tert-Butylperbenzoat

1.04 at 77 °F (NTP, 1992) - Denser than water; will sink

1.021 g/cu cm at 25 °C

1 @25 °C

Colorless liquid

Colorless to slight yellow liquid

Liquid

less than 1 mg/mL at 68 °F (NTP, 1992)

Insoluble in water

Soluble in alcohols, esters, ethers, ketones

200 °F (NTP, 1992)

93.4 °C (200.1 °F) - closed cup

>190 °F (>88 °C) - open cup

234 °F at 760 mmHg (NTP, 1992)

112 °C (decomposes)

BP: 75 °C at 0.2 mm Hg

112 °C @760 [mm Hg]

Hazardous decomposition products formed under fire conditions - Carbon oxides.

When heated to decomposition it emits acrid smoke and fumes.

46 °F (NTP, 1992)

8 °C

8 °C

0.33 mmHg at 122 °F (NTP, 1992)

VP: 0.33 mm Hg at 50 °C

0.33 [mm Hg] @50 °C

This chemical does not meet GHS hazard criteria for 1.9% (27 of 1433) of reports.

Danger

H242 (92.8%): Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]

P210, P234, P235, P240, P261, P264, P271, P272, P273, P280, P302+P352, P304+P340, P317, P321, P332+P317, P333+P317, P362+P364, P370+P378, P391, P403, P410, P411, P420, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 1433 reports by companies from 21 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

Chemical: Benzenecarboperoxoic acid, 1,1-dimethylethyl ester

Benzenecarboperoxoic acid, 1,1-dimethylethyl ester is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzenecarboperoxoic acid, 1,1-dimethylethyl ester are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 26-04-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/14209

Benzenecarboperoxoic acid, 1,1-dimethylethyl ester: Does not have an individual approval but may be used under an appropriate group standard

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Organic Peroxide

Organic Peroxide

Organic Peroxide

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

An oxidizer; [Hawley] A strong oxidizer; Explosive; Fire and explosion hazard on contact with organic materials; [CAMEO] In animal experiments, effects included somnolence and seizures after inhalation and liver changes after ingestion; [RTECS] Injection into chicken eggs caused a small increase in embryo malformations; [REPROTOX] Oxidizer that can cause fire on contact with combustible substances; An irritant; [MSDSonline]

Peroxides, Organic

Peroxides, Organic

Peroxides, Organic

Preliminary 2D Animation of Events Leading to 2017 Fire at Arkema Chemical Plant in Crosby, Texas.[U.S. Chemical Safety Board; Preliminary 2D Animation of Events Leading to 2017 Fire at Arkema Chemical Plant in Crosby, Texas; Available from, as of November 27, 2017: http://www.csb.gov/videos/preliminary-2d-animation-of-events-leading-to-2017-fire-at-arkema-chemical-plant-in-crosby-texas/]

Watts P; Food Chem Toxicol 23: 957-60 (1985). Peroxides, genes and cancer is reviewed.

Lai DY, et al; J Environ Sci Hlth 14 (1, Pt C): 63-80 (1996). Carcinogenic potential of organic peroxides prediction based on structure activity relationships and mechanism based short term test.

Strong Oxidizing Agent

Explosive

Explosive

TERT-BUTYL PEROXYBENZOATE explodes with great violence when rapidly heated to a critical temperature; pure form is shock sensitive and detonable [Bretherick 1979 p. 602]. Can ignite upon contact with organic matter or give rise to an explosion [Haz. Chem. Data 1973 p. 79].

TERT-BUTYL PEROXYBENZOATE explodes with great violence when rapidly heated to a critical temperature; pure form is shock sensitive and detonable [Bretherick 1979 p. 602]. Upon contact with organic matter, t-butyl peroxybenzoate can ignite or give rise to an explosion [Haz. Chem. Data 1973 p. 77].

TERT-BUTYL PEROXYBENZOATE explodes with great violence when rapidly heated to a critical temperature; pure form is shock sensitive and detonable [Bretherick 1979 p. 602]. Upon contact with organic matter, t-butyl peroxybenzoate can ignite or give rise to an explosion Haz. Chem. Data 1973 p. 79).

Crosby, Texas, is a small town of 2.3 square miles located about 2 hours drive northeast of Houston. It has a population density of 1000 per square mile versus 26 for the entire State of Texas. ... commercial quantities of peroxide are refrigerated continuously to prevent temperature increase and rapid decomposition. Loss of refrigeration systems for an "extended" period of time can result in massive decomposition and fire in peroxide storage tanks. This is where things went wrong at the Arkema Corporation Plant that manufactures a large number of liquid organic peroxides in Crosby, Texas. Hurricane Harvey flooded this Plant where over one half million pounds of peroxides were stored. Water destroyed the plant's electrical systems and backups thus shutting down refrigeration. "Fearing that the chemicals might explode the Arkema workers, as a last resort, transferred the peroxides to nine refrigerated trailers on the property. All but one of the refrigeration units on those trailers eventually failed, the company said." Out of fear of explosions the workers had to abandon the plant on August 29, resolved to allow explosions take place and peroxides burn. A perimeter of 1.5 miles around the plant was evacuated due to the various hazards. As time passed trailers warmed up and they exploded one by one and caught fire. Billowing thick black smoke and noxious gases were released every time a tanker exploded and burnt. Scores of police officers and others were sent to hospital.

/GUIDE 145 ORGANIC PEROXIDES (Heat and Contamination Sensitive)/ Fire or Explosion: May explode from heat or contamination. May ignite combustibles (wood, paper, oil, clothing, etc.). May be ignited by heat, sparks or flames. May burn rapidly with flare-burning effect. Containers may explode when heated. Runoff may create fire or explosion hazard. /Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

/GUIDE 145 ORGANIC PEROXIDES (Heat and Contamination Sensitive)/ Health: Fire may produce irritating, corrosive and/or toxic gases. Ingestion or contact (skin, eyes) with substance may cause severe injury or burns. Runoff from fire control or dilution water may cause pollution. /Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

/GUIDE 145 ORGANIC PEROXIDES (Heat and Contamination 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, uphill and/or upstream. /Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

/GUIDE 145 ORGANIC PEROXIDES (Heat and Contamination Sensitive)/ Protective Clothing: 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 will only provide limited protection. /Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

For more DOT Emergency Guidelines (Complete) data for t-Butyl peroxy benzoate (16 total), please visit the HSDB record page.

Insoluble in water.

Insoluble in water.

Insoluble in water.

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

Use water spray to cool unopened containers.

Store in original container. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Store at temperatures not exceeding 38 °C/ 100 °F. Keep cool.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations.

Potentially Incompatible Absorbents: Use caution: Liquids with this reactive group classification have been known to react with ... cellulose-based absorbents /and/ expanded polymeric absorbents.

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Keep away from sources of ignition - No smoking. Keep away from heat and sources of ignition.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits 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.

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

3.0 [mg/m3]

33 [mg/m3]

200 [mg/m3]

Excerpt from ERG Guide 145 [Organic Peroxides (Heat and Contamination Sensitive)]:

Excerpt from ERG Guide 146 [Organic Peroxides (Heat, Contamination and Friction Sensitive)]:

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

Eye/face protection: Face shield and safety glasses Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

Skin protection: Handle with gloves.

Body Protection: Complete suit protecting against chemicals. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 240(SRC), determined from a structure estimation method(2), indicates that t-butyl peroxy benzoate is expected to have moderate mobility in soil(SRC). Volatilization of t-butyl peroxy benzoate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.1X10-4 atm-cu m/mole(SRC), using a fragment constant estimation method(3). t-Butyl peroxy benzoate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.3X10-2 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). t-Butyl peroxy benzoate reached 32% of its theoretical BOD in 4 weeks in the Japanese MITI test; the author concluded that test substance hydrolyzed in the test solution to form benzoic acid and t-butanol; benzoic acid was degraded, while t-butanol remained; t-butyl peroxy benzoate was considered not readily biodegradable(4). In another ready biodegradation test, 70% of the theoretical BOD was reached in 4 weeks using an activated sludge inoculum; t-butyl peroxy benzoate was considered readily biodegradable(5). These data suggest that, in addition to hydrolysis, biodegradation is an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 240(SRC), determined from a structure estimation method(2), indicates that t-butyl peroxy benzoate may adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2.1X10-4 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 10 hours and 7 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 1.6(SRC), from an estimated log Kow of 2.9(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). t-Butyl peroxy benzoate reached 32% of its theoretical BOD in 4 weeks in the Japanese MITI test; the author concluded that test substance hydrolyzed in the test solution to form benzoic acid and t-butanol; benzoic acid was degraded, while t-butanol remained; t-butyl peroxy benzoate was considered not readily biodegradable(6). In another ready biodegradation test, 70% of the theoretical BOD was reached in 4 weeks using an activated sludge inoculum; t-butyl peroxy benzoate was considered readily biodegradable(7). These data suggest that, in addition to hydrolysis, biodegradation is an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), t-butyl peroxy benzoate, which has an estimated vapor pressure of 2.3X10-2 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 t-butyl peroxy benzoate 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 days(SRC), calculated from its rate constant of 2.3X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). The UV/vis spectrum for t-butyl peroxy benzoate indicates that it contains chromophores that absorb at wavelengths of 232 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm(SRC).

IDENTIFICATION AND USE: Peroxybenzoic acid, t-butyl ester (TBPB) is a colorless liquid. It is used as a polymerization initiator for polyethylene, polystyrene, polyacrylates, and polyesters, and also as a chemical intermediate. This peroxide is used in various organic syntheses involving coupling reactions of olefins and paraffinic compounds as well as phenolic derivatives. HUMAN STUDIES: Incubation of human keratinocytes prepared from cutaneous squamous cell carcinoma in phosphate-buffered saline containing desferrioxamine with TBPB in the presence of spin trap resulted in the generation of corresponding methyl radical adducts. Since free radicals are suggested to be involved in the cascade of events occurring during tumor promotion, this metabolic capacity may be an important determinant of human cancer risk for hydroperoxides. ANIMAL STUDIES: TBPB tested as a 50% solution by application of 2 drops to rabbit eyes caused slight injury, graded 1 on scale of 0 to 7. Fourteen-day and 13-week oral toxicity studies were conducted using rats and mice. In 14-day studies, TBPB administered by gavage in corn oil in doses ranging from 70 to 1112 mg/kg caused no systemic toxicity. Toxicity in the stomach was demonstrated by the presence of forestomach epithelial hyperplasia, ulceration, and acute inflammation. In studies lasting for 13 weeks, the animals demonstrated hyperplasia of the forestomach mucosa, particularly in dosed rats. TBPB toxicity in mice was limited to increased forestomach weight in most dose level groups and increased severity with dose. TBPB was evaluated for its ability to increase biomarkers of tumor promotion in mouse skin including sustained epidermal hyperplasia, dermal inflammation and oxidative DNA damage. Evaluations were performed using SENCAR mice exposed topically for 4 weeks. TBPB exhibited significant increases in all three biomarkers associated with tumor promoting activity. However, TBPB have not produced detectable mutations in the c-Ha-ras protooncogene, indicating that it is not likely to possess tumor initiating or complete carcinogenic activity. TBPB caused embryotoxicity in 3-day chicken embryos using the air-chamber method. TBPB was found to be positive when tested for mutagenicity using the Salmonella/microsome preincubation assay in both strain TA98 and TA1537 with and without activation and in strain TA100 with activation. In vitro sister chromatid exchange and chromosomal aberrations were noted in Chinese hamster ovary cells.

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of September 21, 2017: http://actor.epa.gov/dashboard/]

The following link will take the user to the National Toxicology Program (NTP) Test Status of Agents Search page, which tabulates the results and current status of tests such as "Short-Term Toxicity Studies", "Long-term Carcinogenicity Studies", "Developmental Studies", "Genetic Toxicology Studies", etc., performed with this chemical. Testing status for tert-Butyl perbenzoate is available.[Available from, as of September 19, 2017: https://ntpsearch.niehs.nih.gov/?e=True&ContentType=Testing+Status]

Using a structure estimation method based on molecular connectivity indices(1), the Koc of t-butyl peroxy benzoate can be estimated to be 240(SRC). According to a classification scheme(2), this estimated Koc value suggests that t-butyl peroxy benzoate is expected to have moderate mobility in soil.

The mutagenicity of tert-butyl peroxybenzoate was evaluated in Salmonella tester strains TA98, TA100, TA1535, TA1537 and TA1538 (Ames Test), both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary toxicity determinations, tert-butyl peroxybenzoate, diluted in DMSO, was tested at concentrations up to 500 ug/plate using the plate incorporation technique. Tert-butyl peroxybenzoate did not cause a positive response in any tester strain with or without metabolic activation.

The ability of tert-butyl peroxybenzoate to induce specific locus mutations at the TK locus in cultured L5178Y mouse lymphoma cells (Mouse Lymphoma Mutagenicity Assay) was evaluated in the presence and absence of metabolic (source not specified) activation. Based on preliminary toxicity determinations, nonactivated cultures were treated in duplicate with 3, 5, 7, 10 and 15 ug/ml, producing a range of 100.2 - 14.6% total survival. Activated cultures treated in duplicate with 5, 7, 10, 15 and 22 ug/ml produced a range of 125.4 - 22.7% total survival. Nonactivated cultures at the three highest doses levels produced better than a two-fold increase in the mutant frequency relative to the solvent control (DMSO), and a dose-response relationship was observed. Activated cultures at the high dose level produced greater than two-fold increase in the mutant frequency relative to the solvent control.

The ability of t-butylperoxybenzoate (BPB) to induce Sister Chromatid Exchange (SCE) in Chinese hamster ovary (CHO) cells was evaluated both in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity tests, BPB, diluted with DMSO, was tested at concentrations of 0, 0.52, 1.8, 5.2, 18 or 52 ug/ml without activation and at concentrations of 0, 0.18, 0.52, 1.8, 5.2 or 18 ug/ml with activation. Fifty cells and 981-993 chromosomes were analyzed per concentration. Concentrations of 1.8 to 52 ug/ml without activation and concentrations of 5.2 and 18 ug/ml with activation induced statistically significant increases in the frequency of SCE relative to solvent controls (p < 0.005, one-tailed student's t-test).

/ALTERNATIVE and IN VITRO TESTS/ Humans are exposed to various peroxy and hydroperoxy compounds which are in use in the cosmetic, pharmaceutical and polymer industries and which are also generated as a result of the peroxidative metabolic conversion of certain lipids. This study was designed to determine whether the organic hydroperoxides, tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate are metabolized by human carcinoma skin keratinocytes to free radicals. Incubation of keratinocytes prepared from cutaneous squamous cell carcinoma in phosphate-buffered saline (pH 7.4) containing desferrioxamine with tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate in the presence of spin trap (3,5-dibromonitrosobenzene sulfonic acid) resulted in the generation of corresponding methyl radical adducts. Prior heating of the cells to 100 degrees C abolished the generation of radical adducts. The addition of ethanol to the reaction mixture also inhibited formation of radical adducts. These data provide the first direct evidence that human carcinoma skin cells can generate free radicals from organic hydroperoxides. Since free radicals are suggested to be involved in the cascade of events occurring during tumor promotion this metabolic capacity may be an important determinant of human cancer risk for hydroperoxides.

AEROBIC: t-Butyl peroxy benzoate, present at 100 mg/L, reached 32% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test, and was considered not readily biodegradable(1); due to its reactive nature in water, t-butyl peroxy benzoate hydrolyzed in the test solution to form benzoic acid and t-butanol; benzoic acid was degraded, while t-butanol remained(1). Using river water in the OECD Closed Bottle test t-butyl peroxy benzoate, present at 1 mg/L, reached 70% of its theoretical BOD in 4 weeks, meeting the 14-day criteria and was considered readily biodegradable(2). t-Butyl peroxy benzoate, present at 2 mg/L, reached 72% of its theoretical BOD in 4 weeks using an activated sludge inoculum in the Closed Bottle test(2). These data suggest that, in addition to hydrolysis, biodegradation of t-butyl peroxy benzoate is an important environmental fate process under certain environmental conditions(SRC).

An estimated BCF of 1.6 was calculated in fish for t-butyl peroxy benzoate(SRC), using an estimated log Kow of 2.9(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for t-butyl peroxy benzoate is estimated as 2.1X10-4 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that peroxybenzoic acid, t-butyl ester 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 10 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 7 days(SRC). t-Butyl peroxy benzoate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.3X10-2 mm Hg(SRC), determined from a fragment constant method(3).

/LABORATORY ANIMALS: Acute Exposure/ t-Butyl perbenzoate tested as 50% solution in dimethyl phthalate by application of 2 drops to rabbit eyes caused slight injury, graded 1 on scale of 0 to 7.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity: Initiation-Promotion/ Screening of newly synthesized organic peroxides for tumor initiating/promoting activity would be greatly facilitated if predictive methodologies could be developed using topical exposures shorter than those required for definitive tumor assessment in mouse skin models. Nine organic peroxides [benzoyl peroxide (BZP), di-t-butyl peroxide (DTBP), t-butyl peroxybenzoate (TBPB), p-t-butyl isopropylbenzene hydroperoxide (TBIBHP), cumene hydroperoxide (CHP), dicetyl peroxydicarbonate (DPD), dicumyl peroxide (DCP), methyl ethyl ketone peroxide (MEKP) and O,O-t-butyl-O-(2-ethylhexyl) monoperoxycarbonate (TBEC)] were evaluated for their ability to increase biomarkers of tumor promotion in mouse skin, i.e. sustained epidermal hyperplasia, dermal inflammation and oxidative DNA damage. Evaluations were performed using SENCAR mice exposed topically for 4 weeks. The organic peroxides varied in their effects on these biomarkers. BZP, TBPB and TBIBHP exhibited significant increases in all three biomarkers associated with tumor promoting activity, CHP produced increases only in sustained epidermal hyperplasia and dermal inflammation, MEKP and DCP produced increases only in sustained epidermal hyperplasia and TBEC produced an increase only in dermal inflammation. DTBP and DPD had no effect on the three parameters studied. TBPB and TBIBHP were selected for further examination of their ability to produce mutations in codons 12, 13 and 61 of the c-Ha-ras protooncogene, i.e. those mutations known to be involved in the initiation of mouse skin tumors, because they were the only peroxides to exhibit significant positive results in all assays except the Ha-ras mutation following 4 weeks of exposure. Evaluations were performed using SENCAR mice dosed topically for 8 or 12 weeks in a complete carcinogenesis protocol or 16 weeks in an initiation/promotion protocol using 7,12-dimethylbenz[a]anthracene, urethane, benzo[a]pyrene and N-methyl-N'-nitro-N-nitrosoguanidine as positive controls. Neither TBPB nor TBIBHP produced detectable mutations in the c-Ha-ras protooncogene, indicating that they are not likely to possess tumor initiating or complete carcinogenic activity.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity: Initiation-Promotion/ Electron paramagnetic resonance spin-trapping has been used to study the production of free radicals from tert-butyl hydroperoxide, tert-butyl peroxybenzoate, cumene hydroperoxide and ethyl hydroperoxide in isolated murine keratinocytes. Free radical species could be trapped from keratinocytes treated with all peroxides, with radicals produced from both one-electron oxidative and reductive pathways. The hindered phenolic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which are known to inhibit peroxide-induced tumor promotion in vivo, decreased the amount of radical adduct production at a concentration of 10 mM, with BHA being significantly more effective than BHT. That all the peroxides in this study produced free radicals in keratinocytes, and that BHA and BHT decreased the amounts of radicals trapped, suggests that free radical production by organic peroxide compounds is involved in their in vivo tumor-promoting activity.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Nine peroxides were tested for embryotoxicity in 3-day chicken embryos using the air-chamber method. The potencies were expressed by the ED50 for the total embryotoxic effect of the chemicals, including deaths and malformations, up to Day 14 of the incubation. The range of the ED50's was from 0.13 to 2.7 umoles per egg and the order of the potencies was as follows: cyclohexanoneperoxide greater than cumolhydroperoxide greater than ethylmethylketoneperoxide greater than dibenzoylperoxide greater than acetylacetoneperoxide greater than perbenzoic acid-tert-butylester greater than dicumylperoxide greater than dilauroylperoxide greater than hydrogen peroxide. All nine peroxides caused malformations at a moderate frequency. The maximum percentage of malformed embryos of the treated varied from the 16% of perbenzoic acid-tert-butylester to the 56% of dicumylperoxide. The high percentage caused by the latter could, however, result from slow diffusion of high lethal doses from the air chamber to the embryo.

For more Non-Human Toxicity Excerpts (Complete) data for t-Butyl peroxy benzoate (6 total), please visit the HSDB record page.

...This study was designed to determine whether the organic hydroperoxides, tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate are metabolized by human carcinoma skin keratinocytes to free radicals. Incubation of keratinocytes prepared from cutaneous squamous cell carcinoma in phosphate-buffered saline (pH 7.4) containing desferrioxamine with tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate in the presence of spin trap (3,5-dibromonitrosobenzene sulfonic acid) resulted in the generation of corresponding methyl radical adducts. Prior heating of the cells to 100 degrees C abolished the generation of radical adducts. The addition of ethanol to the reaction mixture also inhibited formation of radical adducts. These data provide the first direct evidence that human carcinoma skin cells can generate free radicals from organic hydroperoxides. Since free radicals are suggested to be involved in the cascade of events occurring during tumor promotion this metabolic capacity may be an important determinant of human cancer risk for hydroperoxides.

Used as polymerization initiator (polyethylene, polystyrene, polyacrylates, and polyesters) and curing agent (unsaturated polyesters and silicon rubber); Also used as a chemical intermediate; [HSDB]

Plastic Composites Manufacturing [Category: Industry]

Polymerization initiator for polyethylene, polystyrene, polyacrylates, and polyesters; chemical intermediate.

It is ... effective as a medium temperature initiator for the polymerization and/or cross-linking of methyl methacrylate, acrylonitrile, isoprene, styrene, and butadiene. Low-density polyethylene of excellent mechanical properties is obtained when using this peroxide as an initiator. This peroxide is also used in various organic syntheses involving coupling reactions of olefins and paraffinic compounds as well as phenolic derivatives.

... curing agent in the polymer industry.

Silicon rubber curing agent; polyester crosslinking agent.

2023: 2,500,000 - <4,000,000 lb

(1972) 7.00X10+8 GRAMS

(1975) 1.00X10+9 GRAMS

(1993) 1,963,000 kg

Non-confidential 2016 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Benzenecarboperoxoic acid, 1,1-dimethylethyl ester:

t-Butyl peroxybenzoate is produced by reacting t-butyl hydroperoxide with benzoyl chloride in the presence of a base.

t-Butyl hydroperoxide + benzoyl chloride (dehydrochlorination).

REACTION OF T-BUTYL HYDROPEROXIDE WITH BENZOYL CHLORIDE (OR ANHYDRIDE) IN THE PRESENCE OF A BASE

CBI

Benzenecarboperoxoic acid, 1,1-dimethylethyl ester: ACTIVE