1.1 What are nitrophenols? |
1.2 How might I be exposed to nitrophenols? |
1.3 How can nitrophenols enter and leave
my body? |
1.4 How can nitrophenols affect my health? |
1.5 Is there a medical test to determine
whether I have been exposed to nitrophenols? |
1.6 What recommendations has the federal
government made to protect human health? |
1.7 Where can I get more information? |
References |
|
|
|
July 1992 |
Public Health Statement |
for |
Nitrophenols |
|
CAS#
|
2-Nitrophenol 88-75-5 |
|
4-Nitrophenol 100-02-7 |
|
|
This Public Health Statement is the
summary chapter from the Toxicological
Profile for nitrophenols. It is one in a series of Public
Health Statements about hazardous substances and their health
effects. A shorter version, the ToxFAQs™,
is also available. This information is important because this
substance may harm you. The effects of exposure to any hazardous
substance depend on the dose, the duration, how you are exposed,
personal traits and habits, and whether other chemicals are
present. For more information, call the ATSDR Information
Center at 1-888-422-8737.
|
|
|
This Statement was prepared to give you
information about 2-nitrophenol and 4-nitrophenol and to emphasize
the human health effects that may result from exposure to
them. The Environmental Protection Agency (EPA) has identified
1,177 National Priorities List (NPL) sites. Nitrophenols have
been found at 14 of these sites. However, we do not know how
many of the 1,177 NPL sites have been evaluated for 2-nitrophenol
and 4-nitrophenol. As EPA evaluates more sites, the number
of sites at which nitrophenols are found may change. This
information is important for you because nitrophenols may
cause harmful effects and because these sites are potential
or actual sources of human exposure to 2-nitrophenol and 4-nitrophenol.
When a chemical is released from a large
area, such as an industrial plant, or from a container, such
as a drum or bottle, it enters the environment as a chemical
emission. This emission, which is also called a release, does
not always lead to exposure. You can be exposed to a chemical
only when you come into contact with it. You may be exposed
to it in the environment by breathing, eating, or drinking
substances containing the chemical, or from skin contact with
it.
If you are exposed to a hazardous substance
such as nitrophenols, several factors will determine whether
harmful health effects will occur and what the type and severity
of those health effects will be. These factors include the
dose (how much), the duration (how long), the route or pathway
by which you are exposed (breathing, eating, drinking, or
skin contact), the other chemicals to which you are exposed,
and your individual characteristics such as age, sex, nutritional
status, family traits, life style, and state of health.
|
|
1.1
What are nitrophenols? |
The two nitrophenols are very similar
in their chemical properties. The manufacture of one almost
always produces at least a little of the other. Therefore,
we include them both in one profile. 2-Nitrophenol is a light
yellow solid with a peculiar aromatic smell. 4-Nitrophenol
is a colorless to light yellow solid with very little odor.
2-Nitrophenol is slightly soluble in cold water, but 4-nitrophenol
is moderately soluble in cold water. Neither chemical evaporates
at room temperature. These are man-made chemicals with no
evidence of their formation from any natural source. Therefore,
humans are solely responsible for the presence of the chemicals
in the environment. The main sources of the two chemicals
are industrial manufacturing and processing. 2-Nitrophenol
is used mainly to produce dyes, paint coloring, rubber chemicals,
and substances that kill molds (fungicides). 4-Nitrophenol
is used mainly to manufacture drugs, fungicides, and dyes,
and to darken leather. The time needed for these two chemicals
to disappear chemically in air is not known. They both break
down (degrade) in water and surface soil, but the breakdown
takes longer at lower soil depths and in groundwater. Therefore,
they are expected to stay longer in the deep soil of dump
sites compared to surface soil and may even stay indefinitely
in these soils
|
back to top |
|
1.2
How might I be exposed to nitrophenols? |
Small amounts of the two substances can
be found in the air, water, and soil. Therefore, breathing
air, drinking water, and eating foods grown in soils that
contain these substances can expose you to them. The background
levels (when no apparent sources of pollution are present)
of the two nitrophenols in air are not known. However, in
one case, the level of 2-nitrophenol in the air in Portland,
Oregon, was 4 parts per trillion (ppt by volume). Its level
in the air in Dubendorf, Switzerland, was 61 ppt. These are
very small numbers, and exposure from breathing air containing
such low levels of these substances may not be very harmful.
Except for one case of polluted water, these two substances
have not been found in U.S. public drinking waters. The background
levels of these compounds in foods eaten by humans are not
known either. Because the chemicals break down rapidly, any
exposure from these levels will be small. 4-Nitrophenol has
been found in the urine of people who did not have any known
exposure to this substance. The 4-nitrophenol found in human
urine comes from the breakdown within the body of a pesticide,
parathion, that is commonly used on certain agricultural products
that many of us eat.
Some people may be exposed to higher
than background levels of nitrophenols. Workers who produce
or process these chemicals may be exposed to higher doses,
particularly during spills or accidents. Workers involved
in cleaning up hazardous waste or spills that contain these
chemicals and pesticide applicators are especially subjected
to higher than background levels of exposure. People who use
certain pesticides or who drink well water near farming areas
where certain pesticides are used may also be exposed to higher
than background levels of 4-nitrophenol. The two nitrophenols
and their mixture have been found in at least 14 of the 1,177
hazardous waste sites on the National Priorities List (NPL).
People who live near these sites may be subjected to exposure
at higher doses than background. Except for the high levels
of 4-nitrophenol found in the urine of persons exposed to
the pesticide, parathion, we have no evidence of exposure
to 2-nitrophenol and 4-nitrophenol that is higher than background
levels.
|
back to top |
|
1.3
How can nitrophenols enter and leave my body? |
2-Nitrophenol and 4-nitrophenol can enter
your body through your lungs and pass into the blood stream
if you breathe contaminated air. If you swallow 2-nitrophenol
or 4-nitrophenol, most of it probably enters your body and
passes from the stomach into the blood stream very quickly
(in minutes). If you spill 2-nitrophenol or 4-nitrophenol
on your skin, some of it might pass through the skin into
the blood stream, but we do not know how much or how fast.
Once inside your body, 2-nitrophenol and 4-nitrophenol change
(we call this change metabolism) into other chemicals that
will be quickly (in hours) released from the body in your
urine. We do not have enough information available to determine
which will be the most likely way that 2-nitrophenol or 4-nitrophenol
will enter your body if you are exposed at hazardous waste
sites.
|
back to top |
|
1.4
How can nitrophenols affect my health? |
How a chemical affects your health depends
on how much you are exposed to and for how long. As the level
and length of your exposure increase, the effects are likely
to become more severe. Rats that breathed dusts of 4-nitrophenol
for 2 weeks developed a blood disorder which reduces the ability
of the blood to carry oxygen to tissues and organs. However,
these abnormalities disappeared a few days after exposure
stopped. Chemicals like the nitrophenols cause a similar blood
disorder in humans, and so humans exposed for weeks or longer
to high levels of nitrophenols may develop the same types
of blood disorders that animals do. Experimental studies have
shown that 4-nitrophenol is more harmful than 2-nitrophenol
in animals. There is no information on the effects on human
health from breathing dusts of 2-nitrophenol or 4-nitrophenol.
Some rats, mice, and rabbits that swallowed
large amounts of 2-nitrophenol or 4-nitrophenol died within
a few days, but we do not know the exact cause of death. Some
rats that swallowed smaller amounts of 4-nitrophenol for a
few weeks also died, but those that survived had no apparent
harmful health effects. No birth defects were found in the
offspring of pregnant mice that swallowed 4-nitrophenol. We
do not know if swallowing very small amounts of 2-nitrophenol
or 4-nitrophenol for many months or years leads to serious
disease or death. There is no information on their health
effects from humans who ate food or drank water contaminated
with these chemicals.
Rats and rabbits that had relatively
large amounts of 4-nitrophenol applied to their skin for a
day or less had skin irritation. Rats that had a small amount
of 4-nitrophenol on their skin for a few months also had skin
irritation. 4-Nitrophenol also caused eye irritation in rabbits
when it was applied to the eye. It appears that exposure of
animals to very small amounts of 2-nitrophenol or 4-nitrophenol
by skin contact for many months does not lead to serious disease
or death. We do not know whether breathing dusts of these
chemicals or spilling them on your skin can cause birth defects,
affect fertility, or cause cancer.
|
back to top |
|
1.5
Is there a medical test to determine whether I have been exposed
to nitrophenols? |
Although methods are available for measuring
levels of 4-nitrophenol in the urine and blood, they are probably
not useful unless the exposure was very recent. 4-Nitrophenol
passes out of the body through urine within a few hours. Because
the effects usually seen on the blood may also result from
causes besides 4-nitrophenol, these effects alone cannot be
used to prove exposure. No tests are available to tell whether
you have been exposed to 2-nitrophenol.
|
back to top |
|
1.6
What recommendations has the federal government made to protect
human health? |
In order to minimize exposure to nitrophenols
by humans the Environmental Protection Agency (EPA) says that
industry must tell the National Response Center when 100 pounds
or more of 2-nitrophenol or 4-nitrophenol have been disposed
of.
|
back to top |
|
1.7
Where can I get more information? |
If you have any more questions or concerns, please contact
your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Information line and technical assistance:
Phone: 888-422-8737
FAX: (770)-488-4178
ATSDR can also tell you the location of occupational and environmental health
clinics. These clinics specialize in recognizing, evaluating, and treating illnesses
resulting from exposure to hazardous substances.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
|
back to top |
|
References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1992. Toxicological
profile for nitrophenols. Atlanta, GA: U.S. Department
of Health and Human Services, Public Health Service.
|
back to top |
|
|
|