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).
Uses
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.
Uses
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
A
mixture of solid or semisolid hydrocarbons
obtained from coal, oil, etc.
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.
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.
Toxics Screening Level
The initial risk screening level and secondary risk screening level (SRSL) for benzo(a)pyrene (B(a)P) are 6E-4 μg/m3 and 6E-3 μg/m3, respectively.
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.
