ASPHALTUM

Description

Asphalt fumes are flammable when hot andmay contain hydrogen sulfide and human carcinogen, suchas benzo(a)pyrene and dibenz(a,h)anthracene. Fumes generated during the production or application of asphalt (a darkbrown to black cement-like substance manufactured by thevacuum distillation of crude petroleum oil). Molecularweight= variable 1000°2600; Boiling point= .300℃;Freezing/Melting point= 55°175℃; Flash point#10°225℃ (as a general rule, the more liquid the type ofasphalt, the lower the flashpoint; cutback ,10℃; typicalasphalt 225℃); Autoignition 5 .400℃. HazardIdentification (based on NFPA-704 M Rating System) (typical asphalt): Health 0, Flammability 1, Reactivity 0.However, asphalt cutback has a flammability rating of 3.Insoluble in water. Hazard Identification (based on NFPA-704 M Rating System): roofer’s flux and straight run residue: Health 0, Flammability 1, Reactivity 0.Asphalt fumes have been defined by NIOSH as the nimboseeffusion of small, solid particles created by condensationfrom the vapor state after volatilization of asphalt. In addition to particles, a cloud of fume may contain materials stillin the vapor state. The major constituent groups of asphaltare asphaltenes, resins, and oils made up of saturated andunsaturated hydrocarbons. The asphaltenes have molecularweights in the range of 1000°2600, those of the resins fallin the range of 370°500, and those of the oils is in the rangeof 290°630. Asphalt has often been confused with tarbecause the two are similar in appearance and have sometimes been used interchangeably as construction materials.Tars are, however, produced by destructive distillation ofcoal, oil or wood, whereas asphalt is a residue from fractional distillation or crude oil. The amounts of benzo(a)pyrene found in fumes collected from two different plantsthat prepared hot mix asphalt ranged from 3 to 22 ng/m3;this is approximately 0.03% of the amount in coke ovenemissions and 0.01% of that emitted from coal-burninghome furnaces.

Chemical properties

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).

The Uses of ASPHALTUM

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.

The Uses of ASPHALTUM

Asphalt fumes arise from asphalt used for road construction, roofing, and coating of construction materials and in association with the production of asphalt from petroleum; in asphalt-based paints

Definition

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.

Definition

A mixture of solid or semisolid hydrocarbons obtained from coal, oil, etc.

General Description

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.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

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.

Hazard

Irritant, skin sensitizer.

Health Hazard

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.

Fire Hazard

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

Flammability and Explosibility

Not classified

Industrial uses

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.

Safety Profile

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.

Potential Exposure

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.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, getmedical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit

storage

Color Code—Red: Flammability Hazard: Store ina flammable materials storage area. Prior to working withthis chemical you should be trained on its proper handlingand storage. Asphalt is normally shipped solid in steeldrums. Fumes are encountered only in asphalt meltingoperations. Wherever lighter or liquid forms of asphalt areused, handled, manufactured, or stored, use explosion-proofelectrical equipment and fittings. Sources of ignition, suchas smoking and open flames, are prohibited where thischemical is used, handled, or stored in a manner that couldcreate a potential fire or explosion hazard.

Shipping

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

Incompatibilities

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.

Waste Disposal

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.