過酸化ベンゾイル

外観

白色～ほとんど白色粉末～結晶

定義

本品は、次の化学式で表される過酸化物である。

解説

過酸化ジベンゾイル略称BPO．過酸化ベンゾイルともいう．塩化ベンゾイルを過酸化水素とアルカリまたは過酸化ナトリウムと反応させると得られる．無色の結晶．融点103～104 ℃．爆発性がある．水やエタノールにはほとんど不溶，通常の有機溶媒に可溶．溶液中，熱分解によりC6H5COO·，C6H5·などのラジカルを発生するので，ビニル重合の開始剤として，ポリスチレンやポリアクリロニトリル製造の際に使用される．また，橋かけ硬化剤，あるいは麦の漂白剤としても使用される．

用途

小麦粉·油脂·蝋などの漂白剤、重合触媒、硬化剤、ポリマー架橋剤、医薬·化粧品、ゴム配合剤、乾燥剤、食品添加物(小麦粉等改良剤)

化粧品の成分用途

抗アクネ剤、人工爪剤

効能

抗ニキビ薬, 角質溶解薬

商品名

ベピオ (マルホ)

説明

Benzoyl Peroxide may affect workers in the electronics and plastics (epoxy resins and catalysts) industries, electricians, ceramic workers, dentists and dental technicians, laboratory technicians and bakers. As it was contained in candles, it also induced contact dermatitis in a sacristan. However, some positive tests are of unknown occupational relevance.

化学的特性

Benzoyl peroxide is an odorless, white, or colorless crystalline powder with a faint odor of benzaldehyde resulting from the interaction of benzoyl chloride and a cooled sodium peroxide solution. It is used in specified cheeses at 0.0002% of milk level. It is also used for the bleaching of flour, slowly decomposing to exert its full bleaching action, which results in whiter flour and bread. The major decomposition product of benzoyl peroxide in water was benzoic acid, but trace amounts of phenyl benzoate, phenol, and hydroxybenzoic acids were formed. When carbon-14 la- beled benzoyl peroxide was reacted with whey, the same compounds were produced.

使用

Benzoyl Peroxide is a widely used organic compound of the peroxide family. It is used as a source offree radicals in many organic syntheses andto initiate polymerizations of styrene, vinylchloride, vinyl acetate, and acrylics; to curethermoset polyester resins and silicone rubbers;in medicine for treating acne; and forbleaching vegetable oil, cheese, flour, and fats.

適応症

Benzoyl peroxide is a potent oxidizing agent that has both antimicrobial and comedolytic properties; its primary use is in treating acne vulgaris. It is converted in the skin to benzoic acid; clearance of absorbed drug is rapid, and no systemic toxicity has been observed. The major toxicities are irritation and contact allergy. Outgrowth of bacteria resistant to topical antibiotics used to treat acne can be reduced by the addition of benzoyl peroxide in combination products such as erythromycin (Benzamycin) and clindamycin (Benzaclin).

世界保健機関（WHO）

Benzoyl peroxide slowly releases oxygen and hence is bactericidal. It is also keratolytic, antiseborrheic and irritant. It is used in the treatment of acne. Benzoyl peroxide is listed in the WHO Model List of Essential Drugs.

一般的な説明

Benzoyl peroxide appears as odorless white powder or granules. moderately toxic. Sinks in water. (USCG, 1999)

反応プロフィール

Benzoyl peroxide reacts exothermically withstrong acids, strong bases, amines, reducingagents, and sulfur compounds. Explosionshave been reported when it reacted withcarbon tetrachloride and ethylene (Bolt andJoyce 1947), lithium aluminum hydride(Sutton 1951), N,N-dimethyl aniline (Hornerand Betzel 1953), hot chloroform (NFPA1986), and methyl methacrylate (NFPA1986). Lappin (1948) reported an explosionwhen a bottle was opened. Organic matterentrapped in the threads of the bottleprobably reacted explosively with benzoylperoxide.

危険性

Highly toxic via inhalation. May explode spontaneously when dry (<1% of water). Never mix unless at least 33% water is present. Skin and upper respiratory tract irritant. Questionable carcinogen.

健康ハザード

The health hazard from benzoyl peroxideis low. It can cause irritation of the skin,mucous membranes, and eyes. An intraperitonealinjection of 250 mg/kg was lethal toadult mice. Systemic toxicity in humans isnot known. It may be mild to moderatelytoxic on an acute basis. The oral LD₅₀ valuein rats is 7710 mg/kg (NIOSH 1986). Itstoxicity from inhalation is low; an LC50 valueof 700 ppm in mice is suggested (ACGIH1986).
Benzoyl peroxide may cause gene damageand DNA inhibition. It has been foundto cause skin tumor. The evidence of its carcinogenicityin animals and humans is inadequate.

火災危険

Benzoyl peroxide can cause a major fire and explosion hazard. It is highly flammable and a strong oxidizer; autoignition temperature 80°C (176°F). It ignites instantly. The rate and violence of decomposition and the potential ease of such ignition or decomposition have been experimentally measured by Noller et al. (1964). Lead pipe deformation (LPD), pressure vessel test (PVT), and self-accelerating decomposition test (SADT) have been performed to measure these explosive characteristics. Heating 5 g of benzoyl peroxide in an aluminum tester containing an aperture vent and 6-atm rupture disk, caused the disk to blow up in 95 seconds when the aperture vent area was less than 174.7 mm². Redried material was more violent. The decomposition hazard was greatly reduced with wet and diluted benzoyl peroxide.
Noller et al. (1964) measured the SADT temperature at 82.2°C (180°F), above which the decomposition was self-accelerating, sudden, and produced smoke.
Benzoyl peroxide is a deflagrant, posing a severe explosion hazard. The compound is sensitive to heavy shock, such as impact or blows, as well as to friction and heat. Especially in the dry state, it is highly dangerous.
A water sprinkler should be used to extinguish fires. Water should be used to keep the containers cool.

接触アレルゲン

Benzoyl peroxide is an oxidizing agent widely employed in acne topical therapy. It is also used as a polymerization catalyst of dental or industrial plastics and as a decolorizing agent of flours, oils, fats, and waxes. Irritant or allergic dermatitis may affect workers in the electronics and plastics (epoxy resins and catalysts) industries, electricians, ceramic workers, dentists and dental technicians, laboratory technicians, bakers, and acne patients. As it was contained in candles, it also induced contact dermatitis in a sacristan. Patch tests may be irritant.

安全性プロファイル

Poison by intraperitoneal route.Can cause dermatitis, asthmatic effects, testicular atrophy,and vasodilation. An allergen and eye irritant. Humanmutation data reported. Questionable carcinogen withexperimental tumorigenic data. Moderate fire hazard by

職業ばく露

Used as polymerization initiator, curing agent, and cross-linking agent.

発がん性

When repeatedly applied to the skin of mice, BPO was not carcinogenic . However, benzoyl peroxide is a tumor promoter in mice and hamsters, but has shown no complete carcinogenic or tumor-initiating activity . There has been one controversial Japanese report that was interpreted as BPO being a complete carcinogen. However, when the data were critically evaluated, it was found consistent with BPO acting as a skin tumor promoter and not as a carcinogen. The International Agency for Research on Cancer (IARC) has evaluated the carcinogenicity of benzoyl peroxide. They classified it as Group 3. This means there is limited or inadequate evidence of carcinogenicity for animals and inadequate or absent information for humans. In addition, there are other animals and in vitro studies that continue to support the lack of carcinogenic or mutagenic properties for BPO .

貯蔵

Benzoyl peroxide should be stored in acool and well-ventilated area, isolated fromother chemicals and free of heating andelectrical installations. Dry compound maybe shipped in polyethylene-lined paper bagsor fiber containers packed in wooden boxeso.

輸送方法

UN3104 : Organic peroxide type C, solid, Hazard Class: 5.2; Labels: 5.2—Organic peroxide, Technical Name Required. UN3108 : Organic peroxide type E, solid, Hazard Class: 5.2; Labels: 5.2—Organic peroxide, Technical

純化方法

Dissolve benzoyl peroxide in CHCl3 at room temperature and precipitate it by adding an equal volume of MeOH or pet ether. Similarly it is precipitated from acetone by adding two volumes of distilled water. It has also been crystallised from 50% MeOH and from diethyl ether. Dry it under vacuum at room temperature for 24hours. Store it in a desiccator in the dark at 0o. When purifying in the absence of water it can be EXPLOSIVE, and operations should be done on a very small scale with adequate protection. Large amounts should be kept moist with water and stored in a refrigerator. [Kim et al. J Org Chem 52 3691 1987, Beilstein 9 IV 777.]

不和合性

May explode when heated above melting point, 103 C. A strong oxidizer. Extremely explosionsensitive to heat, shock, friction, and concussion. May explode or cause fire on contact with reducing agents; combustible substances, organic substances, wood, paper, metal powders, lithium aluminum hydride. Violent reaction with alcohols, organic and inorganic acids, and amines.

廃棄物の処理

Pretreatment involves decomposition with sodium hydroxide. The final solution of sodium benzoate, which is very biodegradable, may be flushed into the drain. Disposal of large quantities of solution may require pH adjustment before release into the sewer or controlled incineration after mixing with a noncombustible material.