Solvents can be defined as liquids that dissolve other
materials or are used to make evenly dispersed mixtures. Water
is an extremely common solvent. The advantages of using water as
a solvent include the facts that it is inexpensive, easy to
dispose of, and nontoxic.
Soap and water solutions can be used
for many cleanup jobs.
If one wants to clean, dissolve, or thin materials that are
not soluble in water, organic solvents must usually be used.
These types of solvents can dissolve grease, dirt, resins, oils,
varnish and other materials; they are used to thin paints,
varnishes, and lacquers; to clean pieces of art, tools, brushes,
work surfaces, and even, unfortunately, hands.
solvents include kerosene, acetone, turpentine, toluene, ethyl
alcohol, etc. Mixtures of solvents are also common, for example
lacquer thinners, mineral spirits, naphthas, and petroleum
Solvents are ubiquitous in our lives.
They thin oil paints,
and are found in some drawing and printing inks, wood preparation
and finishes, photography and plastics materials.metal cleaners,
and some adhesives. Most commercial art products contain
solvents. Those who work in the performing arts use solvents are
in prop, scene and set fabrication, dressing, and cleanup.
Solvents are found in hair sprays and costume products, fabric
finishes, and some theatrical fogs. Ballet dancers spray pointe
shoes with solvent products, and musicians clean instruments with
Composition of Solvents
Solvents can have unique chemical structures or can be
mixtures of chemicals.
For example, acetone is a unique
chemical, whereas mineral spirits is a mixture of several
solvents in the same boiling range. Each chemical is assigned a
Chemical Abstract Number (CAS #) which identifies it. In some
instances CAS Numbers are also assigned to well known mixtures
like mineral spirits. Solvents can come in different grades of
purity, and can sometimes be contaminated with small amounts of
other solvents in the manufacturing process.
If purity is of
concern, then it is important to get your solvents from a source
that will give detailed information on contents.
The names of solvents can also vary. For example, methyl
alcohol and methanol are chemical names for one solvent, and
1,1,1-trichloroethane and methyl chloroform are chemical names
for another solvent. Solvents can also have other synonyms, for
example wood alcohol is a synonym for methyl alcohol. Hawley's
Condensed Chemical Dictionary and the NIOSH Registry of Toxic
Effects of Chemical Substances (RTECS), are good sources of
information on synonyms.
Unfortunately, a solvent or solvent mixture can also be sold
by a product name or trade name which gives no information about
its composition. Lacquer thinners from different manufacturers,
for example, can have entirely different compositions.
Similarly, trade names such as Varsol do not give information
about the composition. The Material Safety Data Sheet for such
products should list the hazardous ingredients in the trade name
Another problem with trade name products is that their
composition can change without warning since manufacturers often
change the composition of their solvent formulations based on the
availability and price of the various components. Therefore,
these materials may then produce variable results and have an
Solvents can vary widely in their volatility, with low boiling
point solvents being much more volatile. This means that large
amounts can evaporate into the air in short periods of time. The
accumulation of solvent vapors in the workspace air can become
both a health and a fire risk.
The volatility of a solvent is best indicated by its vapor
pressure (vp), the pressure that the vapors, generated by
evaporation of the liquid, exert upon the atmosphere above the
liquid. The higher the vapor pressure, the more volatile the
liquid, and the more easily it evaporates at room temperatures.
For example, acetone, which has a vapor pressure of 150 mm of
mercury at room temperature and standard atmospheric pressure,
evaporates quicker than methyl ethyl ketone with a vapor pressure
of 71 mm.
The volatility of solvents increases when their temperature is
increased. Solvents should be heated only with caution and
contact with hot surfaces and ignition sources must be prevented.
Knowing the exact chemical ingredients of the solvents and
other materials that you work with will enable you to determine
their toxicity. If the ingredient information is not adequately
provided on the label, one can request a Material Safety Data
Sheet (MSDS) from the manufacturer or distributor of the solvent.
A general indication of the material's toxicity is its
Threshold Limit Value (TLV), which is established by the American
Conference of Governmental Industrial Hygienists (ACGIH).
TLV of a substance is the airborne concentration of a substance
to which nearly all workers can be exposed repeatedly day after
day without adverse effects. TLVs are expressed as parts of the
substance per million parts of air (ppm) or as milligrams of the
substance per cubic meter of air (mg/m3), averaged over an 8-hour
day. For example, the TLV of xylene is 100 ppm or 434 mg/m3.
For substances that are highly irritating, highly toxic, or that
have immediate effects, Short Term Exposure Limits (STEL) are
also used. The STEL of a substance is the allowable average
concentration measured over a 15 minute interval. For example,
while the TLV for xylene is 100 ppm, its STEL is 150 ppm.
means that the average concentration of xylene over an 8-hour
period should not exceed 100 ppm, and that during any 15 minute
period should not exceed an average of 150 ppm. Sometimes a TLV
has a C assigned to it, indicating the TLV is a ceiling
concentration which must not be exceeded at any time.
Generally, substances with TLVs at or below 100 ppm are
considered highly toxic. Between 100 ppm and 500 ppm is
considered moderately toxic, and above 500 ppm, slightly toxic.
Remember that TLVs are advisory, and should just be used as a
guide for further evaluation of chemicals in your materials.
In contrast to the voluntary TLVs, the Occupational Safety and
Health Administration (OSHA) has set Permissible Exposure Limits
(PELs), which are similar in definition to TLVs, but are
mandatory and enforceable. Most PELs are similar to the 1988
TLVs. Table 1 lists TLVs of common solvents, unless the PEL for
a particular solvent is lower.
The National Institute for Occupational Safety and Health
(NIOSH) has established Recommended Exposure Limits (RELs) for
many chemicals, based on its research. NIOSH RELs are usually
lower than either TLVs or PELs.
For carcinogens, NIOSH also
recommends reducing exposure to the lowest feasible
Although some solvents are less hazardous than others, all
solvents can cause toxic effects. There are no safe organic
solvents, only more and less toxic ones. All organic solvents
can affect the nervous system, respiratory system, skin, eyes,
and internal organs to some degree. Solvents are also implicated
in damage to both the male and the female reproductive systems.
Table 1 lists the toxic properties of common solvents.
Solvents can damage the skin in three ways: by drying, by
irritation, and by sensitization. Solvents can dissolve the
skin's natural protective barrier of oils and waxes to cause
drying, defatting, cracking, and fissuring of the skin.
also irritate the skin to cause reddening and inflammation. Most
solvents cause these symptoms in people with sufficient
exposure. Some solvents are sensitizers, and can cause allergic
reactions, for example, turpentine.
In addition, many solvents can penetrate the skin, enter the
bloodstream, and cause injury to internal organs.
skin-penetrating solvents are dimethyformanide (DMF), glycol
ethers, toluene, xylene, and methyl alcohol.
Brain and Nervous System Damage
The most commonly experienced symptom of solvent vapor
inhalation is narcosis (dizziness, light-headedness,
irritability, fatigue, headaches, sleepiness, loss of
coordination, nausea, etc.). These symptoms are produced by
solvent dissolved in the bloodstream acting directly on the brain
to depress the central nervous system (CNS). The effect is
similar to alcohol intoxication.
These effects are usually
reversible if exposure to the solvent is discontinued. However,
if exposure is high enough, further CNS depression can lead to
unconsciousness and death. Solvent-exposed individuals operating
machinery are at a higher risk of accidents because of decreased
coordination and fatigue.
Studies over the last decade have shown that repeated heavy
solvent exposure over several years may cause permanent brain
damage, called chronic toxic encephalopathy. Symptoms can
include memory loss, behavioral changes, emotional lability,
confusion, inability to concentrate, neurological and personality
changes, and problems with manual dexterity.
implicated in most studies are the chlorinated hydrocarbons,
aromatic hydrocarbons, and aliphatic hydrocarbons (see chart).
Repeated exposure to some solvents can also temporarily damage
the peripheral nervous system (PNS), which is the system of
nerves leading from the spinal cord to the rest of the body.
Symptoms include numbness and tingling sensations, difficulty in
grasping objects, loss of ankle reflexes, weakness, and in severe
cases, paralysis of the arms and legs. Methyl butyl ketone
(MBK), n-hexane, and carbon disulfide are solvents known to cause
this effect. N-hexane is commonly found in spray adhesives,
spray fixatives, rubber cements and rubber cement thinners,
contact adhesives, some lacquer thinners, cleaning and sanitizing
agents, and in low-boiling naphthas.
Most organic solvents can irritate the sensitive membranes of
the nose, throat, and eyes. Solvent concentrations that cause
this irritation may also damage lung tissue. Chemical pneumonia
may be caused by very high concentrations of irritating organic
solvents; however, such high levels are usually so offensive that
exposed individuals cannot tolerate the exposure. More commonly,
lower solvent doses are tolerated in the work environment and
after years of exposures, may cause chronic bronchitis.
Chemical pneumonia can also be caused by aspiration of aliphatic
and aromatic hydrocarbons in liquid form into the lungs, for
example from vomiting after ingestion of these solvents.
Damage to Internal Organs
Upon entering the bloodstream, solvents can be transported to
and injure specific internal organs and organ systems. This is
especially true for the liver and kidneys, since these organs are
often damaged during detoxification and elimination of solvents
from the body.
Chlorinated solvents, such as perchloroethylene and carbon
tetrachloride, are especially toxic to the liver and kidneys.
Chlorinated solvents, in general, are among the most hazardous
solvents, and should be avoided whenever possible. Chlorinated
solvents may form a highly toxic gas called phosgene, if heated
or if they come in contact with ultraviolet light.
The heart and circulatory system are also vulnerable to the
toxic effects of solvents.
Benzene and many glycol ethers can
damage the bone marrow and cause anemia. Benzene can also cause
Another solvent, methylene chloride, is metabolized into
carbon monoxide, which reduces the level of oxygen in the blood.
This exposure can cause heart attacks and especially endangers
people with pre-existing heart or lung impairment. Methylene
chloride also affects the heart by producing arrhythmias
(irregular beating) of the heart at high concentrations, which
can lead to heart attacks.
High concentrations of freons,
trichloroethylene, 1,1,1-trichlorethane, toluene and gasoline
have also caused arrhythmias resulting in heart attacks. If an
individual is susceptible to arrhythmias, then they could be at
risk at even lower concentrations than other people.
Although rare, fatalities from acute overexposures to some
solvents do occur, usually from heart and respiratory failure.One case study of furniture stripping in dip tanks reported two
separate fatalities from methylene chloride paint strippers.
victims were without respiratory protection or adequate local
exhaust ventilation. The concentration of a chemical necessary
to provoke an acute fatality is usually much higher than levels
found in normal, everyday exposures.
Certain solvents have been found to cause cancer. Benzene
causes cancer, (although the closely related solvent toluene does
not). Most chlorinated solvents, for example, are carcinogenic
in laboratory animals, and are probable human carcinogens.
include: carbon tetrachloride, chloroform, trichloroethylene,
perchloroethylene, and methylene chloride. Other probable human
carcinogens are dioxane and dimethylformamide.
Most organic solvents become potential fire hazards when they
evaporate, causing a build-up of flammable vapors. The National
Fire Protection Association (NFPA) classifies the flammability
and combustibility of liquids according to their flash points.
The flash point (fp) of a liquid is the lowest temperature at
which vapors will form an ignitable mixture in air at the
Any liquid will burn at or above its flash
point if a source of ignition is present. Refer to Table 2 for
the NFPA flammability classifications.
Class IA and IB liquids, such as acetone, toluene, and
gasoline, have flash points below normal room temperatures and
can start flash fires in the presence of a flame, spark, or even
static electricity. Class IC flammable liquids would burn on hot
days or if heated. Refer to the Table 1 for the flash points of
Table 2. NFPA Flammability Definitions
Flash point: below 73 degrees F (23degrees C)
Boiling point: below 100 F (38 C)
Flash point: below 73degrees F (23degrees C)
Boiling point: at or above 100degrees F (38degrees C)
Flash point: 73-100degrees F (23-38degrees C)
Boiling point: at or above 100degrees F (38degreesC)
Flash point: 100-140degrees F (38-60degrees C)
Flash point: 140-200degrees F (60-93degrees C)
Flash point: at or above 200degrees F (93degrees C)
Combustible liquids, such as kerosene, mineral spirits, and
cellosolves, with flash points at or above 100degrees F, are divided
into Classes II, IIIA, and IIIB. Although any combustible liquid
is a fire threat if heated, Class IIIB liquids generally cause
little concern as fire hazards because of their high flash
Not all arts and crafts materials, however, are labeled
according to NFPA requirements.
The Federal Hazardous Substances
Act (FSHA) regulates the flammability labeling of consumer
products, including many materials sold in art supply stores,
such as paint strippers, thinners, and aerosol sprays. Although
we recommend only NFPA flammability definitions for industrial
and professional use, it is important to be familiar with both
systems. The FSHA flammability definitions are in Table 3.
Table 3. FHSA Flammability Definitions
Hazard Category Flash point
Extremely flammable below 20degrees F (-7degrees C)
Flammable 20-80degrees F (-7-27degrees C)
Combustible 80-150degrees F (27-66degrees C).
Some solvents, such as ethyl ether, are too hazardous to be
used or stored safely in ordinary shops or studios. In addition,
ethyl ether, isopropyl ether, dioxane, and tetrahydrofuran absorb
oxygen from the air to form explosive peroxides. When containers
of these solvents containing small amounts of their peroxide
residues are heated (for example by storing them near a radiator
or in sunlight), they can be explosive. Friction from screwing
on the container lids of these solvents has been known to cause
explosions when peroxides had formed on the container lip.
1. Compile an inventory of all solvents and solvent-containing
materials. Label all containers, even small vials.
Material Safety Data Sheets (MSDS) on all products.
2. Use water-based materials whenever possible. This minimizes
inhalation problems. Note that some water-based materials
contain small amounts of solvents to dissolve resins.
3. Use the least toxic solvent possible. Substitute safer
solvents from the same class whenever possible. For example, use
heptane instead of hexane, and ethyl alcohol or isopropyl alcohol
instead of methyl alcohol.
4. Avoid breathing vapors. Dilution ventilation may be adequate
for exhausting small amounts of solvent. For large amounts of
solvents, or highly toxic solvents, use local exhaust ventilation
to capture the solvent vapors before they escape into the room
(for example, a laboratory hood, slot hood, or window exhaust fan
1-2 feet away at work level). See the CSA's book Ventilation for
more information. Cover containers when not in use.
5. Avoid skin contact. Wear suitable gloves whenever work brings
skin in contact with solvents. Make sure that the type of glove
material is appropriate for solvents used since the permeability
of different glove materials varies with the solvent. See CSA's
data sheet on Glove Selection for more information.
6. Avoid eye contact. Wear protective goggles when you pour
solvents or when an accidental splash is possible. Do not rely
on regular eyeglasses for protection. Do not wear contact
lenses. In case of eye contact, flush immediately with clean
running water for 15 minutes and seek medical attention. A
plumbed eyewash fountain should be readily accessible.
7. Wash hands with a mild soap and water after exposure to
solvents, and apply a skin moisturizer (avoid those with coloring
and fragrance). Never wash hands in solvents. Baby oil or
vegetable oils can remove paint from the skin.
8. Use self-closing oily waste cans to hold solvent-soaked rags.
These should be emptied daily.
9. Spill control materials, available from safety supply
distributors, should be kept on hand for cleaning up spills and
residues. Emergency procedures should be drafted in case of a
flammable solvent spill of more than a quart of liquid, because
of the severe health and fire risks from the evaporating solvent.
See the CSA Spill Control data sheet.
10. Whenever possible, try to reuse solvents by allowing solids
to settle, and decanting off the liquid. Filter if necessary.
11. Dispose of all waste solvents properly. Solvent wastes
should be collected and stored in approved safety disposal cans.
Chlorinated solvents must be stored separately from other
solvents. Never pour solvents down the drain. If large
quantities of waste solvents are generated, a licensed hazardous
waste disposal company should be contracted to remove them. In
some instances, it may be appropriate to allow very small amounts
(less than a pint) of solvent to evaporate inside an explosion-
proof laboratory hood, on the roof, or outside, providing that no
one is exposed to the solvent vapors.
1. Protect against fire and explosion. Follow all local and
federal codes for the use, handling, ventilation, and storage
of flammable liquids. Eliminate all ignition sources in the
area. Smoking should be strictly prohibited.
2. The workspace should be equipped with a sprinkler system and
appropriate fire extinguisher. Class ABC multi-purpose, dry
chemical fire extinguishers are generally recommended. Because
of the corrosive properties of the dry chemical, a combination of
a Class A and a Class BC carbon dioxide fire extinguisher may
also be used.
3. A pint or more of a flammable or combustible liquid should be
stored in an approved safety can. For dispensing small amounts
of liquids (e.g. for cleanup), use plunger cans.
4. Large quantities of flammable and combustible liquids should
be kept in approved flammable storage cabinets. Quantities over
60 gallons (including 55-gallon drums), should be stored only in
separate outside facilities or in a special storage room.
5. Use hand pumps when dispensing flammable liquids from either
5-gallon and 55-gallon metal drums, rather than tilting to pour.
The metal drum should be grounded, and metal receptacles should
be bonded to the drum with wire to prevent the buildup of static
6. Local exhaust ventilation systems handling flammable solvent
vapors, and electrical components in areas where flammable vapors
may be present, should be fire- and explosion-proof according to
the NFPA and National Electrical Code (NEC).
American Conference of Governmental Industrial Hygienists.
(1992). Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment. ACGIH, Cincinnati.
Hall, A.H., and Rumack, B.H. (1990). Methylene chloride exposure
in furniture stripping shops: Ventilation and respirator use
practices. J. Occup. Med. 32(1), 33-37.
Hawley, G. (Ed.) (1987). The Condensed Chemical Dictionary.
11th ed. Van Nostrand-Reinhold, New York.
Industrial Hygiene Subcommittee, Alliance of American Insurers.
(1986). Handbook of Organic Industrial Solvents. 6th ed.
Alliance of American Insurers, Chicago.
National Fire Protection Association. (1987). NFPA #30.
Flammable and Combustible Liquids Code. NFPA, Boston.
National Fire Protection Association. (1986). NFPA #45. Fire
Protection for Laboratories Using Chemicals. NFPA, Boston.
National Fire Protection Association. (1987). NFPA 70. National
Electrical Code. NFPA, Boston.
National Institute for Occupational Safety and Health.
(1990). Pocket Guide to Chemical Hazards. DHHS (NIOSH)
Publication No. 90-117, Government Printing Office,
Patty, F. (editor) (1981). Industrial Hygiene and Toxicology,
Vol. 2, 3rd edition. Interscience Publishers, New York.
FOR FURTHER INFORMATION
Written and telephoned inquiries about hazards in the arts
will be answered by the Art Hazards Information Center of the
Center for Safety in the Arts. Send a stamped, self-addressed
envelope for a list of our many publications. Permission to
reprint this data sheet may be requested in writing from CSA.
Write: Center for Safety in the Arts, 5 Beekman Street, Suite
1030, New York, NY 10038. Telephone (212) 227-6220.
This data sheet was prepared with assistance from the Kress
Foundation. CSA is partially supported with public funds from
the National Endowment for the Arts, the New York State Council
on the Arts, the New York City Department of Cultural Affairs,
and the NYS Department of Labor Occupational Safety and Health
Training and Education Program.
(c) Copyright Center for Safety in the Arts 1985, 1992.