Registration Dossier

Administrative data

Description of key information

NOAEL (oral, dog, 2 year chronic): 83 mg/kg bw/d 2-ethylhexyl salicylate adjusted
NOEAC (inhalative, rat, 28d subacute): 1155 mg/m³ 2-ethylhexyl salicylate adjusted

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This is an old study (1963), predating GLP however the protocol and results were reported in adequate detail and included hematological studies, gross pathology, and limited histopathological examinations of key organs and tissues.
Reason / purpose:
reference to same study
Qualifier:
no guideline available
Principles of method if other than guideline:
MeS was administered in dogs orally in capsule daily for a period of 2 years.
GLP compliance:
no
Limit test:
no
Species:
dog
Strain:
Beagle
Sex:
male/female
Details on test animals 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 (e.g. ad libitum): no data
- Water (e.g. ad libitum): 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
Route of administration:
oral: capsule
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:


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

VEHICLE: none
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
none
Duration of treatment / exposure:
2 years
Frequency of treatment:
daily for 6 days/week
Remarks:
Doses / Concentrations:
0, 50, 150 and 350 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
2/sex/dose
Control animals:
yes
Details on study design:
no data are available
- Dose selection rationale: the data reported in the subchronic study in dogs by the same authors (methyl salicylate/ 59 days/oral (capsule)/dogs).
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: No

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: the animals were weighed weekly

FOOD EFFICIENCY: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY:
it made at 2 weeks, 1, 3, and 6 months and 1 and 2 years

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Other examinations:
no data
Statistics:
no data available
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
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:
effects observed, treatment-related
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
- No clinical signs were observed.
- Two dogs dying of unrelated disease: one high-dose female died of infectious canine hepatitis after 33 days on the experiment.
Her replacement died of canine distemper after 19 weeks on the experiment.
BODY WEIGHT AND WEIGHT GAIN
The administration of 350 and 150 mg/kg/day retarded the growth of the dogs:
- The dogs on the highest level lost an average of 1.90 kg while the control dogs gained an average of 1.85 kg.
- The dogs on 150 mg/kg/day gained an average of only 0.5 kg.
HAEMATOLOGY
Hematological analyses at 1, 3, 6, 12 and 24 months were normal.
ORGAN WEIGHTS
Enlarged livers were seen at necropsy of the dogs on the 150 and 350 mg/kg/day levels. The heavier livers plus reduced bodyweight gain produced higher ratios of liver weight to body weight.
GROSS PATHOLOGY
At necropsy, the dogs treated at 150 and 350 mg/kg body weight/day had enlarged livers.
HISTOPATHOLOGY:
Microscopically, these livers had larger hepatic cells than those seen in the control dogs.
Fatty metamorphosis was not greater in the livers of the treated dogs than the very small amounts seen in the livers of the control dogs.
Dose descriptor:
NOAEL
Effect level:
50 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: for methyl salicylate
Dose descriptor:
NOAEL
Effect level:
83 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: read-across value for 2-ethylhexyl salicylate
Critical effects observed:
not specified
Conclusions:
Under these test conditions, animals of the 150 and 350 mg/kg groups had retarded growth and enlarged livers were observed in these animals. No effects were reported at 50 mg/kg bw/day. Based on this study, the NOAEL /oral/dogs is 50 mg/kg body weight/day for methyl salicylate. This corresponds to 83 mg/kg bw/day of 2-ethylhexyl salicylate.
Executive summary:

Webb and Hansen (1963) studied groups of two male and two female purebred beagles fed methyl salicylate in capsule form at doses of 0, 50, 150, or 350 mg/kg body weight/day, 6 days/week for 2 years.

One high-dose animal died of hepatitis apparently unrelated to methyl salicylate. Hematological analyses at 1, 3, 6, 12 and 24 months and complete necropsy examination were normal, except that dogs treated at 150 and 350 mg/kg body weight/day had enlarged livers, seen microscopically as enlarged hepatic cells. No other pathology was reported in any of the animals. Reduced body weight was reported in the 350 and 150 mg/kg body weight/day groups.

Based on this chronic oral study, the NOAEL value is 50 mg/kg body weight/day.
Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
83 mg/kg bw/day
Study duration:
chronic
Species:
dog
Quality of whole database:
The findings of three weight of evidence studies (subchronic in rat with 2-ethylhexyl salicylate, chronic in rats and dogs with methyl salicylate as read -across substance) are supported by a subacute study according to OECD 421 which also investigated 2-ethylhexylsalicylate and two further subchronic studies with rats and dogs tested with methyl salicylate.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Single concentration tested. No data on substance purity.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)
GLP compliance:
no
Species:
rat
Strain:
other: Alderley Park
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Alderley Park
- Age at study initiation: no data
- Weight at study initiation: mean 200g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Remarks on MMAD:
MMAD / GSD: Not applicable, vapour
Duration of treatment / exposure:
4 weeks
Frequency of treatment:
7 hours per day, 5 days per week
Remarks:
Doses / Concentrations:
700 mg/m3
Basis:
nominal conc.
No. of animals per sex per dose:
4
Details on study design:
not given
Positive control:
no data
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Daily

FOOD CONSUMPTION: - No data

FOOD EFFICIENCY:- No data

WATER CONSUMPTION: No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data
- Time schedule for collection of blood: No data
- Animals fasted: No data
- How many animals: No data

CLINICAL CHEMISTRY: No data

URINALYSIS: Yes
- Time schedule for collection of urine: Overnight after last exposure
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data

NEUROBEHAVIOURAL EXAMINATION: No data
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Other examinations:
none
Statistics:
no data
Clinical signs:
no effects observed
Mortality:
no mortality observed
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 examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined
Dose descriptor:
NOAEC
Effect level:
700 mg/m³ air (nominal)
Basis for effect level:
other: overall effects, no adverse effects. Values for methyl salicylate.
Dose descriptor:
NOAEC
Effect level:
1 155 mg/L air (nominal)
Basis for effect level:
other: read-across value for 2-ethylhexyl salicylate
Critical effects observed:
not specified

No toxic signs and no macroscopic or microscopic effects were seen at necropsy following exposure to a saturated atmosphere for 7 hours per day, 5 days per week for 4 weeks.

Conclusions:
Methyl salicylate showed no evidence of toxicity by inhalation when tested at an effectively saturated concentration for 7 hours per day for four weeks. The highest tested concentration of methyl salicylate of 700 mg/m³ corresponds to 1155 mg/m³ of 2-ethylhexyl salicylate.
Executive summary:

4 female Alderley Park rats weighing an average of 200 g were exposed to a dynamic atmosphere (atmosphere continuously generated and passed through the exposure chamber) containing a saturated atmosphere (700 mg/m3) of methyl salicylate for 7 hours per day, 5 days per week for 4 weeks. Food and water were available ad libitum. Animals were weighed each day, and their condition and behaviour were recorded throughout the exposure period. Urine was collected overnight after the last exposure day for biochemical testing. Gross necropsy was conducted as well as microscopic examination of organs. Methyl salicylate at 700 mg/m3 (120 ppm), the maximum achievable atmosphere, did not cause any adverse effects (Gage, 1970).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
1 155 mg/m³
Study duration:
subacute
Species:
rat

Repeated dose toxicity: inhalation - local effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Single concentration tested. No data on substance purity.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)
GLP compliance:
no
Species:
rat
Strain:
other: Alderley Park
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Alderley Park
- Age at study initiation: no data
- Weight at study initiation: mean 200g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Remarks on MMAD:
MMAD / GSD: Not applicable, vapour
Duration of treatment / exposure:
4 weeks
Frequency of treatment:
7 hours per day, 5 days per week
Remarks:
Doses / Concentrations:
700 mg/m3
Basis:
nominal conc.
No. of animals per sex per dose:
4
Details on study design:
not given
Positive control:
no data
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Daily

FOOD CONSUMPTION: - No data

FOOD EFFICIENCY:- No data

WATER CONSUMPTION: No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data
- Time schedule for collection of blood: No data
- Animals fasted: No data
- How many animals: No data

CLINICAL CHEMISTRY: No data

URINALYSIS: Yes
- Time schedule for collection of urine: Overnight after last exposure
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data

NEUROBEHAVIOURAL EXAMINATION: No data
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Other examinations:
none
Statistics:
no data
Clinical signs:
no effects observed
Mortality:
no mortality observed
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 examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined
Dose descriptor:
NOAEC
Effect level:
700 mg/m³ air (nominal)
Basis for effect level:
other: overall effects, no adverse effects. Values for methyl salicylate.
Dose descriptor:
NOAEC
Effect level:
1 155 mg/L air (nominal)
Basis for effect level:
other: read-across value for 2-ethylhexyl salicylate
Critical effects observed:
not specified

No toxic signs and no macroscopic or microscopic effects were seen at necropsy following exposure to a saturated atmosphere for 7 hours per day, 5 days per week for 4 weeks.

Conclusions:
Methyl salicylate showed no evidence of toxicity by inhalation when tested at an effectively saturated concentration for 7 hours per day for four weeks. The highest tested concentration of methyl salicylate of 700 mg/m³ corresponds to 1155 mg/m³ of 2-ethylhexyl salicylate.
Executive summary:

4 female Alderley Park rats weighing an average of 200 g were exposed to a dynamic atmosphere (atmosphere continuously generated and passed through the exposure chamber) containing a saturated atmosphere (700 mg/m3) of methyl salicylate for 7 hours per day, 5 days per week for 4 weeks. Food and water were available ad libitum. Animals were weighed each day, and their condition and behaviour were recorded throughout the exposure period. Urine was collected overnight after the last exposure day for biochemical testing. Gross necropsy was conducted as well as microscopic examination of organs. Methyl salicylate at 700 mg/m3 (120 ppm), the maximum achievable atmosphere, did not cause any adverse effects (Gage, 1970).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
1 155 mg/m³
Study duration:
subacute
Species:
rat

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Repeat dose data for oral, inhalative and dermal exposure are available on methyl salicylate as surrogate substance for 2-ethylhexyl salicylate and oral data on 2-ethylhexyl salicylate. Whereas chronic studies on methyl salicylate using rats and dogs are considered reliable and the subacute inhalative study using methyl salicylate is considered reliable too, the dermal study applying methyl salicylate to rats falls short due to a low number of animals used and high doses applied. Therefore, the dermal study with methyl salicylate was not considered reliable. The findings in the oral chronic studies with methyl salicylate in rats and dogs are well in line with those in a 90-day chronic repeat dose toxicity study with and a subacute study on 2-ethylhexyl salicylate and thus are used as key studies in a weight of evidence approach.

A read-across justification is provided as attachment to IUCLID section 13 respectively as appendix to the CSR.


Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
compliant chronic study for read-across substance methyl salicylate as worst case result supported by studies on methyl salicylate and 2-ethylhexyl salicylate, all considered reliable.

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
One study available on read-across substance methyl salicylate

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
One study available on read-across substance methyl salicylate

Justification for classification or non-classification

Based on weight of evidence using the 90-day oral feeding study with 2-ethylhexyl salicylate, supported by the results of a OECD 421 study, and the chronic data on methyl salicylate sharing the same primary metabolite (salicylic acid) with the target substance the NOAEL for this substance is set to 83 mg/kg bw/d based on chronic data in a study with beagle dogs. At this dose no relevant toxic effect were observed. Thus a classification for Specific target Organ Toxicity - Repeated Exposure (STOT RE) according to CLP (Regulation EC No 1272/2008) is not required. Also, according to DSD (Directive 67/548/EEC) a classification for chronic toxicity (R 48) is not required.