1-butanol

71-36-3

1-butanol is used as an ingredient in perfumes and flavours
(Mellan 1950) and of: hop, lipid-free protein from egg yolk
(Meslar & White 1978), natural flavouring materials and
vegetable oils, phenols, and oligosaccharides from plant tissue
(Sodini & Canella 1977), and as a solvent in removing pigments
from moist curd leaf protein concentrate (Bray & Humbries
1978). 1-butanol is also used as: an extractant in the 
manufacture of antibiotics, hormones, and vitamins 
(Mellan 1950, Doolittle 1954, Yamazaki & Kato 1978), 
and of rhenium (Gukosyan et al.1979); 
a solvent for paints, coatings, natural resins, gums,
synthetic resins, dyes, alkaloids, and camphor (Mellan 1959,
Doolittle 1954); a cleanser for moulded contact lenses
(Mitazani et al. 1978); an intermediate in the
manufacture of butyl acetate, dibutyl phthalate, and dibutyl
sebacate (Mellan 1950, Doolittle 1954) as well as of the esters
of herbicides (Monich 1968).

Other miscellaneous applications of 1-butanol are as a swelling
agent in textiles, as a component of brake fluids, cleaning
formulations, degreasers (Monich 1968, Sitanov et al.1979), and
repellents (Zaikina et al.1978); and as a component of ore
flotation agents (Monich 1968), 
of protective coatings for glass objects (Artigas Gimenez
et al. 1979) and of wood-treating systems (Amundsen et al.
1979).

Mixed with xylene, it is used to produce a glass
substitute (Ferri 1979). 
It is also used as an additive to
increase the fineness of ground cement (Tavlinova & Dovyborova
1979) and as a solvent in the purification of polyolefins
(Takeuchi et al. 1978).

It may be liberated during photographic processing operations.

A further use of 1-butanol is as a flavouring agent in butter,
cream, fruit, liquor, rum, and whisky. 
Other foods in which it
is used include: Beverages, ice cream and ices, candy, baked
goods, cordials and cream (Hall & Oser 1965).

Colourless liquid.

Characteristic; rancid sweet.

Hedonic tone: neutral to pleasant.

Odour threshold approximately 3.078 mg/m3.

At a concentration of 20 mg/l, butanol gives a strong
unpleasant odour to drinking water. 
The odour threshold is 1
mg/l (Nazarenko 1969).

Threshold for unadapted panellists: 50 ppm
Threshold after adaption with pure odourant: 10000 ppm
Distinct odour: 48 mg/m3 = 16 ppm
(Verschueren 1983).

In water:
20 % of the population still able to detect odour at 1.5 ppm
10 % of the population still able to detect odour at 1.2 ppm
of the population still able to detect odour at 0.44 ppm
0.1 % of the population still able to detect odour at 0.16 ppm
(Lillard et al. 1975).

Quality: rancid, sweet
Hedonic tone: neutral to unpleasant
Threshold odour concentration:
absolute: 0.30 ppm
50 % recognition: 1.0 ppm
100 % recognition: 2.0 ppm
Odour index 100 % recognition: 2 630
(Hellman & Small 1974)

74.12

Relative volatility (nBuAc=1) = 0.47

Using a measured log octanol/water partition coefficient of
0.88, a soil sorption coefficient (Koc) of 71.6 was estimated 
(Lyman et al. 1982).

A Koc of this magnitude suggests that n-butanol will be
moderately to highly mobile in the soil (Kenaga 1980).

Photooxidation half-life in air:
8.8hr - 87.7hr,
based upon measured rate data for the vapor phase reaction
with hydroxyl radicals in air (Howard 1991).

Photooxidation half-life in water:
108d - 11.9yr,
based upon measured rate data for hydroxyl radicals in aqueous
solution (Howard 1991).

Aerobic half-life:
24hr - 168hr,
scientific judgement based upon unacclimated freshwater grab 
sample data (Howard 1991).

Anaerobic half-life:
4d - 54d,
scientific judgement based upon acclimated anaerobic screening 
test data (Howard 1991).

When released to soil n-butanol is expected to leach to ground
water or to biodegrade. 
Volatilization from the soil surface
may also occur (Howard 1990).

In water, n-butanol is expected to biodegrade. 
Volatilization
from the water surface is expected to occur with estimated
half-lives of 2.4 hr, 3.9 hr and 125.9 days in streams, rivers
and lakes (Lyman et al. 1982)

Impact on biodegradation processes:
50 % inhibition of NH3 oxidation in Nitrosomonas at 8200 mg/l
(Verschueren 1983).

A 3 ppm solution of n-butanol was incubated in river water at
18 - 19 °C exerted a biological oxygen demand (BOD) of about
4.5 ppm after about 4 days (Hammerton 1955).

After 5 days 33% of the theoretical BOD was exerted in a
solution of n-butanol containing an inoculum from polluted
surface water (Dore et al. 1975).

In a batch system, n-butanol was dissolved to give a
concentration corresponding to a chemical oxygen demand (COD)
of 200 mg/l (Pitter 1976)

Sufficient adapted activated sludge was added to make the dry
matter of the inoculum 100 mg/l and the system was incubated at
20°C. 
Under these conditions a total of 98.9% of the initial
n-butanol was removed at a rate of 84.0 mg COD/g hr (Hammerton 
1955).

After 5 days incubation at 20°C, 66% of the theoretical oxygen
demand had been exerted in a BOD test (Bridie 1979).

1-butanol does not bioaccumulate (Chiou et al. 1977).

1-butanol is readily absorbed through the skin, lungs, and
gastrointestinal tract. 
In animals, 1-butanol is rapidly
metabolized by alcohol dehydrogenase to the corresponding acid,
via the aldehyde, and to carbon dioxide, which is the major
metabolite. 1-butanol is slightly toxic to mammals, markedly
irritating to the eyes and moderately irritating to the skin.

The primary effects from exposure to vapour for short periods
are various levels of irritation of the mucous membranes and
central nervous system depression. 
Its potency for intoxication
is approximately 6 times that of ethanol. 
A variety of
investigations have indicated non-specific membrane effects of
1-butanol. 
Effects of repeated inhalation exposure in animals
include pathological changes in the lungs, degenerative lesions
in the liver and kidneys, and narcosis. 
However, from the
animal studies available, it is not possible to determine a
no-observed-adverse-effect- level. 1-butanol has been found to
be non-mutagenic. 
No adequate data are available on
carcinogenicity, teratogenicity, or effects on reproduction
(WHO 1987).

Mouse: inhalation: no effect: 1650 ppm, 420 min (Patty 1967).

In man, 1-butanol, in the liquid or vapour phase can cause
moderate skin irritation and severe eye irritation manifested
as a burning sensation, lachrymation, blurring of vision, and
photophobia. 
Ingestion of the liquid or inhalation of the
vapour may result in headache, drowsiness, and narcosis. 
The
occurance of vertigo under conditions of severe and prolonged
exposure to vapour mixtures of 1-butanol and isobutanol has
been reported. 
From this study it was not possible to attribute
to vertigo to a single cause. 
The symptoms were reversible when
exposure ceased.

The minimal information available suggest that occupational
human exposure to air concentrations below 307.8 mg/m3 is not
associated with any adverse symptoms. 
However, studies on human
volunteers indicate that the light sensitivity of dark-adapted
eyes and electrical activity of the brain may be influenced by
air concentrations as low as 0.092 mg/m3.

Man: mild irritation of nose, throat, and eyes: 25 ppm
pronounced irritation : 50 ppm 
(Patty 1967).

Mutagenicity in the Salmonella test: none:
< 0.0005 revertant colonies/nmol
< 70 revertant colonies at 10 mg/plate
(McCann et al. 1975).

Threshold for narcosis: 2820 mg/l, Rana sp (Münch 1972).

Seed germination in lettuce (Lactuca sativa) was inhibited by
50 % at a concentration of 1-butanol of 390 mg/l
(Reynolds 1977).

Seed germination in cucumber (Cucumis sativus) was inhibited at
2500 mg/l (Smith & Siegal 1975).

1-butanol had an antisenescence effects on the leaves of oat
seedlings (Avena sativa). 
It both maintained chlorophyll levels
and prevented proteolysis in the dark (Satler & Thimann 1980).

Table 1. 
Toxicity data for microorganisms (WHO 1987).
_______________________________________________________________
Species       Conc.mg/l     Parameter      Reference
---------------------------------------------------------------
Protozoa
Uronema                     NOEC 20hr      Bringmann & Kühn
parduczi          8         total biomass  1981
(ciliate)

Chilomonas                  NOEC 48hr         - " -
paramaecium      28         total biomass
(flagellate)

Entosiphon
sulcatum         55         NOEC 72hr         - " -
(flagellate)                total biomass

Bacteria
Pseudomonas                 NOEC 16hr         - " -
putida          650         total biomass

Bacillus                    EC50              Yasuda-Yasaki et
subtilis       1258         spore germination al. 1978

               7400          no inhibition of    Chou et al.
                             degradation by      1978
                             methane culture
                             on acetate substrate
---------------------------------------------------------------

Toxicity threshold (cell multiplication inhibition test):
Bacteria (Pseudomonas putida): 650 mg/l
(Bringmann & Kühn 1980a)

31% - 99%,
based upon % degraded under acclimated aerobic semi-continuous 
and continuous flow conditions (Howard 1991).

At background concentrations likely to occur in the
environment, 1-butanol is not directly toxic for fish,
amphibia, or crustacea and is practically non toxic for algae.

Some protozoa are slightly sensitive to 1-butanol (WHO 1987).

Toxicity threshold (cell multiplication inhibition test):
Algae (Microcystis  aeruginosa): 100 mg/l
(Bringmann & Kühn 1976)

Green algae (Scenedesmus quadricauda): 875 mg/l
Protozoa (Entosiphon sulcatum): 55 mg/l
Protozoa (Uronema parduczi): 8.0 mg/l
(Bringmann & Kühn 1980a)

Algae (Chlorella pyrenoidosa: toxic: 8500 mg/l (Jones 1971).

1-butanol should be managed in the environment as a slightly
toxic compound. 
It poses an indirect hazard for the aquatic
environment, because it is readily biodegradable, which may
lead to oxygen depletion (WHO 1987).