гудрон

Химические свойства

Asphalt fumes are flammable when hot and may contain hydrogen sulfide and human carcinogen, such as benzo(a)pyrene and dibenz(a,h)anthracene. Fumes generated during the production or application of asphalt (a dark-brown to black cement-like substance manufactured by the vacuum distillation of crude petroleum oil).

Использование

Acid, alkali, and waterproof coatings; black varnishes, lacquers, baking enamels, and japans; wire-insulation compounds; linoleum and floor tile; paving; insulation; diluent in low-grade rubber compounds; possible source of gasoline, fuel oil, and metallurgical coke.

Определение

An asphaltic material or solidified hydrocarbon found only in Utah and Colorado. One of the purest (9.9%) natural bitumens. Said to be the first solid hydrocarbon to be converted to gasoline.

Общее описание

Dark liquid. A mixture of heavy hydrocarbon residues including saturated and unsaturated hydrocarbons and aromatic hydrocarbons (Reactive Groups 16, 28, and 29). Depending on the blend includes various heterocyclic hydrocarbons containing sulfur and nitrogen.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

ASPHALT burns readily when heated or ignited in the presence of air or oxygen. May be incompatible with strong oxidizing agents like nitric acid. Charring may occur followed by ignition. Mostly unreactive in other settings. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.

Опасность

Irritant, skin sensitizer.

Угроза здоровью

Acute exposure to asphalt fumes causes irritative effects. Certain extracts of asphalt have caused a carcinogenic skin response in experimental animals.
The chemical composition of vapors and fumes from asphalt products is variable and depends on the crude petroleum source, type of asphalt, temperature, and extent of mixing.1 Therefore, the adverse effects from asphalt may also vary considerably depending on the source of exposure.

Пожароопасность

Flash point data for ASPHALTUM are not available; however ASPHALTUM is probably combustible.

Промышленное использование

Asphalt refers to varieties of naturally occurringbitumen. Asphalt is also produced as a petroleumbyproduct. Both substances are black andlargely soluble in carbon disulfide. Asphalts areof variable consistency, ranging from a highlyviscous fluid to a solid.Asphalt is derived from petroleum in commercialquantities by removal of volatile components.It is an inexpensive construction material used primarily as a cementing andwaterproofing agent.Asphalt is composed of hydrocarbons andheterocyclic compounds containing N2, sulfur,O2; its components vary in molecular weightfrom about 400 to 5000. It is thermoplastic andviscoelastic; at high temperatures or over long loading times it behaves as a viscous fluid; atlow temperatures or short loading times as anelastic body.

Профиль безопасности

Suspected carcinogen with experimental carcinogenic and tumorigenic data. A moderate irritant. May contain carcinogenic components. Combustible when exposed to heat or flame. To fight fire, use foam, CO2, or dry chemical.

Возможный контакт

Occupational exposure to asphalt fumes can occur during the transport, storage, production, handling, or use of asphalt. The composition of the asphalt that is produced is dependent on the refining process applied to the crude oil, the source of the crude oil and the penetration grade (viscosity) and other physical characteristics of the asphalt required by the consumer. The process for production of asphalt is essentially a closed-system distillation. Refinery workers are therefore potentially exposed to the fumes during loading of the asphalt for transport from the refinery during routine maintenance, such as leaning of the asphalt storage tanks, or during accidental spills. Most asphalt is used out of doors, in paving and roofing. The workers’ exposure to the fumes is dependent on environmental conditions, work practices, and other factors. These exposures are stated to be generally intermittent and at low concentrations. Workers are potentially exposed also to skin and eye contacts with hot, cut-back, or emulsified asphalts. Spray application of cut-back, or emulsified asphalts may involve respiratory exposure also.

Перевозки

UN1999 Tars, liquid including road oils and cutback bitumens, Hazard Class: 3; Labels: 3-Flammable liquid.

Несовместимости

Asphalt and bitumen dust may form explosive mixture with air. Note: Asphalt becomes molten at about 93 C. Asphalt burns readily when heated or ignited in the presence of air or oxygen. May be incompatible with strong oxidizing agents like nitric acid. Charring may occur followed by ignition. If heated sufficiently or ignited in the presence of air, oxygen or strong oxidizing agents, can burn exothermically. May be ignited by strong oxidizing agents. Mostly unreactive in other settings. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.

Утилизация отходов

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed. Asphalt solids may be landfilled.