Butyl isocyanate

99.13

99.13

203-862-8

XM89T89J3W

1642

2485

DTXSID6026872

Colorless liquid

2929109000

29.4

2.26 (est)

Colorless Liquid

0.9 g/cm³

<-70 °C

115 °C

64 °F

1.429

Solubility in water: reaction

2-8°C

10.6 mm Hg ( 20 °C)

3 (vs air)

Oral-rat LD50: 600 mg/kg; Oral-Mouse LD50: 150 mg/kg

Flammable; thermal decomposition emits toxic nitrogen oxide fumes

vol% in air: 1.30

Henry's Law constant = 2.2X10-3 atm-cu m/mol at 25 °C (est)

Flammable liquid|Liquid molar volume = 0.112992 cu m/kmol|Hydroxyl radical reaction rate constant = 3.9X10-12 cu cm/molecule-sec at 25 °C (est)

Highly flammable. Extremely slow decomposition by water. Less dense than water and insoluble in water.

Isocyanates and Isothiocyanates

Highly Flammable

Isocyanates and thioisocyanates are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence [Wischmeyer 1969].

425 °C

The vapour mixes well with air, explosive mixtures are easily formed.

I

6.1(a)

UN 2485 6.1/PG 1

1

11-21/22-26-34-37-42/43

23-26-28-36/37/39-45

NQ8250000

F,T+

Treasury is ventilated, low temperature and dry; stored and transported separately from oxidant

Explosive when mixed with air

P210-P260-P280-P284-P305 + P351 + P338-P310

H225-H302-H311-H314-H330-H334

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.

European Chemicals Bureau; IUCLID Dataset, Butyl isocyanate (CAS No. 111-36-4) (2000 CD-ROM edition). Provides information on usage patterns, toxicology, and environmental effects supplied by industry to the European Union. Available from the database query page: http://ecb.jrc.it/esis/esis.php as of October 19. 2006.

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. (ERG, 2016)|Highly flammable. Heating will cause rise in pressure with risk of bursting. Vapour/air mixtures are explosive.|Flammable - 3rd degree, Reactive - 2nd degree

|Danger|H224 (21.05%): Extremely flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P284, P285, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P304+P341, P305+P351+P338, P310, P312, P320, P321, P322, P330, P342+P311, P361, P363, P370+P378, P403+P233, P403+P235, P405, and P501|Aggregated GHS information provided by 77 companies from 9 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H225: Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P272, P273, P280, P284, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P307+P311, P310, P320, P321, P330, P333+P313, P363, P370+P378, P403+P233, P403+P235, P405, and P501

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 2485 datasheet. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. A vapor-suppressing foam may be used to reduce vapors. FOR CHLOROSILANES, use AFFF alcohol-resistant medium-expansion foam to reduce vapors. DO NOT GET WATER on spilled substance or inside containers. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Prevent entry into waterways, sewers, basements or confined areas. SMALL SPILL: Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. (ERG, 2016)

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)|Personnel protection: ... Wear positive pressure self-contained breathing apparatus. ... Wear appropriate chemical protective gloves, boots and goggles.|Vapor Concentration: 0.2 ppm or less: Any supplied-air respirator or any self-contained breathing apparatus. 1 ppm or less: Any supplied-air respirator with a full facepiece, helmet, or hood or any self-contained breathing apparatus with a full facepiece. A type C supplied air respirator operated in a pressure-demand or other positive pressure or continuous flow mode. 20 ppm or less: A type C supplied-air respirator with a full facepiece operated in pressure-demand or other positive pressure mode or with a full facepiece, helmet, or hood operated in continuous-flow mode. Greater than 20 ppm or entry and escape from unknown concentrations: Self-contained breathing apparatus with a full facepiece operated in a pressure-demand or other positive pressure mode or a combination respirator which includes a type C supplied-air respirator with a full facepiece operated in pressure-demand or other positive pressure or continuous-flow mode and an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive pressure mode. Escape: Any escape self-contained breathing apparatus. /Methyl isocyanate/

Explosive limits , vol% in air: 1.3-10

Persons involved in fighting fires should wear a self-contained breathing apparatus with a full facepiece operated in a pressure-demand or other positive pressure mode. ... /Methyl isocyanate/|If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped or safely confined. 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 foam, dry chemical, or carbon dioxide.|Evacuation: If fire becomes uncontrollable or container is exposed to direct flame - consider evacuation of one-third (1/3) mile radius.

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 knock-down vapors.|Personnel protection: Avoid breathing vapors. Keep upwind. ... Avoid bodily contact with the material. ... 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. If contact with the material anticipated, wear appropriate chemical protective clothing.|Evacuation: If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location and weather conditions.|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.

If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY.|/GUIDE 155: SUBSTANCES - TOXIC and/or CORROSIVE (Flammable/Water-Sensitive)/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.|/GUIDE 155: SUBSTANCES - TOXIC and/or CORROSIVE (Flammable/Water-Sensitive)/ Health: TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.|/GUIDE 155: SUBSTANCES - TOXIC and/or CORROSIVE (Flammable/Water-Sensitive)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.|For more DOT Emergency Guidelines (Complete) data for N-BUTYL ISOCYANATE (9 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Strong irritant to eyes and skin.|Isocyanates are irritating to the skin and the mucous membranes. Eye affections are less common and, although lacrimation is often found. /Isocyanates/

Evacuate danger area! Ventilation. Remove all ignition sources. Personal protection: gas-tight chemical protection suit including self-contained breathing apparatus. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer. Do NOT let this chemical enter the environment.

Fireproof. Separated from strong oxidants and food and feedstuffs. Cool. See Chemical Dangers. Store in an area without drain or sewer access.

A harmful contamination of the air will be reached quickly on evaporation of this substance at 20 °C.

The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause lung oedema.

Repeated or prolonged contact may cause skin sensitization.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting.

AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety goggles or eye protection in combination with breathing protection.

| 3 - Materials that, under emergency conditions, can cause serious or permanent injury.| 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions.| 2 - Materials that readily undergo violent chemical changes at elevated temperatures and pressures.|W - No water: Materials that react violently or explosively with water.

highly toxic

IDENTIFICATION AND USE: N-Butyl isocyanate is a colorless flammable liquid, and It is soluble in water. It is used as a reagent in organic synthesis; used as intermediates in production of carbamate, and urea insecticides, and fungicides. It is also used in the production of sulfonyl urea antidiabetic drugs. HUMAN EXPOSURE AND TOXICITY: In female subjects exposed to N-butyl isocyanate there was an irritating effect to the mucous membranes and temporary lesions to the cardiac conduction system. Occupational exposure to N-butyl isocyanate may occur through inhalation, and dermal contact in the workplace where this chemical is used or manufactured. Butyl isocyanate is an irritant to the eyes of workers in an occupational setting. It is a strong irritant to to the skin. Individuals with a history of asthma, allergies or impaired lung function are at increased risk to the adverse effects of N-butyl isocyanate exposure. ANIMAL STUDIES: In a repeated exposure study, male rats were exposed by inhalation to N-Butyl isocyanate. No treatment related clinical signs were observed in the low dose groups. At the higher dose groups animals appeared unkempt, and exhibited labored breathing, reduced motility and an increased serous discharge from the nose. Substantial decrease in pulmonary function was noted in high dose treated animals. High dose animals exhibited widespread septal destruction, indicative of emphysema. In male rats, exposed to N-butyl isocyanate, neutrophils, LDH, and protein in the bronchoalveolar lavage fluid were elevated. Lung function parameters were decreased. This chemical was a sensitizer in guinea pigs exposed by inhalation. No irritation was observed in a rabbit ear exposed to a solution of N-butyl isocyanate. Butyl isocyanate was highly corrosive to rabbit eyes when instillation of test material to the conjunctival sac. Cats exposed to this chemical orally, had no related clinical effects in hematology or methemoglobin formation. Butyl isocyanate was negative in an Ames test using Salmonella typhimurium strains TA 98, TA 100, TA 1535 and TA 1537 with and without metabolic activation.

Decreased mutation frequency of Escherichia coli H/r30R cells at 800 erg/sq mm UV dose after pretreatment of the cells with n-isobutyl isocyanate /was observed/. /n-Isobutyl isocyanate/

LD50 Guinea pig oral 250 mg/kg|LD50 Mouse iv 1 mg/kg|LD50 Mouse oral 150 mg/kg|LD50 Rat oral 600 mg/kg|For more Non-Human Toxicity Values (Complete) data for N-BUTYL ISOCYANATE (10 total), please visit the HSDB record page.

2% of some worker populations /with the genetic factor of/ immunologic hypersensitivity /have increased risk when exposed to/ isocyanates. /From table, Isocyanates/|Persons with a history of asthma, allergies ... or impaired lung or pulmonary function may be at an increased risk. /Methyl isocyanate/

n-Butyl isocyanate's production and use as an intermediate in the production of carbamate and urea insecticides and fungicides and in the manufacture of sulfonyl urea antidiabetic drugs(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Isocyanates undergo rapid hydrolysis under environmental conditions with half-lives of less than 10 minutes(1). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in moist soil(SRC). Soil adsorption, biodegradation, and volatilization from moist soil are not expected to compete with hydrolysis as important fate and transport processes(SRC). n-Butyl isocyanate may volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 17.6 mm Hg(2).|AQUATIC FATE: Isocyanates undergo rapid hydrolysis under environmental conditions with half-lives of less than 10 minutes(1). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in water(SRC). Sorption to sediments, volatilization, bioconcentration, and biodegradation are not expected to compete with hydrolysis as important fate and transport processes(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-butyl isocyanate, which has a vapor pressure of 17.6 mm Hg at 25 °C(2) is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-butyl isocyanate 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 4 days(SRC), calculated from its rate constant of 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). n-Butyl isocyanate does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(4).

The rate constant for the vapor-phase reaction of n-butyl isocyanate with photochemically-produced hydroxyl radicals has been estimated as 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). n-Butyl isocyanate does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(2). The rate of hydrolysis for n-butyl isocyanate was not available; however, the measured rate constants for the acid catalyzed hydrolysis of methyl isocyanate in aqueous solution at 15 and 25 °C are 5.9X10-4 sec-1 and 1.34X10-3 sec-1, respectively(3). These correspond to half-lives of 20 and 9 min, respectively(SRC). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in moist soil and water(SRC). During a spill, the reaction of isocyanates with water would yield an unstable carbamate which undergoes decarboxylation to form carbon dioxide plus the corresponding amine(4). The amine would then react with isocyanate to form a symmetrically disubstituted urea(4).

Isocyanates undergo rapid hydrolysis under environmental conditions with half-lives of less than 10 minutes(1). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in water(SRC). Bioconcentration is not expected to compete with hydrolysis as an important environmental process(SRC).

Isocyanates undergo rapid hydrolysis under environmental conditions with half-lives of less than 10 minutes(1). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in moist soil and water(SRC). Adsorption to soil and sediment is not expected to compete with hydrolysis as an important environmental process(SRC).

Isocyanates undergo rapid hydrolysis under environmental conditions with half-lives of less than 10 minutes(1). Therefore, hydrolysis is expected to be the dominant fate process for n-butyl isocyanate in moist soil and water(SRC). Volatilization from moist soil and water surfaces is not expected to compete with hydrolysis as an important removal process(SRC). n-Butyl isocyanate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 17.6 mm Hg at 25 °C(2).

n-Butyl isocyanate was detected in the volatile flavor compounds from Oscar Mayer fried bacon at unknown concentrations using gas chromatography and detection by mass spectroscopy or IR spectroscopy(1).

Occupational exposure to n-butyl isocyanate may occur through inhalation and dermal contact with this compound at workplaces where n-butyl isocyanate is produced or used(SRC). The concentration of butyl isocyanate measured in a single air sample during a welding operation in a car repair shop was 9 ug/m(1).

... Reactive isocyanates in general, can react with biological molecules containing amino, alcohol, or sulfhydryl groups, as well as with water. While hydrolysis in an aqueous environment, such as the lung, is theoretically possible, measurements show that alkyl isocyanates are relatively resistant (compared to arylisocyanates) to such hydrolysis.|Isocyanates ... form labile glutathione conjugates from which they can be released. /Isocyanate/|Benomyl (a non-thio fungicide) inhibits hepatic mitochondrial low-Km aldehyde dehydrogenase (mALDH or ALDH2) in ip-treated mice by 50% (IC50) at 7.0 mg/kg, which is surprisingly the same potency range as that for several dithiocarbamate fungicides (and the related alcohol abuse drug disulfiram) and thiocarbamate herbicides previously known for their alcohol-sensitizing action. The mechanism by which benomyl inhibits mALDH was therefore examined, first by comparing the metabolism of benomyl with the aforementioned mono- and dithiocarbamates and second by evaluating the inhibitory potency of the benomyl metabolites. Benomyl in ip-treated mice is converted, via butyl isocyanate, S-(N-butylcarbamoyl)glutathione, and S-(N-butylcarbamoyl)cysteine, to S-methyl N-butylthiocarbamate (MBT), identified as a transient metabolite in liver. MBT is >10-fold more potent than benomyl or butyl isocyanate as an in vivo mALDH inhibitor and is also more potent than the intermediary S-(N-butylcarbamoyl) conjugates. Benomyl and MBT inhibit mouse hepatic mALDH in vitro with IC50s of 0.77 and 8.7 uM, respectively. The potency of MBT is greatly enhanced by fortification of the mitochondria with NADPH alone or plus microsomes giving IC50s of 0.50 and 0.23 uM, respectively. This activation of MBT is almost completely blocked by the cytochrome P450 inhibitor N-benzylimidazole but not by several other cytochrome P450 inactivators. MBT (probably following bioactivation) inhibits mALDH in vivo with an IC50 of 0.3 mg/kg. Two candidate activation products were synthesized for potency determinations. N-Hydroxy MBT (prepared via the trimethylsilyl derivative) was not detected as an MBT metabolite; its low potency also rules against N-hydroxylation as the activation process. MBT sulfoxide, from oxidation of MBT with magnesium monoperoxyphthalate in water, is one of the most potent inhibitors known for mALDH and yeast ALDH in vitro (IC50 0.08-0.09 uM). These findings are consistent with a six-step bioactivation of benomyl, via the metabolites above and N-butylthiocarbamic acid, with MBT as the penultimate and MBT sulfoxide as the ultimate inhibitor of mALDH.|The inhibition of yeast (Saccharomyces cerevesiae) metabolism by fungicidal chemicals was investigated. Glucose- or ethanol-dependent yeast respiration was measured with an oxygen electrode, and manometric determination of carbon dioxide release was used to measure fermentation. Both respiration and fermentation were inhibited more by benomyl than by identical molar concentrations of its breakdown product, carbendazim. Butyl isocyanate, another benomyl breakdown product, inhibited respiration more but inhibited fermentation less than the parent compound. Of the isocyanates tested, hexyl isocyanate was the most inhibitory towards both activities. Captan was more active and iprodione less active than benomyl. Because benomyl rapidly broke down to carbendazim when it was prepared in 80% ethanol, only 59% of the dissolved benomyl was intact when it was added to yeast to determine its effect on respiration or fermentation.

The inactivation of guinea pig liver transglutaminase was investigated using aliphatic isocyanates. It was found that one equivalent of ethyl isocyanate reduced transglutaminase activity to less than 25% within 3 minutes. ... The isocyanates reacted slowly with the sulfhydryl groups of reduced glutathione, indicating enzyme inactivation with transglutaminase. The investigators concluded that alkyl isocyanates inactivate guinea pig liver transglutaminase by forming N-alkylthiocarbamyl ester with the single active site sulfhydryl group of the enzyme. /Aliphatic isocyanates/|Cutinase purified from Fusarium solani f. pisi was effectively inhibited by the fungicide benomyl. This irreversible inhibition was caused by the reaction of butylisocyanate, a breakdown product, with the active serine in the enzyme.|Butyl isocyanate has been found to inactivate yeast alcohol dehydrogenase in a reaction involving 3 mol of SH-groups/mol of enzyme. /No information on the isomer/|Changes in the cytochrome P450 monooxygenase system were investigated in HepG2 cells treated for 24 hr with 1.25, 2.5, 5, 10 and 20 ug/mL of carbendazim (MBC) and n-butylisocyanate (BIC), the principal benomyl metabolites. The results show that n-butylisocyanate leads to a decrease in both ethoxyresorufin deethylase (P4501A1) (EROD) and ethoxycoumarin deethylase (P4502B) (ECOD), whereas MBC has no effect on EROD and increases ECOD. The decrease in ECOD and EROD activities after BIC treatment can be attributed to the detrimental action of this substance. The MBC-induced increase in ethoxycoumarin can be considered an enzyme-specific inductive phenomenon. This hypothesis was confirmed by Western immunoblot analysis and treatment with actinomycin D 8 x 10-4 uM: the first showed an increase in P4502B isoenzyme content and the second evidence of a partial block of the increase in ECOD activity induced by MBC. Given these results, MBC and BIC seem to be the metabolites responsible for the double opposite action of their parent compound benomyl. Data deriving from an equimolar mixture of the two metabolites suggest that benomyl activity on some cytochrome P450 isoenzymes is the result of a balance between the action of the single metabolites

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. (ERG, 2016)

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim calm and warm. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. (ERG, 2016)

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer immediately for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

Rinse with plenty of water for several minutes (remove contact lenses if easily possible).

Noncardiogenic pulmonary edema and bronchospasm are the most immediate serious clinical consequences of isocyanate exposure. Markedly symptomatic patients should receive oxygen, ventilatory support, and an intervenors line. Treatment for asthma includes inhaled sympathomimetics (salbutamol, metaproterenol), intravenous theophylline, parenteral sympathomimetics (epinephrine, terbutaline), and steroids. /Isocyanates/|Most treatment is symptomatic. Mydriatics, systemic analgesics, and topical antibiotics (Sulamyd) may be used for corneal abrasions. There is no effective therapy for sensitized workers, and these people should be moved to a work site devoid of exposure to isocyanates. /Isocyanates/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Monitor for seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patent can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Isocyanates, aliphatic thiocyanates, and related compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Treat exposure to Lethane 60 Lethane 384, Thanite, methyl, ethyl, or isopropyl thiocyanates with the cyanide antidote kit. DIRECT PHYSICIAN ORDER ONLY ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Isocyanates, aliphatic thiocyanates, and related compounds/

/SIGNS AND SYMPTOMS/ ... The skin conditions ranging from localized itching to more or less widespread eczema; conjunctivitis is rare. The commonest and most serious troubles, however, are those affecting the respiratory systems. /Isocyanates/[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1161]|/SIGNS AND SYMPTOMS/ Isocyanates ... produce lung disease /in/ manufacture of plastics and chemical industry. Acute effects /include/ airway irritation, cough, /and/ dyspnea; chronic effects /include/ asthma, /and/ reduced pulmonary function. /From table, isocyanates/[Klaassen, C.D. (ed). Casarett and Doull's Toxicology. The Basic Science of Poisons. 6th ed. New York, NY: McGraw-Hill, 2001., p. 527]|/CASE REPORTS/ The collective poisoning of 16 female subjects was described. No information about the exposure concn. Exposure duration /was/ a few minutes. In addition to the irritating effect on mucous membranes temporary lesions of the cardiac conduction system was interpreted as the result of the action of butyl isocyanate.[European Chemicals Bureau; IUCLID Dataset, Butyl isocyanate (CAS No. 111-36-4) (2000 CD-ROM edition). Available from, as of October 19. 2006: http://esis.jrc.ec.europa.eu/]|/EPIDEMIOLOGY STUDIES/ /During/ 0.5 to 4 yr of follow-up after leaving work, /among total of 104/ subjects with occupational asthma /from isocyanate exposure/, 50 to 82% /had/ persistence of symptoms and 58 to 77% of bronchial hyperresponsiveness. /From table, isocyanates/[Zenz, C., O.B. Dickerson, E.P. Horvath. Occupational Medicine. 3rd ed. St. Louis, MO., 1994, p. 223]|/OTHER TOXICITY INFORMATION/ An industrial hygiene survey in a manufacturing area using butyl isocyanate as an intermediate concluded that noticeable eye irritation, but no odor or respiratory irritation, was associated with exposures of from 0.005 to 0.010 ppm.[European Chemicals Bureau; IUCLID Dataset, Butyl isocyanate (CAS No. 111-36-4) (2000 CD-ROM edition). Available from, as of October 19. 2006: http://esis.jrc.ec.europa.eu/]

butyl isocyanate

Serious local effects by all routes of exposure.

Cough. Sore throat. Laboured breathing. Burning sensation.

Redness. Pain. Skin burns.

Redness. Pain. Burns.

Pesticide, fertilizer, and other agricultural chemical manufacturing|Butane, 1-isocyanato-: ACTIVE|Benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate] is the active ingredient in DuPont Benlate fungicides. The formation of N, N'-dibutylurea (DBU), a phytotoxic degradation product of benomyl, in Benlate formulations was evaluated by analyzing Benlate samples maintained under simulated storage conditions and assessing the effects of temperature and humidity on sample moisture content, benomyl degradation, and the rate of DBU formation. Benomyl degraded during storage by the elimination of n-butylisocyanate (BIC) to form methyl 2-benzimidazole carbamate (MBC; carbendazim). Liberated BIC could then proceed to react with water to form DBU (first-order rate constant of 8.4 x 10(-)(4) s (-)(1)). The degradation of benomyl and subsequent formation of DBU were dependent on the temperature and highly dependent on the humidity of the storage environment. At the lower humidity storage conditions the rates of DBU formation were significantly higher in the dry flowable (DF) formulation than in the wettable powder (WP) formulation. The initial moisture content of Benlate DF samples was higher than those of Benlate WP samples, although the Benlate WP samples absorbed more moisture upon incubation. These results may yield insight on the appearance of high levels of DBU found in some boxes and bags of Benlate DF and Benlate WP formulations.|N,N'-Dibutylurea (DBU) is a breakdown product of benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazole carbamate], the active ingredient in Benlate fungicides, and has been proposed as one cause for crop damage that growers claim to have occurred from the use of Benlate 50 DF fungicide. This study assessed DBU formation upon (1). application of n-butyl-1-[(14)C]butylisocyanate (BIC), the immediate precursor to DBU formation, in four soils at two water potentials (0.03 and 0.1 MPa) and (2). application of benomyl butyl-1-(14)C-benomyl enriched Benlate DF and SP fungicides to two soils at various combinations of negative water potential (0.03 or 0.1 MPa) and temperature (23 or 33 degrees C). Parent compounds, metabolites, and (14)CO(2) were tracked using chromatographic analysis with radioassay and UV detection, liquid scintillation counting, and postextraction oxidation of the soil. At 0.03 MPa in all four BIC-treated soils, DBU formation was never detected. At 0.1 MPa, DBU was detected in two soils, but at concentrations <3.6 ug/kg (0.3 wt % of applied BIC). In both soils treated with benomyl formulations, DBU formation was observed with only Benlate 50 DF application at 0.03 MPa and 23 degrees C, which was followed by rapid dissipation of DBU. The maximum concentration observed was 0.41 ug/g (0.65 wt % of applied benomyl at 62.8 ug/g, which is well below levels currently reported to cause adverse effects to plants. Combined benomyl and carbendazim half-lives in soils across treatments were 2-3 months. This study demonstrated that further production and accumulation of DBU in soils after Benlate application or from residual benomyl remaining in the soil are highly unlikely and that persistence of any DBU in soils is likely to be short-lived.

Isocyanates can be characterized using a strong absorption at 2300-2200 cm-1 in their spectrum. The position of the absorbance is influenced by conjugation and neighboring polar groups. /Isocyanate/|Titrations with dibutylamine can also be used to determine the isocyanate content of isocyanates. An excess of amine in a suitable solvent such as chlorobenzene is added to the sample and the resulting solution is allowed to react and the unreacted amine is back-titrated with dilute hydrochloric acid. For low NCO content levels, a colorimetric method is often used. The isocyanate-containing species is titrated with amine and the unreacted amine is determined using malachite green. /Isocyanate/|Vapor-phase chromatography and high performance liquid chromatography, along with nuclear magnetic resonance spectroscopy, have been used for isomer and composition analysis. /Isocyanate/

Fire Hazards -> Flammable - 3rd degree, Reactive - 2nd degree