2-phenoxyethyl isobutyrate

Endpoint summary

Description of key information

Oral: LD50 between 2060 and 5015 mg/kg bw, male/female mice, Smith (1979).

Dermal: LD50 > 2000 mg/kg bw, male/female rat,  OECD 402, EU Method B.3, Sanders (2012).

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

Study period:

09 July 1979 to 07 September 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: A non-GLP study performed in accordance with generally accepted scientific principles with incomplete reporting and methodological deficiencies which do not affect the quality of the relevant results.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Four to five week old white mice were dosed with 3 dose levels using graded volumes of the test material via gavage. Animals were observed for up to 7 days after exposure. All animals dying were autopsied and those surviving until termination were sacrificed and examined post mortem after 7 days.

GLP compliance:

no

Test type:

other: Oral intubation at 3 dose levels

Limit test:

no

Species:

mouse

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 4-5 weeks.
- Fasting period before study: 4 hours.
- Housing: animals were placed in individual cages.
- Diet: commercial pelleted diet ad libitum.
- Water: ad libitum.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

The animals were placed in individual cages, fasted for four hours and then the animals were individually weighed and inbtubated with the appropriate volumes of the test material. Each animal on one dose level received the same amount per kg body weight.

Doses:

2, 5 and 10 mL/kg bw.

No. of animals per sex per dose:

One male and one female were dosed with 2 and 10 mL/kg bw of the test material.
Three males and three females were dosed with 5 mL/kg bw of the test material.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days.
- Frequency of weighing: Animals were weighed prior to dosing, and then again prior to sacrifice.
- Necropsy of survivors performed: yes.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 - < 5 mL/kg bw

Based on:

act. ingr.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 060 - 5 150 mg/kg bw

Based on:

act. ingr.

Mortality:

Mortalities can be seen in Table 1.

Clinical signs:

other: Mice dosed at all three dose levels were drowsy, showing signs of stress, and exhibiting laboured breathing within 30 minutes. Within 1 hour after treatment mice were also hypothermic. Within 2 hours of treatment the mice dosed at 10 mL/kg were comatose a

Gross pathology:

Autopsy of the animals that died revealed distension of the stomach due to the presence of orange/yellow fluid. The stomach and intestines were very pale and the ileum was irritated and haemorrhaging present in some animals. These mice also exhibited pale livers and kidneys. The surviving females appeared normal at autopsy.

Table 1. Mortalities

Dose Level ml/kg bw	No. of Dead Mice/No. of Animals Treated
10.0	2/2
5.0	4/6
2.0	1/2

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test the approximate LD50 of the test material was determined to be between 2.0 and 5.0 mL/kg bodyweight.

Executive summary:

The acute oral toxicity of the test material was determined by gavage in 4-5 week old white mice at 3 dose levels using graded volumes of the test material, 10.0, 5.0 and 2.0 mL/kg bw. Animals were observed for up to 7 days after exposure. All animals dying were autopsied and those surviving until termination were sacrifices and examined post mortem after 7 days. Two mice were dosed at the high and low dose levels and six for the middle dose level. Equal numbers of males and females were used.

During the study both mice dosed with 10 mL/kg, four of the six mice dosed with 5 mL/kg and the one male mouse dosed at 2 mL/kg died within 18-24 hours of treatment. Mice dosed at all three dose levels were drowsy, showing signs of stress, and exhibiting laboured breathing within 30 minutes. Within 1 hour of treatment mice were hypothermic. Within 2 hours of treatment the mice dosed at 10 mL/kg were comatose and those animals dosed at 2 and 5 mL/kg were semi-comatose. The surviving female mice recovered within 48 hours following treatment. Autopsy of the animals that died revealed distension of the stomach due to the presence of orange/yellow fluid. The stomach and intestines were very pale and the ileum was irritated and haemorrhaging present in some animals. These mice also exhibited pale livers and kidneys. The surviving females were normal in appearance at autopsy.

The dose level was converted from mL/kg bw to mg/kg bw, for classification, based on the specific gravity of the test material reported in this study.

Under the conditions of the study the approximate LD50 of the test material was determined to be between 2060 and 5015 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The key study was determined to be reliable with restrictions. The data taken from the supporting studies are in good agreement with the results of the key study and are sufficient to support the determined LD50 value. Collectively representing a dataset with good quality overall.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

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

Study period:

18 June 2012 to 11 July 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to valid guidelines and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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
- Age at study initiation: 8 - 12 weeks.
- Weight at study initiation: At least 200 g.
- Housing: Individually during exposure period and in groups of up to four, by sex, for the remainder of the study.
- Diet: Rodent diet ad libitum.
- Water: Mains drinking water, ad libitum.
- Acclimation period: at least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25 ºC
- Humidity (%): 30 - 70 %
- Air changes (per hr): at least 15 changes per hour.
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light.

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Backs and flanks of each animal, prepared by clipping free of hair the day before exposure.
- % coverage: Approximately 10% of the total body surface area.
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing: After the 24 hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test material.
- Time after start of exposure: 24 hours after exposure.

TEST MATERIAL
- Amount applied: 1.93 mL/kg

TEST PROCEDURE
- Initially one male and one female were tested to assess the toxicity of the test material. Animals were dosed in the same manner as the other test animals. No mortalities were observed so the remaining animals were dosed. The results were combined for evaluation.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 males and 5 females.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for deaths or overt signs of toxicity 0.5, 1, 2 and 4 hours after dosing and once daily thereafter for 14 days. Individual bodyweights were recorded prior to application of the test material on day 0 and on days 7 and 14.
- Necropsy of survivors performed: Yes (external examination and opening the abdomen and thoracic cavities to check for any macroscopic abnormalities).
- Other examinations performed: Following removal of the test material the test sites were examined for evidence of primary skin irritation and scored according to Draize (1977) (See "Any other information on materials and methods"), any other skin reactions, if present were also recorded.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: There were no deaths and no signs of overt toxicity.

Mortality:

There were no deaths.

Clinical signs:

other: There were no signs of systemic toxicity.

Gross pathology:

A cavity was noted in the right kidney of one male but this was considered to be a genetic defect and not related to treatment with the test material. No abnormalities were noted at necropsy of the remaining animals.

Other findings:

Dermal irritation: There were no signs of dermal irritation.

Table 2: Individual Bodyweights

Dose Level mg/kg	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight Change (g) During Week)
		0	7	14	1	2
2000	1-0 Male	275	294	316	19	22
	3-0 Male *	242	272	312	30	40
	3-1 Male	236	272	310	36	38
	3-2 Male	247	277	308	30	31
	3-3 Male	242	277	313	35	36
	2-0 Female	206	210	215	4	5
	4-0 Female	215	225	232	10	7
	4-1 Female	218	220	228	2	8
	4-2 Female	218	227	230	9	3
	4-3 Female	208	219	226	11	7

*Individual with the cavity in the right kidney.

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the study, the acute dermal LD50 was determined to be greater than 2000 mg/kg bw.

Executive summary:

The acute dermal toxicity of the test material was determined in a study conducted in compliance with standardised guidelines OECD 402 and EU Method B.3. During the study, two animals (one male and one female) were given a single, 24 -hour semi-occluded dermal application of the undiluted test material to intact skin at a dose level of 2000 mg/kg bw. Based on the results of the initial test, a further group of four males and four females was similarly treated. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

Under the conditions of the study, there were no deaths or overt signs of systemic toxicity. There were no signs of dermal irritation and all animals showed expected gains in bodyweight over the study period. At necropsy a cavity was noted in the right kidney of one male but this was considered to be a genetic defect and not related to treatment with the test material. No abnormalities were noted at necropsy of the remaining animals. In consideration of these findings the LD50 was determined to be greater than 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The key study was determined to be reliable without restriction. Further supporting information was in good agreement with results from the key study, indicating a good overall quality of the database.

Additional information

Oral

In the key study (Smith, 1979) the acute oral toxicity of the test material was determined by gavage in 4-5 week old mice, at 3 dose levels; 10.0, 5.0 and 2.0 mL/kg bw. Animals were observed for up to 7 days after exposure. All animals dying were autopsied and those surviving until termination were sacrifices and examined post mortem after 7 days. Two mice were dosed at the high and low dose levels and six for the middle dose level. Equal numbers of males and females were used. During the study both mice dosed with 10 mL/kg, four of the six mice dosed with 5 mL/kg and the one male mouse dosed at 2 mL/kg died within 18-24 hours of treatment. Mice dosed at all three dose levels were drowsy, showing signs of stress, and exhibiting laboured breathing within 30 minutes. Within 1 hour of treatment mice were hypothermic. Within 2 hours of treatment the mice dosed at 10 mL/kg were comatose and those animals dosed at 2 and 5 mL/kg were semi-comatose. The surviving female mice recovered within 48 hours following treatment. Autopsy of the animals that died revealed distension of the stomach due to the presence of orange/yellow fluid. The stomach and intestines were very pale and the ileum was irritated and haemorrhaging present in some animals. These mice also exhibited pale livers and kidneys. The surviving females were normal in appearance at autopsy. Under the conditions of the study the approximate LD50 of the test material was determined to be between 2060 and 5015 mg/kg bw. The study was assigned a reliability score of 1 in line with the principles for assessing data quality as defined by Klimisch (1997).

 

Supporting information is available in the form of a company website (Good Scents Company, 2011), a material safety data sheet (Sigma Aldrich, 2009), and other company data (Moreno, 1973). All acute toxicity data was taken from abstracts of information with no or few details reported on the methodology applied. All three sources report the acute oral toxicity of the test material to be > 5000 mg/kg bodyweight. As such all three studies were assigned a reliability score of 4 in accordance with the principles for assessing data quality defined by Klimisch (1997).

Inhalation

In accordance with point 8.5.2, Column 2 (Specific rules for adaptation from Column 1), Annex VIII of Regulation (EC) No. 1907/2006, an acute inhalation study does not need to be performed as the substance has a low vapour pressure. The acute toxicity endpoint has been addressed by assessing the toxicity via the oral and dermal routes, which is more appropriate when considering the properties of this substance.

Dermal

In the key study (Sanders, 2012), the acute dermal toxicity of the test material was determined in a study conducted in compliance with GLP and the standardised guidelines OECD 402 and EU Method B.3. During the study, two Wistar rats (one male and one female) were given a single, 24 –hour, semi-occluded dermal application of the undiluted test material to intact skin at a dose level of 2000 mg/kg bw. Based on the results of the initial test, a further group of four males and four females was similarly treated. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy at termination. Under the conditions of the study, there were no deaths and no overt signs of systemic toxicity. There were no signs of dermal irritation and all animals showed expected gains in bodyweight over the study period. At necropsy a cavity was noted in the right kidney of one male but this was considered to be a genetic defect and not related to treatment with the test material. No abnormalities were noted at necropsy of the remaining animals. In consideration of the findings, the acute dermal LD50 was determined to be > 2000 mg/kg. The study was assigned a reliability score of 1 in line with the principles for assessing data quality as defined by Klimisch (1997).

Supporting information is available in the form of a company website (Good Scents Company, 2011), a material safety data sheet (Sigma Aldrich, 2009), and other company data (Moreno, 1973). All supporting acute toxicity data was taken from abstracts of information with no or few details reported on the methodology applied. All three sources report the acute dermal toxicity of the test material to be > 5000 mg/kg bw. As such, all three studies were assigned a reliability score of 4 in accordance with Klimisch (1997).

Justification for selection of acute toxicity – oral endpoint

The key study was conducted to sound scientific principles with a sufficient level of reporting to assess the quality of the data submitted. Accordingly the study was assigned a reliability score of 2 according to the criteria of assessing data quality as defined by Klimisch (1997).

Justification for selection of acute toxicity – inhalation endpoint

Data waiver has been submitted to address acute toxicity via the inhalation route.

Justification for selection of acute toxicity – dermal endpoint

Study was conducted to GLP and standardised guidelines with a high level of reporting and was assigned a reliability score of 1 according to the criteria of Klimisch.

Justification for classification or non-classification

According to the criteria outlined in Regulation (EC) No. 1272/2008 and Directive 67/548/EEC, the substance does not meet the criteria for classification for acute oral or dermal toxicity.