Exo-1-methyl-4-(1-methylethyl)-7-oxabicyclo[2.2.1]heptan-2-ol

Endpoint summary

Description of key information

Acute oral toxicity: The LD50 for male and female rats were calculated to be 1429 mg/kg (95% CI: 1169 -1689) and 1053 mg/kg (95% CI: 952 - 1154), respectively. The combined LD50 was calculated to be 1293 mg/kg (95% CI: 1123 -1464).

Acute inhalative toxicity: Based on the available data, an LC50 of approximately 10 mg/L is assumed.

Acute dermal toxicity: The LD50 of the test item in male and female rats was greater than 2000 mg/kg.

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:

1986-02-07 to 1986-03-11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Young adult male and female Sprague-Dawley rats were obtained from Charles River Breeding Laboratories, Inc., Wilmington, MA.
- Age at study initiation: Young adult
- Weight at study initiation: males: 195.8 to 221.8 g; females: 204.0 to 224.6 g
- Fasting period before study: Yes. Animals were fased overnight (approximately 18 hours) prior the test.
- Housing: Animals were individually housed in wire mesh bottom cages.
- Diet: NIH open formula 07, certified feed (Zeigler Brothers, Inc., Gardners, PA); ad libitum
- Water: Fresh tap water; ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

corn oil

Doses:

900, 1046, 1216, 1643, 2220 and 3000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were weighted on the day of dosing (day 1) and on day 8 and 15 of the study. All animals will be observed for mortlity and toxic signs frequently during the day of dosing and twice daily (at least 5 hours apart) thereafter for a toal of 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, cage side observations will include changes in the fur and skin; eyes and mucous membranes; respiratory, circulatory, autonomic and central nervous systems; somatomotor activity and behavior pattern, observation of tremors, convulsions, salivation, diarrhea, lethargy, and coma.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

1 429 mg/kg bw

Based on:

test mat.

95% CL:

>= 1 169 - <= 1 689

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

1 053 mg/kg bw

Based on:

test mat.

95% CL:

>= 952 - <= 1 154

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 293 mg/kg bw

Based on:

test mat.

95% CL:

>= 1 123 - <= 1 464

Mortality:

All male rats died in the two highest dose groups of 2220 and 3000 mg/kg. All female animals died in the four highest dose groups. For details see table 1 in the section 'Any other information on results incl. tables'.

Clinical signs:

See table 1 in the section 'Any other information on results

Gross pathology:

See table 2 in the section 'Any other information on results

Table 1: Incidence of daily observations

Dose Level mg/kg	Observations	No. Affected/No. Examined
		Males	Females
900	Ataxia	5/5	5/5
	Decreased activity	4/5	5/5
	Salivation	1/5	3/5
	Lacrimation	0/5	4/5
	Appears to have blood in urine	0/5	1/5
	Wet abdomen	0/5	3/5
1046	Ataxia	4/5	5/5
	Decreased activity	2/5	5/5
	Salivation	2/5	1/5
	Lacrimation	1/5	4/5
	Appears to have blood in urine	0/5	1/5
	Wet abdomen	0/5	4/5
	Hair loss-abdomen	0/5	1/5
	Death	1/5	2/5
1216	Ataxia	4/5	4/5
	Decreased activity	3/5	5/5
	Salivation	2/5	3/5
	Appears to have blood in urine	1/5	0/5
	Lacrimation	1/5	4/5
	Wet abdomen	1/5	0/5
	Death	1/5	5/5
1643	Ataxia	4/5	1/5
	Decreased activity	4/5	5/5
	Salivation	1/5	3/5
	Wet abdomen	1/5	0/5
	Lacrimation	1/5	3/5
	Death	3/5	5/5
2220	Salivation	4/5	3/5
	Decreased activity	5/5	5/5
	Ataxia	1/5	2/5
	Lacrimation	0/5	3/5
	Death	5/5	5/5
3000	Decreased activity	5/5	5/5
	Ataxia	2/5	3/5
	Salivation	2/5	2/5
	Lacrimation	0/5	1/5
	Death	5/5	5/5

Table 2: Incidence of Necropsy Findings

Dosage Level mg/kg	Findings	No. Affected/No. Examined
		Males	Females
900	No noteworthy findings	2/5	5/5
	Lungs: multiple dark spots	3/5	0/5
1046	No noteworthy findings	4/5	3/5
	Thoracic cavity: contains bloodlike liquid	1/5	0/5
	Lungs: dark and/or red areas	1/5	1/5
	Liver: pale	0/5	1/5
	Bladder: contains bloodlike liquid	0/5	1/5
1216	External appearance: corneal opacity (left eye)	0/5	2/5
	No noteworthy findings	4/5	0/5
	Lungs: puffy (dark)	1/5	2/5
	Thymus: red spots	1/5	3/5
	Liver: dark	1/5	4/5
	Stomach (pyloric region): small red nodule	1/5	1/5
	Stomach (pyloric region): red	0/5	1/5
1643	External appearance: corneal opacity (right eye)	1/5	0/5
	No noteworthy findings	2/5	1/5
	Thymus: red spot	1/5	0/5
	Lungs: puffy	3/5	0/5
	Lungs: dark red areas	0/5	1/5
	Lungs: pale	1/5	0/5
	Liver: dark	3/5	3/5
	Stomach (pyloric region): rad nodule	1/5	0/5
	Stomach (pyloric region): red	1/5	0/5
2220	External appearance: corneal opacity (left eye)	0/5	1/5
	Liver: dark	4/5	5/5
	Lungs: puffy	1/5	2/5
	Lungs: pale	1/5	0/5
	Lungs: dark spots	1/5	0/5
	Thymus: red spots	0/5	2/5
	Stomach (pyloric region): red areas	0/5	1/5
3000	External appearance: corneal opacity (left eye)	0/5	1/5
	Lungs: puffy (pale)	4/5	4/5
	Liver: dark	5/5	5/5
	Thymus: red spots	0/5	1/5
	Stomach 8pyloric region). Red areas	0/5	1/5

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 293 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1985-06-21 to 1985-07-05

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Exposure duration less than 4 hours

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Wilmington, Massachusetts
- Age at study initiation: Young adult
- Weight at study initiation: Males: 219 ± 6; Females: 233 ± 5
- Housing: The animals were individually housed in wire-mesh cages during the exposure.
- Diet: Food (NIH Open Formula 07, certified rodent diet, Zeigler Brothers, Inc., Gardners, PA) was supplied ad libitum before the test and during the post-exposure phases. The animals received no food during the exposure period.
- Water: Tap water was supplied ad libitum before the test and during the post-exposure phases. The animals received no water during the exposure period.
- Acclimation period: Yes, at least 5 days.

ENVIRONMENTAL CONDITIONS
- Airflow rate: 10 L/minute
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure was performed in a 123 L acrylic (plexiglass) chamber.
- Source and rate of air: The total airflow through the chamber was maintained at a rate of 30 L/minute using a transvector jet (Model 901, Vortec Corporation, Cincinnati, OH) and monitored using a prestandardized pressure gauge attached to the transvector jet.
- Method of conditioning air: The test atmosphere was vented via an air treatment system (Charles Spengler and Associates, Cincinnati, OH) constructed of a glass fiber pre-filter, Micretain® HEPA filter and an activated charcoal bank. The test substance was heated and maintained between 65 and 69 °C. Airflow rate of 10 L/minute was passed through the heated test substance. The resultant vapor/air mixture was delivered into the exposure chamber at an air inlet port, which allows the test article and incoming air to mix evenly within the chamber at the top before being drawn down over the animals.
- Airflow rate: 10 L/minute
- Total airflow through system: 2400 L
- Temperature in air chamber: 23-27 °C
- Humidity in air chamber: 53-58 %

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

80 min

Remarks on duration:

Twenty minutes were added to the 60 minutes exposure period in order to allow the test system to reach 99 percent of the desired concentration (point of equilibration).

Concentrations:

12.8 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animal observations for pharmacotoxic signs and mortality were recorded periodically during exposure, subsequent to exposure on day one and twice daily thereafter. Individual body weight data were recorded on day 1 (just prior to exposure), 8 and 15.
- Necropsy of survivors performed: Not specified

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 12.8 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

80 min

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.27 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: The exposure period was extrapolated to 4 h using the modified Haber's Law.

Mortality:

No mortality or signs of toxicity were noted in any animal during the 14 day post-exposure period.

Clinical signs:

other: None.

Body weight:

The test substance exposure did not exhibit an adverse effect upon body weight gain in either sex.

The classification criteria for acute inhalation toxicity relate to a 4 hour experimental exposure period. But, under the conditions of this test, the test animas were exposed to the test substance for only 1.3 h. If data for a 4 -hour period are not available then extrapolation of the results to 4 hours can be achieved using the modified Haber's Law according to ECHA Guidance document Chapter R7a: Endpoint specific guidance (July 2017).

 

Extrapolation of the results to 4 hours using the modified Haber's Law:

 

C1ⁿ* t1 = K = C2 * t2

C2 = C1ⁿ* t1 / t2

C2 = 12.8 mg*h/L * 1.3 h / 4 h = 4.27 mg/L

 

C1 = 12.8 mg/L

t1= 1.3

t2 = 4 h

n = 1 (default value for extrapolation to longer duration) 

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1985-06-14 to 1985-06-15

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Exposure duration less than 4 hours

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Wilmington, Massachusetts
- Age at study initiation: Approximately 8 weeks
- Weight at study initiation: 230 to 250 g.
- Housing: The animals were individually housed in wire-mesh cages during the exposure.
- Diet: Food (NIH Open Formula 07, certified rodent diet, Zeigler Brothers, Inc., Gardners, PA) was supplied ad libitum before the test. The animals received no food during the exposure period.
- Water: Tap water was supplied ad libitum before the test. The animals received no water during the exposure period.
- Acclimation period: Yes, at least 5 days.

ENVIRONMENTAL CONDITIONS
- Airflow rate: 65 L/minute
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure was performed in a 128 L acrylic (plexiglass) chamber.
- Source and rate of air: Total airflow through the chamber was maintained at a rate of 65 L/minute using a transvector jet (Model 901, Vortec Corporation, Cincinnati, OH) and monitored using a prestandardized pressure gauge attached to the transvector jet.
- Method of conditioning air: The test atmosphere was vented via an air treatment system (Charles Spengler and Associates, Cincinnati, OH) constructed of a glass fiber pre-filter, Micretain® HEPA filter and an activated charcoal bank. The test article was delivered into the exposure chamber by means of a pressure spray set-up (1/4 J atomizer with 2050ss fluid cap and 67-6-20-70ss air cap, Spraying Systems, Inc., Wheaton, IL) connected to a peristaltic pump. The test article was delivered into the exposure chamber at an air inlet port, which allows the test article and incoming air to mix evenly within the chamber at the top before being drawn down over the animals.
- Total exposure duration: 69 minutes
- Chamber volume: 128 L
- Airflow rate: 65 L/minute
- Total airflow through system: 4485 L
- Temperature in air chamber: 19-23 °C
- Humidity in air chamber: 44-63 %

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

1.15 h

Remarks on duration:

Nine minutes were added to the 60 minute exposure period in order to allow the test system to reach 99 percent of the desired concentration (point of equilibration)

Concentrations:

201.6 mg/L

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed frequently during exposure and twice daily thereafter.
- Necropsy of survivors performed: Yes, all animals were subjected to a gross necropsy and examined for lesions and abnormalities.The individual body weight were recorded on day 1 (just prior to exposure) and at death.

Key result

Sex:

male/female

Dose descriptor:

LC100

Effect level:

57.96 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: The exposure period was extrapolated to 4 h using the modified Haber's Law.

Sex:

male/female

Dose descriptor:

LC100

Effect level:

201.6 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

1.15 h

Mortality:

Mortality occured in all animals by study day 2. Eight of the ten animals died during the exposure period.

Clinical signs:

other: Pharmacotoxic signs noted during and immediately following exposure were ataxia, decreased activity and labored breathing.

Gross pathology:

Nasal Passages: The nasal passages of all animals were reddened and/or contained clear fluid.
Lungs: The lungs of three animals were bright red.
Trachea: The trachea of seven animals contained clear fluid.
Corneal opacity: Corneal opacity was noted in one or both eyes in eight animals.
Wet coat: The coats of all animals were wet as a result of whole-body aerosol exposure. This finding indicates dermal and/or oral (via preening) test item exposure occurred in conjunction with the inhalation exposure.
The aforementioned findings noted in the nasal passages, lungs and trachea are suggestive of pulmonary irritation and inflammation.

The classification criteria for acute inhalation toxicity relate to a 4 hour experimental exposure period. But, under the conditions of this test, the test animas were exposed to the test substance for only 1.15 h. If data for a 4 -hour period are not available then extrapolation of the results to 4 hours can be achieved using the modified Haber's Law according to ECHA Guidance document Chapter R7a: Endpoint specific guidance (July 2017).

 

Extrapolation of the results to 4 hours using the modified Haber's Law:

 

C1ⁿ* t1 = K = C2 * t2

C2 = C1ⁿ* t1 / t2

C2 = 201.6 mg*h/L * 1.15 h / 4 h = 57.96 mg/L

 

C1 = 201.6 mg/L

t1= 1.15

t2 = 4 h

n = 1 (default value for extrapolation to longer duration) 

Reference 3

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1985-06-19 to 1985-07-03

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Exposure duration less than 4 hours

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Chrales River Breeding Laboratories, Inc., Wilmington, Massachusetts
- Age at study initiation: Approximately 8 weeks
- Weight at study initiation: 215 - 258 g
- Fasting period before study:
- Housing: The animals were individually housed in wire-mesh cages during the exposure.
- Diet: Food (NIH Open Formula 07, certified rodent diet, Zeigler Brothers, Inc., Gardners, PA) was supplied ad libitum before the test and during the post-exposure phases. The animals received no food during the exposure period.
- Water: Tap water was supplied ad libitum before the test and during the post-exposure phases. The animals received no water during the exposure period.
- Acclimation: Yes, at least 5 days.

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure was performed in a 128 L acrylic (plexiglass) chamber.
- Source and rate of air: The total airflow through the chamber was maintained at a rate of 65 L/minute using a transvector jet (Model 901, Vortec Corporation, Cincinnati, OH) and monitored using a prestandardized pressure gauge attached to the transvector jet.
- Method of conditioning air: The test atmosphere was vented via an air treatment system (Charles Spengler and Associates, Cincinnati, OH) constructed of a glass fiber pre-filter, Micretain® HEPA filter and an activated charcoal bank. The test substance was delivered into the exposure chamber by means of a pressure sray set-up (1/4 J atomizer with 2050ss fluid cap and 67-6-20-70ss air cap, Spraying Systems, Inc., Wheaton, IL) connected to a peristaltic pump. The test article was delivered into the exposure chamber at an air inlet port, which allows the test substance and incoming air to mix evenly within the chamber at the top before being drawn over the animals.
- Airflow rate: 65 L/minute
- Total airflow through system: 4485 L
- Temperature in air chamber: 20-28 °C
- Humidity in air chamber: 49-85 %

Duration of exposure:

1.15 h

Concentrations:

45.2 mg/L

No. of animals per sex per dose:

5

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animal observations for pharmacotoxic signs and mortality were recorded periodically during exposure, subsequent to exposure on day one and twice daily during the 14-day post-exposure period. Individual body weight data were recorded on day 1 (just prior to exposure), 8 and 15, or at death.
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

< 13 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: The exposure period was extrapolated to 4 h using the modified Haber's Law.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

< 45.2 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

1.15 h

Mortality:

Mortality occured in three males and three females at day 2 of the study.

Clinical signs:

other: Decreased levels of activity and labored breathing were noted in all animals during and immediately following exposure. These findings cleared among surviving animals during post-exposure week one. Alopecia was noted in three of four surviving animals fro

Body weight:

The test substance did not exhibit an adverse effect upon body weight gain among surviving males. Weight loss was recorded in one female at day 15.

Gross pathology:

Nasal Passages: The nasal passages of all animals were reddened and contained clear fluid.
Lungs: Four of the six animals had bright red lung.
Trachea: The trachea of two animals contained clear fluid. The aforementioned findings are suggestive of pulmonary irritation and inflammation.

Other findings:

Following exposure, the animals' coat were wet as a result of whole-body aerosol exposure. This finding is significant because it suggests dermal and oral (via preening) test substance exposure continued following removal of the animals from the test chamber.

The classification criteria for acute inhalation toxicity relate to a 4 hour experimental exposure period. But, under the conditions of this test, the test animas were exposed to the test substance for only 1.15 h. If data for a 4 -hour period are not available then extrapolation of the results to 4 hours can be achieved using the modified Haber's Law according to ECHA Guidance document Chapter R7a: Endpoint specific guidance (July 2017).

 

Extrapolation of the results to 4 hours using the modified Haber's Law:

 

C1ⁿ* T1 = K = C2 * t2

C2 = C1ⁿ* t1 / t2

C2 = 45.2 mg*h/L * 1.15 h / 4 h = 13 mg/L

 

C1 = 45.2 mg/L

t1= 1.15

t2 = 4 h

n = 1 (default value for extrapolation to longer duration) 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

10 000 mg/m³

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:

1988-03-08 to 1988-03-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: The test substance was stored in the dark at ambient temperature.

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rats were received from a commercial supplier (Charles River U.K. Ltd.)
- Age at study initiation: 9-11 weeks
- Housing: On arrival the rats were housed in single sex groups of up to 12 to a cage; each cage measured 56 cm x 38 cm x 18 cm. The animals were quarantined in non-barriered animal rooms with access restricted to essential personnel. Prior to experimentation the animals were rehoused (as single sex group of four) in cages with stainless-steel wire-mesh floors and tops; each cage measured 38 cm x 25 cm x 18 cm. Paper-lined trays for excreta were places beneath each cage.
- Diet: PRD, labsure Animal Foods; ad libitum
- Water: Public water supply; ad libitum
wire

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25 °C
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal
- % coverage: 60% of the dorsal hair were shorn with electric clippers and the gauze pad with the required amount of test material was applied to the shorn skin
- Type of wrap if used: The gauze pad was held in place with adhesive tape.

REMOVAL OF TEST SUBSTANCE
- Washing: The skin washed with warm dilute detergent solution and dried.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The test material was administered as a powder with 0.1 mL water.

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.1 mL water

Duration of exposure:

24 h

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

None

Clinical signs:

No treatment related changes in behavior and demeanour were observed during the 14 day observation period.

Body weight:

All rats had gained weight relative to their day 1 bodyweights by the end of the study.

Gross pathology:

At necropsy no treatment releated macroscopic changes were recorded.

The only unusual finding recorded was the presence of liquid contents in the stomach of one male rat. This was not considered to be related to treatment.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Acute oral toxicity:

In an acute toxicity study 5 male and female Sprague-Dawley rats were administered by gavage to test substance concentrations of 900, 1046, 1216, 1643, 2220 and 3000 mg/kg. The animals were observed for mortality and toxic signs for a total of 14 days. All animals were subjected to a gross necropsy and abnormalities were noted. All male rats died in the two highest dose groups of 2220 and 3000 mg/kg. All female animals died in the four highest dose groups. At all dose levels animals with ataxia was observed. The LD50 for male and female rats were calculated to be 1429 mg/kg (95% CI: 1169 -1689) and 1053 mg/kg (95% CI: 952 - 1154), respectively. The combined LD50 was calculated to be 1293 mg/kg (95% CI: 1123 -1464).

A second acute toxicity study is available, however only one dose of 5000 mg/kg bw was tested. This dose corresponded to the LD80 combined for males and females.

Acute inhalation toxicity:

Three acute inhalation studies with the test substance are available. In each test five male and five female Sprague-Dawley rats were tested and exposed to the test substance for approximately for 1 hour. Since the classification criteria for acute inhalation relate to a 4 hour experimental exposure period, the results were extrapolated to 4 hours using the modified Haber’s law.

In one of the tests the rats were exposed to a vapour generated from the test substance at a nominal concentration of 12.7 mg/L for 80 minutes. This relates to an extrapolated value of 4.27 mg/L after 4 hours. Under the conditions of this study, the test substance failed to produce mortality or signs of toxicity.

In the two other studies the rats were exposed to a liquid droplet aerosol of the test substance for 1.15 hours. In one study the test animals were exposed to a nominal test item concentration of 201.6 mg/L, which relates to an extrapolated value of 57.96 mg/L after 4 hours. This concentration resulted in 100% mortality of the test animals. In the other study the rats were exposed to a test item concentration of 45.2 mg/L, which relates to an extrapolated value of 13 mg/L after 4 hours. Under the conditions of this aerosol study, the test item produced mortality in three male and three female animals. Based on this result an LC50 of approximately 10 mg/L is assumed.

Acute dermal toxicity:

In an acute dermal toxicity study 5 male and female rats were exposed to an single dose of the test substance of 2000 mg/kg administered as a wetted powder. After an exposure period of 24 hours the animals were observed for signes of toxicity for a 14 day observation period. All of the 5 male and female rats exposed to a single dermal application of 2000 mg of the test item/kg bw survived the post exposure periode. They were subjected to detailed necropsy. The only unusual finding recorded was the presence of liquid contents in the stomach of the male rat. This was not considered to be related to treatment.

Thus, under the conditions of this test, the acute dermal LD50 of the test material in male and female rats, administered as a wetted powder, was greater than 2000 mg/kg.

Specific target organ toxicity - single exposure:

In both acute oral toxiticity studies, ataxia and decreased was described as clinical observation following dosing. Additionally, in a 28 -day oral toxicity study, all top dose animals (1000 mg/kg bw/d) were comatose within a few hours of their first dose, except one male which became ataxic and then died and two males which were ataxic for about 5 hours. The coma lasted several hours, most animals recovered overnight but some died in coma or were humanely killed the next day; two others died or were killed after being comatose subsequent to their second dose. These effects are in line with transient narcotic effects of the test substance. Therefore, classification with STOT SE 3 (H336) is warranted.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on acute toxicity, the test item is to be classified for acute oral toxicity, cat. 4, H302 (Harmful if swallowed) and as STOT SE 3, H336 (May cause drowsiness or dizziness) according to Regulation (EC) No 1272/2008 (CLP), as amended for the tenth time in Regulation (EU) No 2017/776.