Methyl phenylacetate

Endpoint summary

Description of key information

Acute oral toxicity: 

The acute oral toxicity dose (LD50) was considered based on different studies conducted on rats for the test chemical. The LD50 value was considered to be >2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral toxicity.

Acute Inhalation Toxicity:

The given test chemical is used as a fragrance ingredient. The inhalation exposure for test chemical is reported to be 0.00014 mg/kg/day or 0.010 mg/day (Api et al., 2018; IFRA, 2015). This is 95th percentile calculated exposure derived from concentration survey data in the Creme RIFM aggregate exposure model. Also, the vapour pressure of the chemical is low (0.127 mmHg). Hence this end point is considered for waiver.

 

Acute Dermal toxicity:

The acute dermal toxicity dose (LD50) was considered based on different studies conducted on rats and rabbits for the test chemical. The study concluded that LD50 value is >2000 mg/kg bw, for acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Principles of method if other than guideline:

The aim of this study was to assess the toxicity potential of the given test chemical after single oral administration in rats.

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:In-house animals, bred at Animal House, sa-FORD.
- Age at study initiation: 8- 10 weeks at the time of dosing.
- Health Status :Healthy young adult animals were used for the study. Females were nulliparous and non pregnant.
- Weight at study initiation: Minimum: 144 g and Maximum: 169 g (Individual body weights were within ± 5 % prior to treatment after overnight
fasting)
- Fasting period: The animals were fasted for minimum 16-18 hours prior to dosing and for 4 hours post dosing.
- Housing: The animals were housed individually in polycarbonate cages.
- Bedding:All cages were provided with corn cobs SPAR – 26 /2014 and SPAR – 27 /2014.
- Room Sanitation: The experimental room floor and work tops were swept and mopped with disinfectant solution every day.
- Cages and water bottle:All the cages and water bottles were changed at least twice every week.
- Diet (e.g. ad libitum):All animals were provided conventional laboratory rodent diet (Nutrivet Life Sciences, Pune) ad libitum. Batch No.: 400010.
- Water (e.g. ad libitum): Aqua guard filtered tap water was provided ad libitum via drinking bottles.
- Acclimation period:Animal nos. 1-3 were acclimatized for 7 days and 4-6 for 9 days, prior to administration of the test item.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):Minimum: 19.60 °C and Maximum: 21.40 °C.
- Humidity (%):Minimum: 47.40 % and Maximum: 58.60%.
- Air changes (per hr):More than 12 changes per hour.
- Photoperiod (hrs dark / hrs light):12:12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 2000 mg/kg bw
- Amount of vehicle (if gavage):10 ml/kg bw

DOSAGE PREPARATION (if unusual): Added slowly vehicle in the test item and mixed well. Transfrred the formulation to the measuring cylinder and made the volume upto desired quantity of 10 ml. the dosing solution was prepared freshly,shortly prior to dose administration.

Doses:

G1 = 2000 mg/kg
G2 = 2000 mg/kg

No. of animals per sex per dose:

6 female rats

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical Observation - After test item administration, individual animals were frequently observed at 30 minutes, 1, 2, 3 and 4 hours post dosing on day 0 (day of dosing). Subsequently, all surviving animals were observed once a day during the 14 day observation period.
Mortality - All surviving animals were observed twice daily (morning and evening) for morbidity and mortality, throughout the acclimatization and study period.
Body weight - All surviving rats were weighed on days 0 (prior to dosing), 7 and 14.
- Necropsy of survivors performed: yes, at the end of 14 day observation period, all the survived rats were euthanised by overdose of CO2. All the animals were observed for external and internal gross pathology.

Statistics:

not specified

Preliminary study:

not specified

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality was observed

Mortality:

No mortality was observed in the animals treated with 2000 mg/kg dose throught out the 14 days observation period.

Clinical signs:

other: At 2000 mg/kg, all the animals were normal throughout the experimental period.

Gross pathology:

No external and internal gross pathological changes were seen in all the six animals treated with 2000 mg/kg body weight during terminal sacrifice.

Other findings:

not specified

Table 1: Individual Animal Body Weight (g) andBody Weight Changes(%)

 Sex: Female

Animal No.	Group/ Dose (mg/kg)	Body Weight (gram)			Body Weight Change (%)
		Day 0	Day 7	Day 14	Day 0-7	Day 0-14
1	G1/ 2000	169	205	212	21.30	25.44
2		156	181	197	16.03	26.28
3		158	192	214	21.52	35.44
4		144	169	178	17.36	23.61
5		157	199	205	26.75	30.57
6		149	175	184	17.45	23.49

Table 2: Summary of Animal Body Weight (g) and Body Weight Changes (%)

 

Sex: Female

Group/ Dose (mg/kg)		Rats Body Weight (g)			Body Weight Changes (%)
		Day 0	Day 7	Day 14	0-7	0-14
G1/ 2000	Mean	155.50	186.83	198.33	20.07	27.47
	SD	8.55	14.12	14.81	3.97	4.68
	n	6	6	6	6	6

Keys:SD = Standard Deviation, n = Number of Animals

Table 3: Individual Animal Clinical Signs and Symptoms

 

Sex: Female

Animal No.	Group/ Dose (mg/kg)	Hours (Day 0)
		1/2	1	2	3	4
1	G1/ 2000	1	1	1	1	1
2		1	1	1	1	1
3		1	1	1	1	1
4		1	1	1	1	1
5		1	1	1	1	1
6		1	1	1	1	1

 

Animal No.		Group/ Dose (mg/kg)		Days post dosing
			1		2		3		4		5		6		7		8		9		10		11		12		13		14
1		G1/ 2000		1		1		1		1		1		1		1		1		1		1		1		1		1		1
2			1		1		1		1		1		1		1		1		1		1		1		1		1		1
3			1		1		1		1		1		1		1		1		1		1		1		1		1		1
4			1		1		1		1		1		1		1		1		1		1		1		1		1		1
5			1		1		1		1		1		1		1		1		1		1		1		1		1		1
6			1		1		1		1		1		1		1		1		1		1		1		1		1		1

Keys:1 = Normal

Interpretation of results:

other: not classified

Conclusions:

Under the conditions of this; acute oral toxicity dose was considered to be >2000 mg/kg bw, when female rats were treated with the given test chemical via oral gavage route.

Executive summary:

Acute oral toxicity study was conducted for the given test chemical as per OECD No. 423 (Acute Oral toxicity - Acute Toxic Class Method) in female Wistar rats.

Six female Wistar rats were selected for acute oral toxicity study. The animals were fasted for minimum 16-18 hours prior to dosing and for 4 hours post dosing, food  was  withheld but drinking water provided ad libitum. The time intervals between dosing were determined by the onset, duration and severity of toxic signs.

Three rats of first group were dosed with starting dose of 2000 mg/kg body weight and the animals did not show any mortality so another three animals of the same group were dosed with 2000 mg/kg body weight and no mortality was observed. Hence, further dosing was stopped.

Body weights were re­corded on day 0 (prior to dosing) 7 and 14. Mean body weight of all the animals treated with 2000 mg/kg body weight was observed with gain on day 7 and 14, as compared to day 0. At 2000 mg/kg, all the animals were normal throughout the experimental period. No external and internal gross pathological changes were seen in all the six animals treated with 2000 mg/kg body weight during terminal sacrifice.

Under the conditions of this; acute oral toxicity dose was considered to be >2000 mg/kg bw, when female rats were treated with the given test chemical via oral gavage route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Data is Klimisch 1 and from study report.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Quality of whole database:

Waiver

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The objective of the study was to assess the dermal toxicity of the given test chemical after single dose application by dermal route in rats.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:In-House Bred at Sa-Ford, Animal Facility.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Healthy young adult animals were used for the study.
- Weight (Prior to Treatment):Male:Minimum: 256 g and Maximum: 290 g ,Female:Minimum: 232 g and Maximum: 256 g
- Housing: The animals were housed individually in polycarbonate cages.
- Bedding : All cages were provided with corn cobs (Sparconn Life Sciences Bangalore) Batch No.: SPAR – 26/2014 and SPAR – 27/2014
- Room Sanitation : The experimental room floor and work tops were swept and mopped with disinfectant solution every day.
- Cages and water bottle : All the cages and water bottles were changed at least twice every week.
- Diet (e.g. ad libitum):All animals were provided conventional laboratory rodent diet (Nutrivet Life Sciences, Pune) ad libitum. Batch No 400010.
- Water (e.g. ad libitum):Aqua guard filtered tap water was provided ad libitum via drinking bottles.
- Acclimation period: All animals were acclimatized to the test conditions for 7 days prior to administration of the test item.
- Randomization : Animals were selected manually. No computer generated randomization program was used.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):Minimum: 19.70 °C and Maximum: 21.40 °C
- Humidity (%):Minimum: 47.40% and Maximum: 58.60%
- Air changes (per hr):More than 12 changes per hour
- Photoperiod (hrs dark / hrs light):12:12

Type of coverage:

occlusive

Vehicle:

other: distilled water

Details on dermal exposure:

TEST SITE
- Area of exposure:The test item was applied uniformly over clipped dorsal area of rat skin.
- % coverage:Approximately 10% body surface area of rat.
- Type of wrap if used: The porous gauze dressing and non-irritating tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done):The residual test item was removed by using distilled water.
- Time after start of exposure:24-hour.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):A limit dose of 2000 mg/ kg body weight of test item was applied.
- Constant volume or concentration used: yes

Duration of exposure:

24 hrs

Doses:

2000 mg/kg body weight.

No. of animals per sex per dose:

10 (Five per sex)

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical Observation - After test item administration, individual animals were frequently observed at 1, 2, 3 and 4 hours post dosing on day 0 (day of dosing). Subsequently, all animals were observed once a day during the 14 day observation period.
Mortality - Animals were observed twice daily for any mortality during the experimental period.
Body weight - All rats were weighed on days 0 (prior to dosing), 7 and 14.
Local Signs/Skin Reactions - All animals were observed once daily during days 1-14 (in common with clinical signs).
- Necropsy of survivors performed: At the end of 14 day observation period, all the surviving rats were euthanised by overdose of CO2 and subjected to gross pathology examination, for external and internal observations.

Statistics:

No statistical analysis was performed since the study was terminated with limit test.

Preliminary study:

not specified

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality was observed

Mortality:

No mortality was observed at limit dose of 2000 mg/kg body weight during the 14 day observation period

Clinical signs:

other: At 2000 mg/kg, all the animals were observed normal throughout the experimental period

Gross pathology:

The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality

Other findings:

not specified

Table 1: Individual Animal Body Weight (g) andBody Weight Changes(%)

 

Dose:2000 mg/ kg bodyweight                                                                            Density:1.05513

Animal No.	Sex	Dose Volume* (ml)	Body Weight (gram)			Body Weight Change (%)
			Day 0	Day 7	Day 14	Day 0-7	Day 0-14
1	Male	0.55	290	298	305	2.76	5.17
2		0.52	275	286	310	4.00	12.73
3		0.50	265	273	294	3.02	10.94
4		0.49	257	268	283	4.28	10.12
5		0.49	256	261	265	1.95	3.52
6	Female	0.46	242	245	249	1.24	2.89
7		0.45	235	237	239	0.85	1.70
8		0.44	232	236	239	1.72	3.02
9		0.46	244	246	247	0.82	1.23
10		0.49	256	257	261	0.39	1.95

Keys: * = based on the test item density and day 0 body weight

Table 2: Individual Animal Clinical Signs and Symptoms

 

Dose:2000 mg/kg body weight

Animal No.	Sex	Hour(s) - Day 0				Day
		1	2	3	4	1	2	3	4	5	6	7
1	Male	1	1	1	1	1	1	1	1	1	1	1
2		1	1	1	1	1	1	1	1	1	1	1
3		1	1	1	1	1	1	1	1	1	1	1
4		1	1	1	1	1	1	1	1	1	1	1
5		1	1	1	1	1	1	1	1	1	1	1
6	Female	1	1	1	1	1	1	1	1	1	1	1
7		1	1	1	1	1	1	1	1	1	1	1
8		1	1	1	1	1	1	1	1	1	1	1
9		1	1	1	1	1	1	1	1	1	1	1
10		1	1	1	1	1	1	1	1	1	1	1

 

Animal No.	Sex	Day
		8	9	10	11	12	13	14
1	Male	1	1	1	1	1	1	1
2		1	1	1	1	1	1	1
3		1	1	1	1	1	1	1
4		1	1	1	1	1	1	1
5		1	1	1	1	1	1	1
6	Female	1	1	1	1	1	1	1
7		1	1	1	1	1	1	1
8		1	1	1	1	1	1	1
9		1	1	1	1	1	1	1
10		1	1	1	1	1	1	1

Key: 1 = Normal

Table 3: Individual Animal Mortality Record

 

Dose:2000 mg/kg body weight

Animal No.	Sex	Days of Observation (0 to 14)
		Morning Observations	Evening Observations
1	Male	No mortality and morbidity	No mortality and morbidity
2		No mortality and morbidity	No mortality and morbidity
3		No mortality and morbidity	No mortality and morbidity
4		No mortality and morbidity	No mortality and morbidity
5		No mortality and morbidity	No mortality and morbidity
6	Female	No mortality and morbidity	No mortality and morbidity
7		No mortality and morbidity	No mortality and morbidity
8		No mortality and morbidity	No mortality and morbidity
9		No mortality and morbidity	No mortality and morbidity
10		No mortality and morbidity	No mortality and morbidity

Interpretation of results:

other: Not classified

Conclusions:

The LD50 value was considered to be >2000 mg/kg bw, when male and female wistar rats were occlusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

Executive summary:

Acute dermal toxicity study was conducted by using the given test chemical as per OECD No. 402 in Wistar rats.

Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Rats free from injury and irritation of skin were selected for the study. Approximately, twenty four hours prior to dermal application of test item, greater than 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight based on the test item density (1.05513) and latest body weight was applied by single dermal application and observed for 14 days after treatment.

On test day 0, calculated volume of test item was applied directly on the intact skin of clipped area of rats; the porous gauze dressing was put on to the intact skin of clipped area. This porous gauze dressing was covered with a non-irritating tape. After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water. The skin reactions were assessed.

The animals were observed daily for mortality and clinical signs, during the acclimatization period and post dosing till the termination. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically.

No mortality was observed in any animal till the end of the experimental period. At 2000 mg/kg, all the animals were observed normal throughout the experimental period. Mean body weight was observed with gain on day 7 and 14 of male and female animals, as compared to day 0. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Hence, the LD50 value was considered to be >2000 mg/kg bw, when male and female wistar rats were occlusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Data is Klimisch 1 and from study report.

Additional information

Acute oral toxicity:

In different studies, the given test chemical has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats for test chemical. The studies are summarized as below –

 

The reported study was designed and conducted to determine the acute oral toxicity profile of the given test chemical as per OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method) in female Wistar rats.

Six female Wistar rats were selected for acute oral toxicity study. The animals were fasted for minimum 16-18 hours prior to dosing and for 4 hours post dosing, food  was  withheld but drinking water provided ad libitum. The time intervals between dosing were determined by the onset, duration and severity of toxic signs.

Three rats of first group were dosed with starting dose of 2000 mg/kg body weight and the animals did not show any mortality so another three animals of the same group were dosed with 2000 mg/kg body weight and no mortality was observed. Hence, further dosing was stopped.

Body weights were re­corded on day 0 (prior to dosing) 7 and 14. Mean body weight of all the animals treated with 2000 mg/kg body weight was observed with gain on day 7 and 14, as compared to day 0. At 2000 mg/kg, all the animals were normal throughout the experimental period. No external and internal gross pathological changes were seen in all the six animals treated with 2000 mg/kg body weight during terminal sacrifice.

Under the conditions of this; acute oral toxicity dose was considered to be >2000 mg/kg bw, when female rats were treated with the given test chemical via oral gavage route.

 

The above study report is supported with another study mentioned in different publications, handbooks and authoritative databases for the given test chemical. The acute oral toxicity study was conducted in rats at the dose concentration range of 1670-3430 mg/kg bw. Animals were observed for mortality. 50% mortality was observed at 2550 mg/kg bw in treated animals. Hence, the LD50 value was considered to be 2550 mg/kg bw, with 95% confidence limits of 1670-3430 mg/kg bw, when rats was treated with the given test chemical via oral route.

 

These studies are further supported with the data available in handbook for the test chemical. The acute oral toxicity study was conducted in rats at the dose concentration of 2600 mg/kg bw. Animals were observed for mortality. 50% mortality was observed at 2600 mg/kg bw in treated animals. Hence, the LD50 value was considered to be 2600 mg/kg bw, when rats was treated with the given test chemical via oral route.

 

Thus, based on the above summarised studies on test chemical, it can be concluded that LD50 value is >2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral toxicity.

 

Acute Inhalation Toxicity:

The given test chemical is used as a fragrance ingredient. The inhalation exposure for test chemical is reported to be 0.00014 mg/kg/day or 0.010 mg/day (Api et al., 2018; IFRA, 2015). This is 95th percentile calculated exposure derived from concentration survey data in the Creme RIFM aggregate exposure model. Also, the vapour pressure of the chemical is low (0.127 mmHg). Hence this end point is considered for waiver.

 

Acute Dermal Toxicity:

In different studies, the given test chemical has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats and rabbits for test chemical. The studies are summarized as below -

 

The reported study was designed and conducted to determine the acute dermal toxicity profile of the given test chemical as per OECD Guideline 402 (Acute Dermal Toxicity) in Wistar rats.

Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Rats free from injury and irritation of skin were selected for the study. Approximately, twenty four hours prior to dermal application of test item, greater than 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight based on the test item density (1.05513) and latest body weight was applied by single dermal application and observed for 14 days after treatment.

On test day 0, calculated volume of test item was applied directly on the intact skin of clipped area of rats; the porous gauze dressing was put on to the intact skin of clipped area. This porous gauze dressing was covered with a non-irritating tape. After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water. The skin reactions were assessed.

The animals were observed daily for mortality and clinical signs, during the acclimatization period and post dosing till the termination. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically.

No mortality was observed in any animal till the end of the experimental period. At 2000 mg/kg, all the animals were observed normal throughout the experimental period. Mean body weight was observed with gain on day 7 and 14 of male and female animals, as compared to day 0. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Hence, the LD50 value was considered to be >2000 mg/kg bw, when male and female wistar rats were occlusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

 

Another study mentioned in publication, handbooks and authoritative databases was carried out to determine the acute dermal toxicity dose by using the given test chemical in rabbits at the dose concentration range of 1670-3430 mg/kg bw. Animals were observed for mortality. 50% mortality was observed at 2400 mg/kg bw in treated animals. Hence, the value was considered to be 2400 mg/kg bw, with 95% confidence limits of 150-4700 mg/kg bw, when rabbits was treated with the given test chemical by dermal application.

 

Thus, based on the above summarised studies for test chemical, it can be concluded that LD50 value is >2000 mg/kg bw, for acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

 

Justification for classification or non-classification

Based on the above studies for the test chemical, it can be concluded that LD50 value is >2000 mg/kg bw, for acute oral and acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral and acute dermal toxicity. For acute inhalation toxicity wavier was added so, not possible to classify.