tert-Butyl peroxybenzoate

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

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

H315 (97.8%): Causes skin irritation [Warning Skin corrosion/irritation]

H317 (76.9%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H332 (74.2%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H400 (76.8%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H412 (51.3%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

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.

Reported as not meeting GHS hazard criteria per 27 of 1433 reports by companies.

There are 20 notifications provided by 1406 of 1433 reports by companies with hazard statement code(s).

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.

H242 (100%): Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]

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

H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H332 (100%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H412 (100%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.

H227: Combustible liquid [Warning Flammable liquids]

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

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P210, P234, P235, P240, P260, P261, P264, P270, P271, P272, P273, P280, P302+P352, P304+P340, P308+P316, P317, P321, P333+P317, P362+P364, P370+P378, P391, P403, P405, P410, P411, P420, and P501 (click each P-code to see the statement)

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

P210, P234, P235, P240, P264+P265, P280, P305+P351+P338, P337+P317, P370+P378, P403, P410, P411, P420, and P501 (click each P-code to see the statement)

H315: Causes skin irritation [Warning Skin corrosion/irritation]

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

Refer to the "General First Aid" section. Specific First Aid: Contaminated clothing may be a fire risk when dry. (ERG, 2024)

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.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

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

SMALL FIRE: Water spray or fog is preferred; if water not available use dry chemical, CO2 or regular foam.

LARGE FIRE: Flood fire area with water from a distance. Use water spray or fog; avoid aiming straight or solid streams directly onto the product. Do not move cargo or vehicle if cargo has been exposed to heat. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

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

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.

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

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.

LARGE SPILL: Consider initial evacuation for at least 250 meters (800 feet) in all directions.

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)

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

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.

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)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Keep combustibles (wood, paper, oil, etc.) away from spilled material. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Keep substance wet using water spray. Stop leak if you can do it without risk.

SMALL SPILL: Pick up with inert, damp, non-combustible material using clean, non-sparking tools and place into loosely covered plastic containers for later disposal.

LARGE SPILL: Wet down with water and dike for later disposal. Prevent entry into waterways, sewers, basements or confined areas. DO NOT CLEAN-UP OR DISPOSE OF, EXCEPT UNDER SUPERVISION OF A SPECIALIST. (ERG, 2024)

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

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.

3.0 [mg/m3]

33 [mg/m3]

200 [mg/m3]

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

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)

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.

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Tert-butyl peroxybenzoate, [<= 50% with inert inorganic solid] is a clear, colorless to slightly yellow liquid with a mild, aromatic odor. Also stored and transported as a mixture with inert solids and as a solvent slurry, to mitigate the explosion hazard.

Tert-butyl peroxybenzoate, [<= 75% in solution] is a clear, colorless to slightly yellow liquid with a mild, aromatic odor. It also is stored and transported as a mixture with inert solids and as a solvent slurry, to mitigate the explosion hazard.

Tert-butyl peroxybenzoate, [technically pure] is a clear, colorless to slightly yellow liquid with a mild, aromatic odor. Also stored and transported as a mixture with inert solids and as a solvent slurry, to mitigate the explosion hazard.

Liquid; CBI

Colorless liquid; mp = 8.5 deg C; [Hawley] Colorless to slightly yellow liquid; mp = 8 deg C; [HSDB]

Colorless liquid

Colorless to slight yellow liquid

Mild aromatic odor

234 °F at 760 mmHg (NTP, 1992)

112 °C (decomposes)

BP: 75 °C at 0.2 mm Hg

112 °C @760 [mm Hg]

46 °F (NTP, 1992)

200 °F (NTP, 1992)

93.4 °C (200.1 °F) - closed cup

>190 °F (>88 °C) - open cup

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

Insoluble in water

Soluble in alcohols, esters, ethers, ketones

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

1.021 g/cu cm at 25 °C

1 @25 °C

0.33 mmHg at 122 °F (NTP, 1992)

VP: 0.33 mm Hg at 50 °C

0.33 [mm Hg] @50 °C

Stable under recommended storage conditions.

The physical properties of t-butyl perbenzoate are that of an intermediate fire hazard; however, other sources refer to it as a fire hazard with 8.16% active oxygen. The liquid at 99% purity showed a slow pressure rise with only 1 g of igniter; therefore, it is not a deflagration hazard. It also has a low shock or impact sensitivity.

Hazardous decomposition products formed under fire conditions - Carbon oxides.

When heated to decomposition it emits acrid smoke and fumes.

Index of refraction = 1.4990 at 20 °C/D

Specific gravity: 1.04 at 25 °C/25 °C

Half-life of ten hours at 104 °C

Chemical shift

Lineshape

Flammable agents - 3rd degree

Reactive agents - 3rd degree

FCS -> FDA Inventory of Food Contact Substances Listed in 21 CFR

Plastics & Rubber -> Curing Agents (Aromatic)

Insoluble in water.

Peroxides, Organic

Strong Oxidizing Agent

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).

Reacts violently with: Strong acids, bases, reducing agents, oxidizing agents, amines, brass, copper.

Organic substances can ignite or explode upon contact with t-butyl perbenzoate.

Explosive reaction on contact with organic matter or copper (I) bromide plus limonene.

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.

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

LC (rat) > 57 mg/m3/4h

LD50 Rat oral 3639-4838 mg/kg /From table/

LD50 Mouse oral 914 mg/kg

LD50 Rat oral 1012 mg/kg

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Organic peroxides/

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 ... . Anticipate 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 patient can swallow, has a strong gag reflex, and does not drool ... . Do not attempt to neutralize because of exothermic reaction. Cover skin burns with dry, sterile dressings after decontamination ... . /Organic peroxides/

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. Early intubation, at the first sign of upper airway obstruction, may be necessary. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5K TKO. 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. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Organic peroxides/

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Organic acids and related compounds/

For more Antidote and Emergency Treatment (Complete) data for t-Butyl peroxy benzoate (6 total), please visit the HSDB record page.

/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.

/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.

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]

Studies were conducted on the toxicity, stability, dermal absorption, and tissue distribution of t-butyl-perbenzoate (BP). Fourteen day and 13 week oral toxicity studies were conducted using F344/N rats and B6C3Fl mice. BP was mutagenic in Salmonella typhimurium strains (TA-100), (TA-1537), and (TA-98) with or without metabolic activation. In vitro sister chromatid exchange and chromosomal aberrations were noted in Chinese hamster ovary cells. BP was rapidly degraded in blood, stomach contents and liver homogenates, or in the presence of glutathione. In 14 day studies, BP 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. BP toxicity in mice was limited to incr forestomach weight in most dose level groups and incr severity with dose. The ... no observed effect level for BP was approximately 30 mg/kg and that systemic toxicity was not observed with oral doses as high as 1112 mg/kg.

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).

t-Butyl peroxy benzoate's production and use as a polymerization initiator, chemical intermediate, and as a hardener for polyester resins may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 2.3X10-2 mm Hg at 25 °C indicates t-butyl peroxy benzoate will exist solely as a vapor in the atmosphere. Vapor-phase t-butyl peroxy benzoate 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 days. The UV/vis spectrum for t-butyl peroxy benzoate indicates that it contains chromophores that absorb at wavelengths of 232 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm. If released to soil, t-butyl peroxy benzoate is expected to have moderate mobility based upon an estimated Koc of 240. Volatilization from moist soil surfaces may be an important fate process based upon an estimated Henry's Law constant of 2.1X10-4 atm-cu m/mole. t-Butyl peroxy benzoate is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI test, 32% of the theoretical BOD was reached 4 weeks; however the test substance hydrolyzed in the test solution to form benzoic acid, which biodegraded, and t-butanol. In the Closed Bottle test, 70% of the theoretical BOD was reached in 4 weeks. These data indicate that, in addition to hydrolysis, biodegradation is an important environmental fate process in soil and water. If released into water, t-butyl peroxy benzoate may 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 10 hours and 7 days, respectively. An estimated BCF of 1.6 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is expected to be an important environmental fate process under environmental conditions (pH 5 to 9). t-Butyl peroxy benzoate is expected to undergo hydrolysis in water with half-lives of 976 and 38 hours pH values of 7 and 9, respectively. Occupational exposure to peroxybenzoic acid, t-butyl ester may occur through dermal contact with this compound at workplaces where t-butyl peroxy benzoate is produced or used. Monitoring data was not located; however, the majority of this substance is used in captive processes as an industrial reactant, suggesting that the general population will have limited or no exposure under ambient environmental conditions. (SRC)

t-Butyl peroxy benzoate's production and use as a polymerization initiator(1), chemical intermediate(1), and as a hardener for polyester resins(2) 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 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).

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).

The rate constant for the vapor-phase reaction of t-butyl peroxy benzoate with photochemically-produced hydroxyl radicals has been estimated as 2.3X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). t-Butyl peroxy benzoate is expected to undergo hydrolysis in the ambient environment and in alkaline soils and waters(2,3). Peroxide esters, like t-butyl peroxy benzoate, are expected to undergo hydrolysis in the environment more readily than non-peroxide esters(3,4); hydrolysis yields benzoic acid and t-butyl hydroperoxide and t-butanol(4,5). In an OECD guideline study, hydrolysis half-lives at 25 °C, were reported as 1900, 976, and 38 hours at pH values of 4, 7, and 9, respectively(4); hydrolysis half-lives at 50 °C, were reported as 79, 54, and 2.6 hours at pH values of 4, 7, and 9, respectively(4). The UV/vis spectrum for t-butyl peroxy benzoate indicates that it contains chromophores that absorb at wavelengths of 232 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm(SRC).

The main causes of unintended decompositions of organic peroxides are heat energy from heating sources and mechanical shock, i.e., impact or friction. In addition, certain contaminants, i.e., metal salts, amines, acids, and bases, initiate or accelerate organic peroxide decompositions at temperatures at which the peroxide is normally stable. These reactions also liberate heat, thus further accelerating the decomposition. Commercial products often contain diluents that desensitize neat peroxides to these hazards. Commercial organic peroxide decompositions are low order deflagrations rather than detonations. /Organic peroxides/

Under certain thermal and photochemical conditions, t-alkyl peroxyesters, such as peroxybenzoic acid, t-butyl ester, will undergo homolysis to generate free radicals, although this is not expected to occur in ambient environmental conditions(1).

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).

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 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).

According to the 2016 TSCA Inventory Update Reporting data, 3 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of t-butyl peroxy benzoate in the United States may be as low as 25 workers but fewer than 500 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 27,644 workers (10,655 of these are female) were potentially exposed to t-butyl peroxy benzoate in the US(1). Occupational exposure to t-butyl peroxy benzoate may occur through dermal contact with this compound at workplaces where t-butyl peroxy benzoate is produced or used. Monitoring data were not located; however, the majority of this substance is used in captive processes as an industrial reactant(2), suggesting that the general population will have limited or no exposure under ambient environmental conditions(SRC).

t-Butyl peroxy benzoate's production and use as a polymerization initiator, chemical intermediate, and as a hardener for polyester resins may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 2.3X10-2 mm Hg at 25 °C indicates t-butyl peroxy benzoate will exist solely as a vapor in the atmosphere. Vapor-phase t-butyl peroxy benzoate 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 days. The UV/vis spectrum for t-butyl peroxy benzoate indicates that it contains chromophores that absorb at wavelengths of 232 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm. If released to soil, t-butyl peroxy benzoate is expected to have moderate mobility based upon an estimated Koc of 240. Volatilization from moist soil surfaces may be an important fate process based upon an estimated Henry's Law constant of 2.1X10-4 atm-cu m/mole. t-Butyl peroxy benzoate is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI test, 32% of the theoretical BOD was reached 4 weeks; however the test substance hydrolyzed in the test solution to form benzoic acid, which biodegraded, and t-butanol. In the Closed Bottle test, 70% of the theoretical BOD was reached in 4 weeks. These data indicate that, in addition to hydrolysis, biodegradation is an important environmental fate process in soil and water. If released into water, t-butyl peroxy benzoate may 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 10 hours and 7 days, respectively. An estimated BCF of 1.6 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is expected to be an important environmental fate process under environmental conditions (pH 5 to 9). t-Butyl peroxy benzoate is expected to undergo hydrolysis in water with half-lives of 976 and 38 hours pH values of 7 and 9, respectively. Occupational exposure to peroxybenzoic acid, t-butyl ester may occur through dermal contact with this compound at workplaces where t-butyl peroxy benzoate is produced or used. Monitoring data was not located; however, the majority of this substance is used in captive processes as an industrial reactant, suggesting that the general population will have limited or no exposure under ambient environmental conditions. (SRC)

t-Butyl peroxy benzoate's production and use as a polymerization initiator(1), chemical intermediate(1), and as a hardener for polyester resins(2) 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 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).

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).

The rate constant for the vapor-phase reaction of t-butyl peroxy benzoate with photochemically-produced hydroxyl radicals has been estimated as 2.3X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). t-Butyl peroxy benzoate is expected to undergo hydrolysis in the ambient environment and in alkaline soils and waters(2,3). Peroxide esters, like t-butyl peroxy benzoate, are expected to undergo hydrolysis in the environment more readily than non-peroxide esters(3,4); hydrolysis yields benzoic acid and t-butyl hydroperoxide and t-butanol(4,5). In an OECD guideline study, hydrolysis half-lives at 25 °C, were reported as 1900, 976, and 38 hours at pH values of 4, 7, and 9, respectively(4); hydrolysis half-lives at 50 °C, were reported as 79, 54, and 2.6 hours at pH values of 4, 7, and 9, respectively(4). The UV/vis spectrum for t-butyl peroxy benzoate indicates that it contains chromophores that absorb at wavelengths of 232 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm(SRC).

The main causes of unintended decompositions of organic peroxides are heat energy from heating sources and mechanical shock, i.e., impact or friction. In addition, certain contaminants, i.e., metal salts, amines, acids, and bases, initiate or accelerate organic peroxide decompositions at temperatures at which the peroxide is normally stable. These reactions also liberate heat, thus further accelerating the decomposition. Commercial products often contain diluents that desensitize neat peroxides to these hazards. Commercial organic peroxide decompositions are low order deflagrations rather than detonations. /Organic peroxides/

Under certain thermal and photochemical conditions, t-alkyl peroxyesters, such as peroxybenzoic acid, t-butyl ester, will undergo homolysis to generate free radicals, although this is not expected to occur in ambient environmental conditions(1).

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).

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 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).

According to the 2016 TSCA Inventory Update Reporting data, 3 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of t-butyl peroxy benzoate in the United States may be as low as 25 workers but fewer than 500 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 27,644 workers (10,655 of these are female) were potentially exposed to t-butyl peroxy benzoate in the US(1). Occupational exposure to t-butyl peroxy benzoate may occur through dermal contact with this compound at workplaces where t-butyl peroxy benzoate is produced or used. Monitoring data were not located; however, the majority of this substance is used in captive processes as an industrial reactant(2), suggesting that the general population will have limited or no exposure under ambient environmental conditions(SRC).

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.

/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.

UN 3103; Organic peroxide type C, liquid

UN 3105; Organic peroxide type D, liquid

UN 3106; Organic peroxide type D, solid

UN 3109; Organic peroxide type F, liquid

IMO 5.2; Organic peroxide type C, liquid; Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid

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. Organic peroxide type C, liquid; organic peroxide type D, liquid; organic peroxide type D, solid; and organic peroxide type F, liquid are included on the dangerous goods list. /Organic peroxide type C, liquid; Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

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. Organic peroxide type C, liquid; organic peroxide type D, liquid; organic peroxide type D, solid; and organic peroxide type F, liquid are included on the dangerous goods list. /Organic peroxide type C, liquid; Organic peroxide type D, liquid; Organic peroxide type D, solid; Organic peroxide type F, liquid/

Organic Peroxide