3-methylbutan-1-ol

Endpoint summary

Description of key information

oral:
LD50 > 5000mg/kg
Additionally, all LD50 values of the category members were found to be far greater than 2000 mg/kg bw.
inhalation:
No mortalities occured when 3-methylbutan-1-ol or the read-across substances were applied as vapour. In a study in which CAS 94624-12-1 was applied as an aerosol, the LC50 in mice was found to be below 14 mg/L, but above 14mg/L in rats and guinea pigs.
dermal:
All the dermal LD50 value were found to be greater than 2000 mg/kg bw.

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:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

only 2 dose groups

Principles of method if other than guideline:

Internal BASF-method was used which was in large part equivalent to method described in OECD guideline 401

GLP compliance:

no

Test type:

standard acute method

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: mean 220 g (males), 170 g (females)
- Fasting period before study: 15 - 20 hours
- Diet: Herilan MRH-Haltung; H Eggersmann KG; ad libitum
- Water: ad libitum

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 21.5, 50%
- Amount of vehicle (if gavage): 10 ml/kg bw

Doses:

2150, 5000 mg/kg bw

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: Daily recording of signs and symptoms from the day of administration till the end of the observation period. Daily check (twice) for moribund and dead animals (once during the weekend).
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, pathology.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

5000 mg/kg bw: 1/5 female within 24 h
2150 mg/kg bw: 1/5 female within 48 h

Clinical signs:

other: Following symptoms were observed in both test groups up to 5 hours after treatment: dyspnoe, apathy, abnormal position, staggering, erythrodermia and poor general state. Rattling, atony, paresis of forelimbs, salivation and lacrimation were also observed

Gross pathology:

Surviving animals: nothing abnormal detected; dead animals: acute congestive hyperemia in the heart and cardiodilatation

Body weights:

Days after treatment	Mean body weight (g)
	2150 mg/kg bw treatment group		5000 mg/kg bw treatment group
	Males	Females	Males	Females
0	260	170	180	170
2-3	287	175	198	174
7	311	188	236	197
13	333	198	265	208

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

5 000 mg/kg bw

Quality of whole database:

reliable studies conducted similar to OECD Guideline, sufficient for assessment

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

(1981)

Principles of method if other than guideline:

Internal BASF-method (Inhalation Hazard Test) was used which was in large part equivalent to method described in OECD guideline 403 (1981).

GLP compliance:

no

Test type:

other: inhalation hazard test

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: mean 206 g (males), 172.5 g (females)
- Diet: Herilan MRH-Haltung; H Eggersmann KG; ad libitum
- Water: ad libitum

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- System of generating particulates/aerosols: vapour generated by bubbling 200 L/h air through a substance column of about 5 cm above a fritted glass disc in a glass cylinder.

Analytical verification of test atmosphere concentrations:

no

Remarks:

The nominal concentration was calculated as quotient of the amount of test substance weight loss during exposure, and the amount of air used during exposure

Duration of exposure:

7 h

Concentrations:

No verification of the concentration was performed. The test atmosphere is supposed to be saturated with test substance vapor at approximately 11.05 mg/l (3070.2 ppm)

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: group wise documentation on working days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Sex:

male/female

Dose descriptor:

LC0

Effect level:

11.05 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

7 h

Remarks on result:

other: Inhalation hazard test

Mortality:

No deaths observed when animals were exposed to an atmosphere saturated with the test substance.

Clinical signs:

other: Loss of pain reflex up to 4 hours after the exposure start, intermittent respiration during the first 8 minutes of exposure. No further adverse effects observed.

Body weight:

no data

Gross pathology:

No adverse effects observed.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

11 000 mg/m³ air

Quality of whole database:

well documented study reports and publications, sufficient for assessment

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

weight of evidence

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)

Deviations:

yes

Remarks:

occlusive instead of semiocclusive conditions, no details concerning clinical signs or necropsy findings

Principles of method if other than guideline:

acc. to Smyth HF et al. (1962) Am. Ind. Hyg. Assoc. J. 23, 95

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rabbit

Strain:

New Zealand White

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.5 - 3.5 kg

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: trunk
- Type of wrap if used: impervious plastic film


REMOVAL OF TEST SUBSTANCE
- Washing (if done): no data
- Time after start of exposure: 24 h

Duration of exposure:

24 h

Doses:

no data

No. of animals per sex per dose:

4

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days

Statistics:

LD50 value and its fiducial range are estimated by the method of Thompson (1947) using the Tables of Weil (1952)

Sex:

male

Dose descriptor:

LD50

Effect level:

ca. 3 216 mg/kg bw

Based on:

test mat.

95% CL:

2 373 - 4 350

Remarks on result:

other: calculated based on density = 0.81 g/cm3

Mortality:

Original value: LD50 = 3.97 mL/kg bw (95% CL: 2.93-5.37)

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

3 216 mg/kg bw

Quality of whole database:

reliable studies conducted similar to OECD Guideline, sufficient for assessment

Additional information

Acute toxicity

 

Oral route

Acute oral toxicity of 3-methylbutan-1-ol was evaluated in a study which was performed similar to the methods described in OECD guideline 401. Groups of 5 male and 5 female Sprague-Dawley rats received doses of 2150 and 5000 mg/kg bw 3-methylbutan-1-ol in carboxymethyl cellulose by gavage treatment. Up to 5 hours after treatment clinical symptoms including dyspnoea, apathy, abnormal position, staggering, erythrodermia and poor general state were observed in both dose groups. In both dose groups 1/5 females died, whereas all males survived until study termination. At necropsy, acute congestive hyperemia in the heart and cardiodilatation were observed in the deceased animals. The LD50 was estimated to be > 5000 mg/kg bw (BASF AG 1979).

Another oral toxicity study of 3-methylbutan-1-ol was conducted according to methods described by Smyth HF et al. (Am. Ind. Hyg. Assoc. J. 23, 95, 1962). Groups of 5 male and 5 female Carworth-Wistar rats received a logarithmic series of doses differing by a factor of two of 3-methylbutan-1-ol by gavage treatment. The animals were observed for 14 days. The LD50 value and its fiducial range were estimated by the method of Thompson (1947) using the tables of Weil (1952). The LD50 was estimated to be ca. 5726 mg/kg bw 95 % CL: 3856-8424; calculated based on density = 0.81 g/cm3) (Smyth 1969).

Acute oral toxicity of the read-across substance pentan-1-ol was evaluated in a study similar to OECD guideline 401. Groups of 5 male and 5 female Sprague-Dawley rats were dosed with approx. 162, 1296, 2592, 3240, 4050, 5184, 6480, and 8100 mg/kg bw pentan-1-ol in carboxymethyl cellulose by gavage. In the 2592 mg/kg bw and higher dose groups clinical signs including staggering, atonia, apathy, narcosis and tachypnea were noted. At the two low dose levels no mortalities occurred. In the higher dose groups at 2592, 3240, 4050 and 5184 mg/kg bw 3/10, 2/10, 8/10 and 9/10 animals were found dead within 24 hrs, respectively. In the two highest dose groups all animals died within one hour after administration. At necropsy, venous congestive hyperemia and acute cardiodilatation were observed in the deceased animals. The LD50 was estimated to be approx. 3645 mg/kg bw (BASF AG 1973)

Acute oral toxicity of the read-across substance, 2-methyl-1-butanol, was also evaluated similar to OECD guideline 401. Groups of 5 male and 5 female Sprague-Dawley rats received doses of 1470, 2150, 3160 and 5000 mg/kg bw 2-methyl-1-butanol as 14.7, 21.5, 31.6 and 50 % solution in carboxymethyl cellulose by gavage treatment. At 5000 and 3160 mg/kg bw 8/10 and 1/10 animals died within one day after administration, respectively. Clinical signs included dyspnoea, apathy, abnormal/lateral position, staggering, paresis/atonia, pain and corneal reflex absent, piloerection and poor general state. At necropsy, acute congestive hyperemia in the heart and cardiodilatation were detected in the deceased animals. Due to the observed mortality in the higher dose groups, the LD50 value of approx. 4172 mg/kg bw was estimated (BASF AG 1979).

A further study is available which was conducted with the read-across substance pentan-1-ol. Male Wistar rats were administered with approx. 3258, 6515 and 13030 mg/kg bw pentan-1-ol by gavage. Clinical signs of intoxication included unsteady gait, prostration, and heavy breathing. Gross pathology in animals that died included stomachs transparent, distended, injected, gas or fluid-filled; medullae of kidneys pink; intestines transparent or pink, injected, fluid-filled. Due to the observed mortality a LD50 of 4610 mg/kg bw was estimated (UCC 1978).

A study is available which was conducted with the read-across substance 2-methyl-1-butanol. 5 male albino rats were administered with approx. 1632, 3264 and 6528 mg/kg bw 2-methyl-1-butanol by gavage. Mortality was observed in all rats dosed with 6528 mg /kg bw within a day of dosing. One of 5 rats dosed with 3264 mg/kg bw died on the day of dosing. All other rats dosed with 3264 mg/kg bw as well as rats dosed with 1632 mg/kg bw survived the 14 day observation period. Surviving rats gained 36-60 g bw during the 14 day observation period. Gross pathology on the rats dosed with 6528 mg /kg bw. revealed congested or hemorrhaged lungs, mottled or chemically burned livers, spleens and stomachs, mottled or pale kidneys, congested adrenals and gastrointestinal tract irritation or hemorrhage. Due to the observed mortality a LD50 of 4015 mg/kg bw was estimated (95 % CL: 3044-5271; calculated based on rel. density = 0.816) (UCC 1959).

An oral toxicity study was conducted with the read-across substance pentanol, branched and linear. Each 5 male Carworth-Wistar rats were administered with 2520, 3160, 3980 and 5000 mg/kg bw pentanol, branched and linear in corn oil by gavage. The rats were prostrated at 5000 mg/kg bw and had tremors at 2500 mg/kg bw. Autopsies revealed congested or hemorrhaged lungs, mottled livers, gastrointestinal tract irritation and surface burning of the kidney and adrenal where they contacted the gastrointestinal tract. A LD50 of 3900 mg/kg bw was estimated (95 % CL: 3300-4500) (UCC 1955).

Another study with the read-across substance branched and linear pentanols (CAS 94624-12-1) was performed. In this study five male Sprague-Dawley rats per dose received a mixture of 75 % wt 1-Pentanol, 25 % wt 2-methyl-1-butanol, 1 % wt 3-methyl-1-butanol at doses of approx. 26.1 - 8155 mg/kg bw by gavage. After dosing, central nervous system depression and laboured respiration were noted and the recovery was completed by the second or third day. Due to observed mortality occurring within 24 hours, a LD50 of 2690 mg/kg bw was calculated (Scala & Burtis 1973).

In several further abstracts LD50 values in rats greater than 2000 mg/kg bw were confirmed. The LD50 in mice was reported as 3000 mg/kg bw, while no guinea pig died up to approx. 650 mg/kg bw. No further details are available.

As a conclusion, the acute oral toxicity of Pentanol is low.

 

Inhalation route

Acute inhalative toxicity of 3-methylbutan-1-ol was investigated in an inhalation hazard test (IHT) according in principle to the method described in the Annex of OECD TG 403 (1981), where three male and three female Sprague-Dawley rats were exposed to a saturated vapour atmosphere of 3-methylbutan-1-ol (whole body) for 7 hours (BASF AG 1979). The only clinical signs observed were intermittent respiration during the first few minutes of exposure and a loss of pain reflex up to 4 hours after start of the exposure. Otherwise, no mortality and no remarkable adverse effects were observed. Thus, the LC0 was 11.05 mg/L air based on the weight loss of the substance during the exposure period.

Another inhalative toxicity study (IHT) of 3-methylbutan-1-ol was conducted according to methods described by Smyth HF et al. (Am. Ind. Hyg. Assoc. J. 23, 95, 1962). 6 male and 6 female albino rats were exposed with the whole body to a concentrated vapour in air for 8 h. Afterwards animals were observed for 14 days. No mortality was detected. The LC0 was estimated at 10 mg/L air (calculated acc. to formula: vapour saturation (mg/L) = 0.0412 * vapour pressure (hPa) * molecular weight (g/mol)) (Smyth 1969). 

An additional acute inhalative toxicity study (Alarie assay) with 3-methylbutan-1-ol was conducted using 4 male Swiss Webster mice. The vapour-aerosol mixture was proposed with a concentration of 16.28 mg/L. Animals were exposed head only for 10 min. The RD 50 was estimated at 16.28 mg/L air (nominal) and at 4452 ppm (95 % CL: 2885-12459) (Kane 1980).  

Another study of 3-methylbutan-1-ol investigated the acute toxicity using an inhalation hazard test (Alarie assay). Mice were exposed via vapour in air. The RD 50 (50% decrease in respiratory rate) was estimated at 2.63 mg/L air (nominal) and the log(1/RD50) was -3.42 mg/m3 air (nominal) (Muller 1984).

Acute inhalative toxicity to the read-across substance pentan-1-ol was also examined in an inhalation hazard test (IHT) equivalent to the method described in the Annex of OECD TG 403 (1981), where three male and three female Sprague-Dawley rats were exposed (whole body) to a saturated atmosphere of pentan-1-ol vapours for 8 hours (BASF AG 1973). Since no mortality and no remarkable adverse effects were observed, the LC0 of 8.29 mg/L air could be calculated using the weight loss of the substance during the exposure period.

This is supported by another inhalation hazard test where no mortality was observed either, when six male Wistar rats were exposed for 8 hours to an atmosphere that was essentially saturated with pentan-1-ol vapours (UCC 1978).

An inhalation hazard test (IHT) according to the method described in the Annex of OECD TG 403 (1981) was also conducted to assess the acute inhalative toxicity to 2-methylbutan-1-ol. Three male and three female Sprague-Dawley rats were exposed (whole body) to a saturated vapour atmosphere of 2-methyl-1-butan-1-ol for 7 hours. Since no mortality and no remarkable adverse effects were observed, the experiment was repeated once. A nominal LC0 of 12.28–16.61 mg/L air could be calculated using the weight loss of the substance during the exposure period (BASF AG 1979).

Another test using 2-methylbutan-1-ol was conducted (UCC 1959). A group of 6 CFN female rats were exposed with the whole body to a concentration of 3427 ppm (=12.53 mg/L) of the vapour in air for 8 hours. During the 14 day observation period no mortality was detected. Two rats were prostrate after 6 hours and 3 were anesthetized after 8 hours. The others had poor coordination of body movements. All survived and gained weight during the observation period. Therefore a LC0 was established at 12.53 mg/L air (nominal) and 3427 ppm.

An inhalation hazard test is also available for branched and linear pentanols (CAS 94624-12-1) (UCC 1955). When groups of 6 male rats were exposed to an atmosphere saturated with vapours of a mixture of pentan-1-ol and 2-methylbutan-1-ol for 8 hours, no mortality was observed. The only notable response was light anesthesia after 1.5 hours in exposure. All rats were active a few seconds after cessation of the exposure.

For 3-methylbutan-1-ol no animal studies including inhalation exposure to an aerosol are available, but valid aerosol studies in rats, mice and guinea pigs conducted with an isomer mixture equivalent to pentanol, branched and linear (CAS No. 94624-12-1) are taken into consideration by read-across.

Groups of 10 Wistar rats, 10 Swiss mice and 10 English Short Hair guinea pigs were exposed to an aerosol of 14 mg/L amyl alcohol consisting of 75 % wt pentanol-1-ol, 25 % wt 2-methyl-1-butanol and 1 % wt 3-methyl-1-butanol (Scala & Burtis 1973). As a consequence of mortality (2/10), the LC50 of > 14 mg/L air was determined in rats, whereas in mice the LC50 was < 14 mg/L air (7/10). Since in the study with guinea pigs no mortality occurred (0/10), the effect level for this species was LC0 = 14 mg/L air. Clinical signs included prostration and irritation of mucous membranes of the eyes, nose, throat and respiratory passage. Histological examination of trachea, lung, liver, and kidney from the exposed animals revealed an increase in the size of the deep proximal convoluted tubules associated with an increased size of the epithelial cells lining the tubules. Pulmonary oedema was noted in the mice.

An additional acute inhalative toxicity study (Alarie assay) with pentan-1-ol was conducted using 4 male Swiss Webster mice. The vapour-aerosol mixture was proposed with a concentration of 14.8 mg/L. Animals were exposed head only for 10 min. The RD 50 was estimated at 14.8 mg/L air (nominal) and at 4039 ppm (95 % CL: 3113-6033) (Kane 1980).  

Another study of pentan-1-ol investigated the acute toxicity using an inhalation hazard test (Alarie assay). Mice were exposed via vapour in air. The RD 50 (50% decrease in respiratory rate) was estimated at 2.2 mg/L air (nominal) and the log(1/RD50) was -3.34 mg/m3 air (nominal) (Muller 1984). 

A study with pentan-1-ol was conducted according to ASTM guideline (ASTM (1984) Standard test method for estimating sensory irritancy of airborne chemicals, American Society for Testing and Materials, Philadelphia, Designation: E981-84.) using male CF-1 mice. The animals were exposed head only to the unchanged vapour for 30 min. The RD 50 was estimated at 10.97 mg/L air (nominal) and at 3000 ppm (Hansen 1994).

In addition, several of these studies where the sensory or respiratory tract irritation of mice was investigated after vapour inhalation exposure (Alarie assays) are discussed in additional detail in the chapter “Irritation. Respiratory tract”.

Taken together, no mortality was observed in acute inhalation toxicity studies conducted with vapours of 3-methylbutan-1-ol or the read across substances. Only one category member (CAS 94624-12-1) was tested as an aerosol, revealing an LC50 value below 14 mg/L in mice, but above 14 mg/L in rats and guinea pigs.

 

Dermal route

Acute dermal toxicity of 3-methylbutan-1-ol was investigated in a study where four male New Zealand White rabbits received an application of 3-methylbutan-1-ol occluded by an impervious plastic film for 24 hours (Smyth et al.1969). As a result, a LD50 of 3.97 mL/kg bw was reported, which corresponds to approx. 3216 mg/kg bw. No data concerning clinical signs of intoxication or necropsy findings were given.

For testing the acute dermal toxicity of the read-across substance pentan-1-ol, four male albino rabbits received a dermal application of approx. 1620 and 3240 mg/kg bw and two received an application of approx. 6480 mg/kg bw under occlusive conditions for 24 hours. The testing procedure was comparable to the methods described in OECD TG 402 with one deviation, occlusive instead of semi-occlusive application conditions. At 1620 mg/kg bw no mortality was observed, while all animals at the higher dose levels died. Clinical signs included ataxia and lethargy. At necropsy the following findings were recorded: at 3240 and 6480 mg/kg bw, livers with tan mottling, spleens with dark purple mottling, and kidneys colored red or brown were observed in animals that died. At 1620 mg/kg bw, livers were mottled dark red. No other gross pathological changes were observed. Since all animals of the 3240 and 6480 mg/kg bw dose groups died within the first 48 hours after application, a LD50 of 2292 mg/kg bw was determined (UCC 1978).

Acute dermal toxicity of 2-methylbutan-1-ol was tested in a study, where 4 male New Zealand White rabbits received a dermal application of approx. 2040 and 4080 mg/kg bw 2-methylbutan-1-ol under occlusive conditions for 24 hours. The testing procedure was comparable to the methods described in OECD TG 402 with one deviation, occlusive instead of semi-occlusive application conditions. There was no mortality in rabbits dosed dermally with 2040 mg/kg bw. At 4080 mg/kg bw, all animals died. One rabbit died on the day of test material application and the remaining died on days 1, 3 or 4 after application. Local skin findings included erythema, edema or necrosis of the skin at the application site. No signs of systemic toxicity were recorded. At necropsy, deceased animals showed hemorrhage under the skin, mottled or pale livers and kidneys and lung hemorrhage. The LD50 was determined to be approx. 2889 mg/kg bw (UCC 1959).

Additionally, for testing branched and linear pentanols (CAS 94624-12-1), 4 male New Zealand white rabbits received a dermal application of approx. 2055, 4078, and 8155 mg/kg bw under occlusive conditions for 24 hours. All animals dosed with 8155 mg/kg bw died within 1 day post dosing. Two of four rabbits dosed with 4078 mg/kg bw died during the dosing period. At the low dose level of 2055 mg/kg bw, one rabbit died two days after dosing. At necropsy the following findings were recorded: necrosis and erythema of the exposed skin, hemorrhagic lungs, livers pale and mottled and kidneys pale with pitted surfaces. There was some subcutaneous hemorrhage. Under the conditions of this study, a LD50 of 3662 mg/kg bw was determined (UCC 1959).

Another study with the read-across substance branched and linear pentanols was performed. In this study doses of 200, 500, 794 and 3160 mg/kg bw were applied as an unchanged occlusive patch on 4 albino rabbits for 24 h. After dosing, central nervous system depression with labored respiration, ataxia and sprawled limbs were noted and the recovery occurred in 4 to 48 hours after the exposure began. In addition signs of irritation including severe erythema, moderate edema, atonia, blanching, desquamation, necrosis and eschar were observed. Most signs persisted till termination of the 14 day observation period. An LD50 of > 3160 mg/kg bw was determined (Scala & Burtis 1973).

As a conclusion, the dermal LD50 values are greater than 2000 mg/kg bw for all members of the category. A detailed read across justification is attached in IUCLID chapter 13. 

 

Other routes

An assessment of the acute toxicity of 3-methylbutan-1-ol after i.p. injection was done. A dose of 700 mg/kg bw was administered to 5 male and female NMRI mice. A mortality of 3 males and 2 females within the first 7 days and the remaining 3 females within 14 days was observed. Clinical signs were dyspnoe, apathy, abnormal position, atony, paresis of forelimbs, staggering, tremor, erythrodermia, exsiccosis, fuzzy fur and poor general state. The treated animals lost weight during the 3-7 days after treatment, but showed normal weight gain afterwards. Gross pathology of survivors showed no abnormalities while one animals that died during the study presented with kidney damage. An LD50 value of ca. 700 mg/kg bw was derived (BASF AG 1979).

Using 3-methylbutan-1-ol an intravenous study was conducted in female white breed H mice. The derived LD50 was 2.64 mmol/kg bw and ca. 233 mg/kg bw (Chvapil 1962).

For the read-across substance pentan-1-ol a study assessing the acute toxicity of the test substance applied intraperitoneally was done. Doses of 0.2, 0.4, 0.8, 1.6 mL/kg bw (corresponding to ca. 163, 326, 652, 1304 mg/kg bw assuming a density of 0.815 g/mL) were administered to 5 NMRI mice per dose level. Mortality occurred from the 326 mg/kg bw dose group onwards. An LD50 value of ca. 326 mg/kg bw was derived (BASF AG 1973).

In addition an intravenous study with the read-across substance pentan-1-ol was conducted in female white breed H mice. The derived LD50 was 2.09 mmol/kg bw and ca. 184 mg/kg bw (Chvapil 1962). 

Justification for selection of acute toxicity – oral endpoint
Several studies are available (including read across studies) and were used to evaluate the acute toxicity after oral administration in a weight of evidence approach.

Justification for selection of acute toxicity – inhalation endpoint
Several studies are available and were used to evaluate the acute toxicity after inhalation in a weight of evidence approach.

Justification for selection of acute toxicity – dermal endpoint
Several studies are available and were used to evaluate the acute toxicity after oral administration in a weight of evidence approach.

Justification for classification or non-classification

The available data are considered reliable and suitable for classification purposes under Regulation (EC) No 1272/2008 (CLP).

LD50 values after oral and dermal exposure were above 2000 mg/kg bw. No mortality occurred after exposure for 7 or 8h to the saturated vapour concentration (approx. 8 – 16 mg/L depending on the category member, app. 11mg/L for 3 -methylbutanol). Aerosol exposure to the read across substance CAS 94624 -12 -1 resulted in LC50 values above 14 mg/L for rats and guinea pigs. 7 of 10 mice died at this concentration, but which is well above the upper limit for classification.

Consequently, based on the available data, no classification for acute oral, dermal, or inhalation toxicity is required. Nevertheless, pentanols isomers are legally classified under Regulation (EC) No 1272/2008, as amended for the seventh time in Regulation (EC) No 1297/2014, for acute inhalation toxicity category 4 and labeled with H332 (Harmful if inhaled).