2-ethoxybenzoic acid

Acute Toxicity: dermal

Administrative data

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 experimental study report.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

This study was designed to determine the dermal LD50 of the test item (up to 2000 mg/kg) or to establish a non-lethal dose level of 2000 milligram of test item per kilogram of body weight.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-ethoxybenzoic acid

EC Number:

205-130-3

EC Name:

2-ethoxybenzoic acid

Cas Number:

134-11-2

Molecular formula:

C9H10O3

IUPAC Name:

2-ethoxybenzoic acid

Test material form:

liquid

Details on test material:

- Name of test material (IUPAC name): 2-Ethoxybenzoic Acid
- Molecular formula: C9H10O3
- Molecular weight: 166.175 g/mol
- Smiles notation: CCOc1ccccc1C(=O)O
- InChl: 1S/C9H10O3/c1-2-12-8-6-4-3-5-7(8)9(10)11/h3-6H,2H2,1H3,(H,10,11)
- Substance type: Organic
- Form: Liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: National Institute of Biosciences, Pune.
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: Young adult (8 to 10 weeks old) female rats were used.
- Weight at study initiation: The weight range of approximately 220.2 to 240.6 grams at initiation of dosing.
Body weights at the start : Female Mean : 231.34 g (= 100 %); Minimum : 220.2 g (- 4.82 %); Maximum : 240.6 g (+ 4.00 %)
- Identification: Each rat was individually identified by the cage number.
- Housing: The rats were individually housed in polycarbonate cages with paddy husk as bedding.
- Diet (e.g. ad libitum): Rodent feed supplied by the Nutrivet Life Sciences, Pune, was provided ad libitum from individual feeders.
- Water (e.g. ad libitum): Water was provided ad libitum from individual bottles attached to the cages. All water was from a local source and passed through the reverse osmosis membrane before use.
- Acclimation period: 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.2 to 21.8 degree centigrade.
- Humidity (%): 56.0% to 59.1%.
- Air changes (per hr): The animal room was independently provided with at least ten to fifteen air changes per hour of 100% fresh air that had been passed through the HEPA filters.
- Photoperiod (hrs dark / hrs light): An artificial light and dark cycle of 12 hours each was provided to the room.

IN-LIFE DATES: 11-09-2017 to 24-11-2017

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal surface and sides from scapular to pelvic area
- % coverage: at least 10% of the body surface area.
- Type of wrap if used: The test item was held in contact with the skin using a porous gauze dressing and non irritating tape around the animal to cover the exposure site for first 24 hours exposure period. Elizabethan collar was placed on each animal for first 24 hours after application of the test item. These collars prevent ingestion of test item.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The wrapping was removed and the test site wiped free of excess test item. Distilled water was used to remove residual test item.
- Time after start of exposure:24 hours

Duration of exposure:

24 hours

Doses:

Dose Range Finding Study:
Group I : 200 mg/kg
Group I : 1000 mg/kg
Group I : 2000 mg/kg
Main Study:
Group II : 2000 mg/kg

No. of animals per sex per dose:

Total No. of animals : 5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Twice daily
- Necropsy of survivors performed: yes, necropsy was performed on animals surviving at the end of the study. Macroscopic examination of all the orifices, cavities and tissues were made and the findings were recorded. All animals surviving the study period were sacrificed by the carbon dioxide asphyxiation technique (day 15).
- Other examinations performed:
Clinical Observations and General Appearance: Animals were observed for clinical signs, mortality, until sacrifice. Onset, duration and severity of any sign were recorded. The clinical signs and mortality observations were conducted at 10, 30, 60 minutes, 2, 4 and 6 hours on the day of dosing and once daily thereafter for 14 day. Daily observation was done as far as possible at the same time. The observations included general clinical signs, observations of eyes, mucous membranes, respiratory, circulatory system and behavior pattern.
Evaluation of Dermal Reaction: Dermal reaction was observed daily for study period of 14 days.
Body weights: Individual animal body weights were recorded pre-test (prior to administration of the test item), day 7 and at termination on day 14.
Histopathology: No gross abnormalities were observed in animals sacrificed terminally hence, no histopathology was performed.

Statistics:

not specified

Results and discussion

Preliminary study:

Dose Range Finding Study: A single dose of 200 mg/kg body weight of the test item was administered to 1 female animal. No death or clinical signs of toxicity was observed during first 48 hours, hence, additional 1 female animal was administered at the dose of 1000 mg/kg body weight. Administration of 1000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours, hence, additional 1 female animal was administered at the dose of 2000 mg/kg body weight. Administration of 2000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours.

Effect levels

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:

Dose Range Finding Study: The animals survived through the study period of 14 days treated at the dose level of 200 mg/kg, 1000 mg/kg and 2000 mg/kg.
Main Study: All animals survived through the study period of 14 days treated at the dose level of 2000 mg/kg body weight.

Clinical signs:

other: Dose Range Finding Study: Animal treated at the dose level of 200 mg/kg, 1000 mg/kg and 2000 mg/kg did not result in any signs of toxicity during the study period of 14 days. Main Study: Animals treated at the dose level of 2000 mg/kg body weight did not

Gross pathology:

Gross pathological examination did not reveal any abnormalities in animals from 200 mg/kg, 1000 mg/kg and 2000 mg/kg dose groups from dose range finding study and main study sacrificed terminally.

Other findings:

Evaluation of Dermal Reaction
Dose Range Finding Study: Animal treated at the dose level of 200 mg/kg, 1000 mg/kg and 2000 mg/kg body weight did not result in any skin reaction during the study period of 14 days.
Main Study: Animals treated at the dose level of 2000 mg/kg body weight did not result in any skin reaction during the study period of 14 days.

Any other information on results incl. tables

Table No. I 

Summary of Clinical Signs of Toxicity and Mortality

 

Laboratory Test Item Code :TAS/122/057

Test System : Sprague Dawley Rat

Sex : Female

Dose Finding Study:

Group  No.	Dose mg/kg	Observed Signs	Total Number of Animals	Animal Nos.	Period of signs in days  From - to	Mortality
I	200	No clinical signs observed	1	1	Day 0 - Day 14	0/1

 

Group  No.	Dose mg/kg	Observed Signs	Total Number of Animals	Animal Nos.	Period of signs in days  From - to	Mortality
I	1000	No clinical signs observed	1	2	Day 0 - Day 14	0/1

 

Group  No.	Dose mg/kg	Observed Signs	Total Number of Animals	Animal Nos.	Period of signs in days  From - to	Mortality
I	2000	No clinical signs observed	1	3	Day 0 - Day 14	0/1

 

Main Study:

Group  No.	Dose mg/kg	Observed Signs	Total Number of Animals	Animal Nos.	Period of signs in days  From - to	Mortality
II	2000	No clinical signs observed	2	4, 5	Day 0 - Day 14	0/2

 

Table No. II

Summary of Evaluation of Dermal Reaction

 

Laboratory Test Item Code :TAS/122/057

Test System : Sprague Dawley Rat

Sex : Female

Dose Finding Study:

Group  No.	Dose mg/kg	Dermal Reaction	Total Number of Animals	Animal Nos.	Period of signs in days  From - to
I	200	No dermal reaction observed	1	1	Day 0 - Day 14

 

Group  No.	Dose mg/kg	Dermal Reaction	Total Number of Animals	Animal Nos.	Period of signs in days  From - to
I	1000	No dermal reaction observed	1	2	Day 0 - Day 14

 

Group  No.	Dose mg/kg	Dermal Reaction	Total Number of Animals	Animal Nos.	Period of signs in days  From - to
I	2000	No dermal reaction observed	1	3	Day 0 - Day 14

 

Main Study:

Group  No.	Dose mg/kg	Dermal Reaction	Total Number of Animals	Animal Nos.	Period of signs in days  From - to
II	2000	No dermal reaction observed	2	4, 5	Day 0 - Day 14

 

Table No.III 

Mean Body Weight and Percent Body Weight Gain (g)

 

Laboratory Test Item Code :TAS/122/057

Test System : Sprague Dawley Rat

Sex : Female

Dose Finding Study:

Group No.	Dose (mg/kg body weight)		Body weight Day 0	Body weight Day 7	% body weight gain day 0-7	Body weight Day 14	% body weight gain day 7- 14	% body weight gain day 0- 14
I	200	Mean	224.8	238.5	6.09	250.2	4.91	11.30
		± SD	-	-	-	-	-	-

 

Group No.	Dose (mg/kg body weight)		Body weight Day 0	Body weight Day 7	% body weight gain day 0-7	Body weight Day 14	% body weight gain day 7- 14	% body weight gain day 0- 14
I	1000	Mean	220.2	235.6	6.99	248.4	5.43	12.81
		± SD	-	-	-	-	-	-

 

Group No.	Dose (mg/kg body weight)		Body weight Day 0	Body weight Day 7	% body weight gain day 0-7	Body weight Day 14	% body weight gain day 7- 14	% body weight gain day 0- 14
I	2000	Mean	232.4	245.5	5.64	256.7	4.56	10.46
		± SD	-	-	-	-	-	-

 

Main Study:

Group No.	Dose (mg/kg body weight)		Body weight Day 0	Body weight Day 7	% body weight gain day 0-7	Body weight Day 14	% body weight gain day 7- 14	% body weight gain day 0- 14
II	2000	Mean	239.65	247.35	3.21	257.15	3.93	7.29
		± SD	1.34	6.86	2.28	12.94	2.35	4.80

 

Table No.IV

Summary of Gross Pathological Findings

 

Laboratory Test Item Code :TAS/122/057

Test System : Sprague Dawley Rat

Sex : Female

Dose Finding Study:

Group No.	Dose mg/kg	Animal Numbers	Animal Fate	Gross Pathological Findings
I	200	1	TS	No abnormality detected

 

Group No.	Dose mg/kg	Animal Numbers	Animal Fate	Gross Pathological Findings
I	1000	2	TS	No abnormality detected

 

Group No.	Dose mg/kg	Animal Numbers	Animal Fate	Gross Pathological Findings
I	2000	3	TS	No abnormality detected

 

                    Main Study:

Group No.	Dose mg/kg	Animal Numbers	Animal Fate	Gross Pathological Findings
II	2000	4, 5	TS	No abnormality detected

 

                     TS = Terminal Sacrifice 

 

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Conclusions:

It was concluded that the acute dermal median lethal dose (LD50) of the given test chemical, when administered to female Sprague Dawley rats was considered to be >2000 mg/kg body weight. Thus, according to CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not classify as an acute dermal toxicant. CLP Classification: “Not classified”.

Executive summary:

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 Sprague Dawley rats.

In the dose range finding study, a single dose of 200 mg/kg body weight of the test item was administered to 1 female animal. No death or clinical signs of toxicity was observed during first 48 hours, hence, additional 1 female animal was administered with the dose of 1000 mg/kg body weight. Administration of 1000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours, hence, additional 1 female animal was administered at the dose of 2000 mg/kg body weight. Administration of 2000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours.

As the dose range finding study revealed no mortality or clinical signs at the maximum dose of 2000 mg/kg, the main study was initiated with two additional animals.  The animals were administered with a dose of 2000 mg/kg body weight in sequential manner at 48 hours intervals. Animals from dose range finding study treated at the dose levels of 200 mg/kg, 1000 mg/kg and 2000 mg/kg and animals from main study treated at the dose level of 2000 mg/kg exhibited normal body weight gain and revealed no clinical signs of toxicity or mortality during the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment.

It was concluded that the acute dermal median lethal dose (LD50) of the given test chemical, when administered to female Sprague Dawley rats was considered to be >2000 mg/kg body weight. Thus, according to CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not classify as an acute dermal toxicant. CLP Classification: “Not classified”.