaning) and pup abnormalities were monitored. No effects on any parameter were reported at either dose level. Therefore, the NOAEL (all endpoints) was 714 mg/kg bw/day, the highest dose tested in the study.

Due to the similarity in the backbone of the molecule between methyl and hexyl salicylate and the similarity of the metabolite, salicylic acid, it is considered appropriate to use data of methyl salicylate for hexyl salicylate for reproductive toxicity. The corresponding alcohol of hexyl salicylate is expected to be less toxic compared to salicylic acid (Belsito et al., 2007).