Propan-2-thiol

Extinguish with dry chemicals, alcohol foam, or carbon dioxide. Water may be ineffective on fire. Cool exposed containers with water.

If material /is/ on fire or involved in /a/ fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may spread fire. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide. /Butyl mercaptan/

Evacuation: If fire becomes uncontrollable or container is exposed to direct flame-consider evacuation of one-third (1/3) mile radius. If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location and weather conditions.

... Materials which are toxic as stored /such as isopropyl mercaptan/ or which can decompose into toxic components ... should be stored in a cool, well ventilated place, out of the direct rays of the sun, away from areas of high fire hazard, and should be periodically inspected.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Ethyl mercaptan is a waste chemical stream constituent which may be subjected to ultimate disposal by controlled incineration (2,000 °F) followed by scrubbing with a caustic solution.

Incineration ... : Incinerate scrap material under controlled conditions using afterburner and a scrubber to neutralize sulfur dioxide ... .

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Personnel protection: Avoid breathing vapors. Keep upwind. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Butyl Mercaptan/

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to disperse vapors and dilute standing pools of liquid.

Open flames and other ignition sources should be excluded from areas where thiols, especially the more volatile ones, are used. Emergency procedures and routine work practices should emphasize proper handling, containment of spills... The primary purpose of control measures is to reduce the potential for inhalation or skin contact with thiols, with special emphasis on the eyes. Whenever feasible, control at the source of exposure should be implemented. This may involve enclosure of the operation and/or the use of local exhaust ventilation. /Thiols/

For more Preventive Measures (Complete) data for ISOPROPYL MERCAPTAN (10 total), please visit the HSDB record page.

Self-contained breathing apparatus; goggles or face shield; rubber gloves (USCG, 1999)

Self-contained breathing apparatus; goggles or face shield; rubber gloves.

Plastic gloves; goggles or face shield.

Where ... engineering controls are not sufficient to reduce airborne concentrations to acceptable levels respirators may be necessary to prevent pulmonary irritation and systemic effects. At low concentrations (less than 5 ppm) a chemical cartridge respirator with a half-mask facepiece and organic vapor cartridges can be used. At high concentrations, supplied air respirators, with a full facepiece, are necessary. /Thiols/

Chemical protective clothing should be selected after utilizing available performance data, consulting with the manufacturer, and then evaluating the clothing under actual use conditions. Workers should be provided with and required to use chemical protective clothing, gloves, face shield (8-inch minimum), and other appropriate protective clothing necessary to prevent skin contact with n-butyl mercaptan. Workers should be provided with and required to use splashproof safety goggles where ethyl mercaptan may come in contact with the eyes.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a structure estimation method(2), indicates that isopropyl mercaptan is expected to have very high mobility in soil(SRC). Volatilization of isopropyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.6X10-3 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Isopropyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 277 mm Hg(4). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a structure estimation method(2), indicates that isopropyl mercaptan is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 4.6X10-3 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 hours and 3.5 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 4(SRC), from an estimated log Kow of 1.7(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2005).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isopropyl mercaptan, which has a vapor pressure of 277 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase isopropyl mercaptan is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 8 hours(SRC), calculated from its rate constant of 4.10X-11 cu cm/molecule-sec at 25 °C(3). Isopropyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of isopropyl mercaptan can be estimated to be 35(SRC). According to a classification scheme(2), this estimated Koc value suggests that isopropyl mercaptan is expected to have very high mobility in soil.

Isopropyl mercaptan has been qualitatively detected in crude oil samples(1,2). The occurrence of small amounts of alkyl mercaptans in crude oil is believed to result from microbial action on elemental sulfur(2). Mercaptans are formed naturally in biological processes and exist in all living systems(2,3); the lower alkyl mercaptans occur in manure gas from domestic animal pens(2) and have obnoxious odors at low concns(2-4).

/SIGNS AND SYMPTOMS/ Strong, offensive smell of mercaptans can cause headache and nausea. High concentrations of their vapors in atmosphere can produce unconsciousness with cyanosis, a sense of coldness at extremities and quickening of pulse ...pulmonary edema. /Mercaptans/

/SIGNS AND SYMPTOMS/ In the manufacture of rubber, irritant contact dermatitis may occur from a variety of acids, alkalies, detergents, and solvents used in the process. Allergic contact dermatitis occurs not infrequently and is almost always due to an organic accelerator or antioxidant. /Mercapto compounds/

An estimated BCF of 4 was calculated for isopropyl mercaptan(SRC), using an estimated log Kow of 1.7(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for isopropyl mercaptan is estimated as 4.6X10-3 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that isopropyl mercaptan is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 3 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 3.5 days(SRC). Isopropyl mercaptan's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Isopropyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 277 mm Hg(3).

/LABORATORY ANIMALS: Acute Exposure/ Clinical signs /in rats given oral doses of 2000-5000 mg/kg/ included hypotonia, ataxia, loss of righting reflex, and body weight loss.

/LABORATORY ANIMALS: Acute Exposure/ Liquid isopropyl mercaptan produced slight irritation of the skin and eyes of rabbits, which recovered within 48 hr. Head-only exposure of mice to a concentration of 4362 ppm for two 1-min periods did not produce upper airway irritation as measured by individual plethysmographs.

/LABORATORY ANIMALS: Acute Exposure/ A ... 4 hour inhalation study was conducted in the rat at a concentration of 3899 ppm. Clinical signs noted during exposure included hyperactivity and ataxia, labored respiration, prostration, and squinted eyes. Reduced body weights where noted for 4 to 7 days postexposure. No deaths occured and no gross pathological changes were noted at necropsy.

/LABORATORY ANIMALS: Acute Exposure/ Four hour acute inhalation studies in the rat showed ... signs ... during exposure were typical of ocular, nasal, and pulmonary irritation. Weight gain in the exposed rats was slightly reduced 2 to 5 days.

/ALTERNATIVE IN VITRO TESTS/ L-2-Oxo-3-(2-mercaptoethyl)-5-phenylimidazolidine (OMPI) a sulfhydryl metabolite of levamisole, unlike the parent compound, is shown to interfere with the morphological and functional integrity of microtubules in cultured cells at high concentrations (1.6-10(-4) M). Lower concentrations do not affect the cell morphology, viability or growth rate in any appreciable way. Both levamisole and OMPI, at low concentrations (10(-5)-10(-6) m), markedly enhance the antimicrotubular effect of mercaptoethanol. High concentrations of OMPI (+ or - 10(-4) M) inhibit the self-assembly of microtubules in a cell free system. Low concentrations (+ or - 10(-6) M) markedly enhance the polymerization rate of tubulin. Levamisole has no effect on tubulin polymerization. The effects of OMPI on microtubules in cells and in the polymerization system can be reversed by reduced glutathione, cysteine and dithiothreitol. The data indicate that OMPI interacts in a biphasic manner with microtubule formation probably through interaction with critical SH-groups on the tubulin molecule. It seems of interest to further investigate the hypothesis that the immunomodulating properties of levamisole are at least partially due to the formation of its metabolite (OMPI) which could enhance microtubule integrity and function in leukocytes.

Rate constants for the vapor-phase reaction of isopropyl mercaptan with photochemically-produced hydroxyl radicals have been reported as 4.20X10-11, 3.9X10-11, and 4.59X10-11 cu cm/molecule-sec at 25 °C(1-3). These values correspond to an atmospheric half-life of about 8 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The hydroxyl radical reaction proceeds primarily through OH addition to the sulfur(1); based upon chamber experiments with similar sulfur compounds(4), the reaction products may include isopropylsulfonic acid(SRC). Isopropyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(5). Isopropyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4,715 workers are potentially exposed to isopropyl mercaptan in the USA(1). Occupational exposure to isopropyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where isopropyl mercaptan is produced or used(SRC). Use data suggest that the general population may be exposed to isopropyl mercaptan via inhalation of ambient air in the vicinity of natural gas refineries and operations(SRC).