Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 205-289-9
CAS number: 137-32-6
oral:All the LD50 values of the test substance and category members were found to be greater than 2000 mg/kg bw.inhalation:No mortalities occured when 2-methylbutan-1-ol or the read-across substances were applied as vapour. In a study conducted on a read-across substance (CAS 94624-12-1), which was applied as an aerosol, the LC50 in mice was found to be < 14 mg/L, but greater than 14mg/L for rats and guinea pigs.dermal:All the dermal LD50 value were found to be greater than 2000 mg/kg bw.
Acute oral toxicity of 2-methyl-1-butanol
was 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. 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).
Another study is available which was
conducted with 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).
Acute oral toxicity of the read-across
substance 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).
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 hours, 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
Another oral toxicity study of the
read-across substance 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).
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).
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 of greater 2000 mg/kg bw in rats 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.
An inhalation hazard test (IHT) according to
the method described in the Annex of OECD TG 403 (1981) was 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-butanol 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.
Acute inhalative toxicity of the read-across
substance 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.
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 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.
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).
For 2-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).
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).
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
2-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.
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).
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
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
Acute dermal toxicity of the read-across
substance 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.
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 path
on 4 albino 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.
An assessment of the acute toxicity of
2-methylbutan-1-ol after i.p. injection was done. Doses of 200, 700 and
2000 mg/kg bw was administered to 5 male and female NMRI mice. A
mortality of all animals treated with 2000 mg/kg bw was observed within
1 h after treatment. After treatment with 700 mg/kg bw 3 males and 4
females died within the first 7 days and the remaining 2 males within 14
days. No mortality was observed after treatment with 200 mg/kg bw. 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 some animals that
died during the study presented with intraabdominal agglutination. An
LD50 value of ca. > 200 - < 700 mg/kg bw was derived (BASF AG 1979).
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 and 1.6 mL/kg bw
(corresponding to ca. 163, 326, 652 and 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
The available data are considered reliable
and suitable for classification purposes under Regulation (EC) No
LD50 values after oral and dermal exposure
were above 2000mg/kg. No mortality occured after exposure for 7 or 8h to
the saturated vapour concentration (app. 8 - 16mg/L depending on the category
member, app. 12.5 for 2 -methylbutanol). Aerosol exposure to the read
across substance CAS 94624 -12 -1 resulted in LC50 values above 14mg/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, Pentanol 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).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Sellel veebilehel kasutatakse küpsiseid, et tagada lehe parim kasutus.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again