Table 7
General Health Information About Benzene
| What is benzene? |
| Benzene is a clear, colorless liquid with a pleasant, sweet
odor. It evaporates into air very quickly. The odor of
benzene does not provide adequate warning of its hazard. |
| In this chapter, "benzene " means: |
| – |
Liquid benzene, benzene vapor, and benzene in
liquid mixtures and the vapor released by these
liquids. The CAS Registry Number that identifies
benzene is 71-43-2. |
| Synonyms for benzene include: Benzol, benzole, coal
naphtha, cyclohexatriene, phenyl hydride, pyrobenzol. |
| Benzin, petroleum benzin, and benzine are chemicals that
do not contain benzene. |
| How am I exposed to benzene? |
| Benzene exposure occurs when you: |
| – |
Breath in (inhale) vapor or liquid particles (from
actions such as spraying or splashing) containing
benzene; |
| – |
Have skin or eye contact with liquid or vapor
containing benzene. Benzene is absorbed through
the skin. Absorption occurs more rapidly with
abraded skin or when benzene is present in
solvents (as an ingredient or contaminant) which
are readily absorbed; |
| – |
Swallow (ingest) benzene. |
| What happens after I'm exposed to benzene? |
| Some benzene that enters your body will be absorbed
into the bloodstream. Once in the bloodstream, benzene
travels throughout your body and can be temporarily
stored in the bone marrow and fat. |
| Benzene is converted to products, called metabolites, in
the liver and bone marrow. Some of the harmful effects of
benzene exposure are caused by these metabolites. |
| Most of the metabolites of benzene leave the body in the
urine within 48 hours after exposure. |
| Why is medical monitoring necessary? |
| Medical monitoring is necessary to detect changes in
your body's blood-forming system, including the bone
marrow. These changes can occur due to repeated or
prolonged, unprotected exposure to benzene, even at
relatively low concentrations. Such changes can lead to
various blood disorders, ranging from anemia to
leukemia, an irreversible, fatal disease. Many of these
disorders may occur without symptoms. |
| Benzene is classified as a confirmed human carcinogen
(Group 1) by the International Agency for Research on
Cancer (IARC). |
| To learn more about the medical monitoring process, see
Medical evaluation, WAC 296-849-12030. |
| What health effects are linked to benzene exposure? |
| Unprotected exposure to benzene is associated with
various health effects including symptoms and diseases
associated with either short-term (acute) exposure or
long-term exposure (chronic). |
| Acute effects from inhaling high vapor concentrations: |
| An initial stimulatory effect on the central nervous
system (brain and spinal cord) can occur, characterized
by exhilaration, nervous excitation (irritability), and/or
giddiness. This may be followed by a period of
depression, drowsiness, or fatigue. |
| Headache, dizziness, nausea, or a feeling of intoxication
may develop. |
| A sensation of tightness in the chest may occur,
accompanied by breathlessness. Ultimately the victim
may lose consciousness. |
| In severe inhalation cases, tremors, convulsions, and
death may follow due to respiratory paralysis or
circulatory collapse in a few minutes to several hours. |
| Acute effects from inhaling liquid benzene: |
| Aspiration of small amounts of liquid benzene
immediately causes pulmonary edema (excessive
accumulation of fluid in lung tissues) and hemorrhage of
pulmonary tissue. |
| Skin contact: |
| Direct contact may cause redness (erythema). |
| Benzene has a defatting action on skin. Repeated or
prolonged contact may result in any of the following: |
| – |
Primary irritation; |
| – |
Dry skin; |
| – |
Scaling dermatitis (inflammation); |
| – |
Development of secondary skin infections. |
| Effects on the eyes and mucous membranes: |
| Localized effects from vapor or liquid contact on the eye
are slight. High concentrations of benzene are irritating
to eyes (causing a stinging sensation) and mucous
membranes of the nose and respiratory tract. |
| Effects due to prolonged exposure: |
| The blood forming (hematopoietic) system is the main
target for benzene's toxic effects. These effects can vary
from anemia to leukemia, an irreversible, fatal disease.
Many of the toxic effects may occur without symptoms. |
| Most importantly, prolonged exposure to small
quantities of benzene vapor is damaging to the blood
forming system. This damage has occurred at
concentrations of benzene that may not cause irritation of
mucous membranes or unpleasant sensory effects. |
| Early signs and symptoms are varied and often not
readily noticed and nonspecific. These include: |
| – |
Subjective complaints of headache, dizziness, and
loss of appetite may precede or follow clinical
signs; |
| – |
Rapid pulse and low blood pressure, in addition to
a physical appearance of anemia, may accompany
a subjective complaint of shortness of breath and
excessive tiredness. |
| Other symptoms may occur as the condition progresses: |
| – |
Bleeding from the nose, gums, or mucous
membranes; |
| |
AND |
| – |
Development of purpuric spots (small bruises). |