Dibutyl hydrogen phosphite

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (94.4%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H411 (14.9%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

H412 (86%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P264, P264+P265, P273, P280, P302+P352, P305+P351+P338, P321, P332+P317, P337+P317, P362+P364, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 698 reports by companies from 7 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P264+P265, P280, P302+P352, P305+P351+P338, P317, P321, P337+P317, P362+P364, and P501 (click each P-code to see the statement)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Refer to the "General First Aid" section. Specific First Aid: For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required. (ERG, 2024)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

Foam, carbon dioxide, dry chemical.

If material involved in fire: use water in flooding quantities as fog. Apply water from as far as distance as possible. Use dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

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: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank 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, 2024)

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.

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 material not involved in fire: Keep material out of water sources and sewers. Build dikes to contain flow as necessary.

Personnel protection: Keep upwind. Avoid bodily contact with the material. Avoid breathing vapors. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Avoid bodily contact with the material. ... .

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

9.6 [mg/m3]

110 [mg/m3]

630 [mg/m3]

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

Respiratory protection (supplied-air respirator with full facepiece or self-contained breathing apparatus) should be available where these compounds are manufactured or used and should be worn in case of emergency and overexposure. /Phosphorus compounds/

Dibutyl phosphite appears as a clear colorless liquid. Contact may severely irritate skin, eyes and mucous membranes.

Water-white liquid; [Hawley] Clear colorless liquid; [MSDSonline]

Water-white liquid

Penetrating

95 °C at 1 mm Hg

BP: 130 to 133 °C at 19 mm Hg; 76 to 78 °C at 1 to 2 mm Hg

120 °F (NFPA, 2010)

Sol in common organic solvents

In water, 7,300 mg/L at 25 °C

0.98685 at 25 °C

0.986 @25 °C

6.7 (Air= 1)

0.02 [mmHg]

Vapor pressure: < 1 mm Hg at 20 °C; BP = 116-117 °C at 8 mm Hg

1 [mm Hg] @95 °C

When heated to decomposition or on contact with acid or acid fumes it emits highly toxic fumes of /phosphorus oxides/.

/Dibutyl hydrogen/ phosphite was being distilled under reduced pressure. At the end of distillation the air-bleed was opened more fully, when spontaneous combustion occurred inside the flask, probably of phosphine formed by thermal decomp.

Index of refraction: 1.4220 at 20 °C/D

Other Classes -> Phosphite Compounds

Flammable. About the same density as water and slowly dissolves in water. Slowly reacts with water to form phosphoric acid and corresponding organic alcohol.

Sulfonates, Phosphonates, and Thiophosphonates, Organic

Reducing Agents, Weak

Organophosphates are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.

Can react vigorously with oxidizing materials.

LC50 (rat) > 20,000 mg/m3

LD50 Rat oral 3.2 g/kg /From table/

LD50 Rat dermal 2.0 g/kg /From table/

/LABORATORY ANIMALS: Acute Exposure/ Rated 9 on rabbit eyes. Most severe injuries have been rated 10.

/OTHER TOXICITY INFORMATION/ The toxicity of phosphites appeared to be related to their lipophilic & electronic properties. The most toxic phosphites had electronegative substituents & unsaturated alkyl chains. /Phosphites/

Dibutyl hydrogen phosphite's production and use as a solvent, antioxidant, and chemical intermediate may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 2.4X10-2 mm Hg at 25 °C indicates dibutyl hydrogen phosphite will exist solely as a vapor in the atmosphere. Vapor-phase dibutyl hydrogen phosphite will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 7 hours. Dibutyl hydrogen phosphite may be subject to photooxidation based on a study on analogous diethyl hydrogen phosphite which degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air; degradation in sunlight also occurred but at a slow rate. If released to soil, dibutyl hydrogen phosphite is expected to have very high mobility based upon an estimated Koc of 33. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.8X10-5 atm-cu m/mole. Biodegradation data were not available. If released into water, dibutyl hydrogen phosphite is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 3 days and 26 days, respectively. An estimated BCF of 4 suggests the potential for bioconcentration in aquatic organisms is low. Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol with reported hydrolysis half-lives ranging from 2.2 to 60.7 days. Occupational exposure to dibutyl hydrogen phosphite may occur through inhalation and dermal contact with this compound at workplaces where dibutyl hydrogen phosphite is produced or used. (SRC)

Dibutyl hydrogen phosphite's use as a solvent, antioxidant, and chemical intermediate(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 33(SRC), determined from a water solubility of 7.3X10+3 mg/L(2) and a regression-derived equation(3), indicates that dibutyl hydrogen phosphite is expected to have very high mobility in soil(SRC). Volatilization of dibutyl hydrogen phosphite from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10+5 atm-cu m/mole(SRC), using a fragment constant estimation method(4). Dibutyl hydrogen phosphite is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-2 mm Hg(SRC), determined from a fragment constant method(5). Biodegradation data were not available(SRC, 2006).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 33(SRC), determined from a water solubility of 7.3X10+3 mg/L(2) and a regression-derived equation(3), indicates that dibutyl hydrogen phosphite 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 1.8X10-5 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 and 26 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 4(SRC), from its water solubility(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol in a base catalyzed reaction(7). Reported hydrolysis half-lives range from 2.2(8) to 60.7 days(9). Biodegradation data were not available(SRC, 2006).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyl hydrogen phosphite, which has an estimated vapor pressure of 2.4X10-2 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyl hydrogen phosphite 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 7 hours(SRC), calculated from its rate constant of 5.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). A study on analogous diethyl hydrogen phosphite demonstrated that the ester was degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air(4). Degradation in sunlight also occurred but at a slow rate. Therefore, dibutyl hydrogen phosphite could be subject to photooxidation(SRC).

The rate constant for the vapor-phase reaction of dibutyl hydrogen phosphite with photochemically-produced hydroxyl radicals has been estimated as 5.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1).

Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol in a base catalyzed reaction(2). The rate constant for the hydrolysis of dibutyl hydrogen phosphite at 50 °C is 0.26X10-5/sec and its activation energy is 22.8 kcal/mole(1). Therefore, its hydrolytic half-lives at 50 and 25 °C are 3.1 and 60.7 days, respectively(SRC). Another investigator reported a basic hydrolysis rate constant at 20 °C of 36.2 l/sec mole(3), which would indicate a hydrolytic half-life of 2.2 days at pH 7 and 32 min at pH 9(3). A study on analogous diethyl hydrogen phosphite demonstrated that the ester was degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air(4). Degradation in sunlight also occurred but at a slow rate. Therefore, dibutyl hydrogen phosphite could be subject to photooxidation(SRC).

An estimated BCF of 4 was calculated in fish for dibutyl hydrogen phosphite(SRC), using a water solubility off 7.3X10+3 mg/L(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 Koc of dibutyl hydrogen phosphite is estimated as 33(SRC), using a water solubility of 7.3X10+3 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that dibutyl hydrogen phosphite is expected to have very high mobility in soil.

The Henry's Law constant for dibutyl hydrogen phosphite is estimated as 1.8X10-5 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dibutyl hydrogen phosphite 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 days(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 26 days(SRC). Dibutyl hydrogen phosphite's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Dibutyl hydrogen phosphite is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-2 mm Hg(SRC), determined from a fragment constant method(3).

Occupational exposure to dibutyl hydrogen phosphite may occur through inhalation and dermal contact with this compound at workplaces where dibutyl hydrogen phosphite is produced or used. (SRC)

Dibutyl hydrogen phosphite's production and use as a solvent, antioxidant, and chemical intermediate may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 2.4X10-2 mm Hg at 25 °C indicates dibutyl hydrogen phosphite will exist solely as a vapor in the atmosphere. Vapor-phase dibutyl hydrogen phosphite will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 7 hours. Dibutyl hydrogen phosphite may be subject to photooxidation based on a study on analogous diethyl hydrogen phosphite which degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air; degradation in sunlight also occurred but at a slow rate. If released to soil, dibutyl hydrogen phosphite is expected to have very high mobility based upon an estimated Koc of 33. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.8X10-5 atm-cu m/mole. Biodegradation data were not available. If released into water, dibutyl hydrogen phosphite is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 3 days and 26 days, respectively. An estimated BCF of 4 suggests the potential for bioconcentration in aquatic organisms is low. Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol with reported hydrolysis half-lives ranging from 2.2 to 60.7 days. Occupational exposure to dibutyl hydrogen phosphite may occur through inhalation and dermal contact with this compound at workplaces where dibutyl hydrogen phosphite is produced or used. (SRC)

Dibutyl hydrogen phosphite's use as a solvent, antioxidant, and chemical intermediate(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 33(SRC), determined from a water solubility of 7.3X10+3 mg/L(2) and a regression-derived equation(3), indicates that dibutyl hydrogen phosphite is expected to have very high mobility in soil(SRC). Volatilization of dibutyl hydrogen phosphite from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10+5 atm-cu m/mole(SRC), using a fragment constant estimation method(4). Dibutyl hydrogen phosphite is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-2 mm Hg(SRC), determined from a fragment constant method(5). Biodegradation data were not available(SRC, 2006).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 33(SRC), determined from a water solubility of 7.3X10+3 mg/L(2) and a regression-derived equation(3), indicates that dibutyl hydrogen phosphite 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 1.8X10-5 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 and 26 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 4(SRC), from its water solubility(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol in a base catalyzed reaction(7). Reported hydrolysis half-lives range from 2.2(8) to 60.7 days(9). Biodegradation data were not available(SRC, 2006).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyl hydrogen phosphite, which has an estimated vapor pressure of 2.4X10-2 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyl hydrogen phosphite 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 7 hours(SRC), calculated from its rate constant of 5.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). A study on analogous diethyl hydrogen phosphite demonstrated that the ester was degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air(4). Degradation in sunlight also occurred but at a slow rate. Therefore, dibutyl hydrogen phosphite could be subject to photooxidation(SRC).

The rate constant for the vapor-phase reaction of dibutyl hydrogen phosphite with photochemically-produced hydroxyl radicals has been estimated as 5.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1).

Dibutyl hydrogen phosphite hydrolyzes to phosphorous acid and butanol in a base catalyzed reaction(2). The rate constant for the hydrolysis of dibutyl hydrogen phosphite at 50 °C is 0.26X10-5/sec and its activation energy is 22.8 kcal/mole(1). Therefore, its hydrolytic half-lives at 50 and 25 °C are 3.1 and 60.7 days, respectively(SRC). Another investigator reported a basic hydrolysis rate constant at 20 °C of 36.2 l/sec mole(3), which would indicate a hydrolytic half-life of 2.2 days at pH 7 and 32 min at pH 9(3). A study on analogous diethyl hydrogen phosphite demonstrated that the ester was degraded to CO2 (half-life 28.8 hr) by UV radiation in moist air(4). Degradation in sunlight also occurred but at a slow rate. Therefore, dibutyl hydrogen phosphite could be subject to photooxidation(SRC).

An estimated BCF of 4 was calculated in fish for dibutyl hydrogen phosphite(SRC), using a water solubility off 7.3X10+3 mg/L(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 Koc of dibutyl hydrogen phosphite is estimated as 33(SRC), using a water solubility of 7.3X10+3 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that dibutyl hydrogen phosphite is expected to have very high mobility in soil.

The Henry's Law constant for dibutyl hydrogen phosphite is estimated as 1.8X10-5 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dibutyl hydrogen phosphite 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 days(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 26 days(SRC). Dibutyl hydrogen phosphite's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Dibutyl hydrogen phosphite is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-2 mm Hg(SRC), determined from a fragment constant method(3).

Occupational exposure to dibutyl hydrogen phosphite may occur through inhalation and dermal contact with this compound at workplaces where dibutyl hydrogen phosphite is produced or used. (SRC)

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.

Corrosive