1.1 What is hydraulic fluid? |
1.2 What happens to hydraulic fluid when
it enters the environment? |
1.3 How might I be exposed to hydraulic
fluid? |
1.4 How can hydraulic fluid enter and
leave my body? |
1.5 How can hydraulic fluid affect my
health? |
1.6 Is there a medical test to determine
whether I have been exposed to hydraulic fluid? |
1.7 What recommendations has the federal
government made to protect human health? |
1.8 Where can I get more information? |
References |
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September 1997 |
Public Health Statement |
for |
Hydraulic Fluid |
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CAS#
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55957-10-3; 68937-40-6; 50815-84-4; 55962-27-1;
66594-31-8; 63848-94-2; 107028-44-4; 28777-70-0 |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for hydraulic fluid. 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.
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This public health statement tells you
about hydraulic fluids and the effects of exposure.
The Environmental Protection Agency (EPA)
identifies the most serious hazardous waste sites in the nation.
These sites make up the National Priorities List (NPL) and
are the sites targeted for long-term federal cleanup.
Hydraulic fluids have been found in at least 10 of the 1,428
current or former NPL sites. However, it's unknown how
many NPL sites have been evaluated for these substances.
As more sites are evaluated, the sites with hydraulic fluids
may increase. This is important because exposure to these
substances may harm you and because these sites may be sources
of exposure.
When a substance 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. This
release does not always lead to exposure. You are exposed
to a substance only when you come in contact with it.
You may be exposed by breathing, eating, or drinking the substance
or by skin contact.
If you are exposed to hydraulic fluids,
many factors determine whether you'll be harmed. These
factors include the dose (how much), the duration (how long),
and how you come in contact with it. You must also consider
the other chemicals you're exposed to and your age, sex, diet,
family traits, lifestyle, and state of health.
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1.1
What is hydraulic fluid? |
Hydraulic fluids are a very large class
of materials that are used in machines and equipment to transfer
pressure from one point to another. They are used in
many ways including all fluids for car automatic transmissions,
brakes, and power steering. Hydraulic fluids are also
used in many machines like tractors and other farm equipment,
forklift trucks, bulldozers, and other construction equipment,
and airplanes. In industry, hydraulic fluids are used
in machines that push, lift, pull, turn, and hold things.
This profile covers only three of the many types of hydraulic
fluids: (1) mineral oil, (2) organophosphate ester,
and (3) polyalphaolefin. These types are among the most
commonly used today. The trade names of typical hydraulic
fluids covered in this profile include Durad®, Fyrquel®,
Skydrol®, Houghton-Safe®, Pydraul®, Reofos®,
Reolube®, and Quintolubric®. Hydraulic fluids
used in cars are not specifically covered in this profile.
Some hydraulic fluids have a bland oily
smell, while others have no smell. Mineral oil and polyalphaolefin
hydraulic fluids are mixtures that have oil in them and will
burn. Oil-in-water hydraulic fluids (a special type
of mineral oil hydraulic fluid) do not burn because they contain
water. Organophosphate ester hydraulic fluids are mostly
made without oil and will not burn unless there is a flame
directly on them; once the flame is removed, these fluids
will stop burning. Because they do not burn, organophosphate
ester hydraulic fluids are used in airplanes and other places
where fires are very undesirable.
Mineral oil hydraulic fluids are produced
from crude oil. Organophosphate ester and polyalphaolefin
hydraulic fluids are manufactured. All hydraulic fluids
contain many ingredients which reduce wear, make the fluid
flow better, and make it thinner when it is cold. More
than 200 million gallons of hydraulic fluids are sold each
year in the United States.
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1.2
What happens to hydraulic fluid when it enters the environment? |
Hydraulic fluids can enter the environment
from spills and leaks in machines that use them and from leaky
storage tanks. If spilled on soil, some of the ingredients
in the hydraulic fluids mixture may stay on the top, while
others may sink into the groundwater. How fast the ingredients
move through soil depends on many things. These include
how much is spilled, how much rain falls on the spill, and
the type of soil (for example, hydraulic fluids will move
quickly in sandy soil, but will move slower in heavy clay).
In water, some ingredients of hydraulic fluids will transfer
to the bottom and stay there. Fish may contain some
hydraulic fluid ingredients if they live near places that
make or use a lot of it. Eventually, the ingredients
of hydraulic fluids are degraded in the environment, but complete
degradation may take more than a year. Scientists know
a little about how some of the ingredients in hydraulic fluids
break down in the environment, but they know almost nothing
about how toxic these breakdown products are.
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1.3
How might I be exposed to hydraulic fluid? |
Exposures to hydraulic fluids occur mainly
in workers using hydraulic equipment and in people who work
on cars or tractors that use the fluids. Most people
are exposed when fluids spill or leak on the skin, when the
fluid is changed, or when the fluid reservoirs are filled.
Low levels of hydraulic fluids may occur in the air near machines
that use them. Understanding environmental levels of
hydraulic fluids is very difficult because the ingredients
in hydraulic fluids are used in many products other than hydraulic
fluids. For example, mineral oil is an ingredient in
both motor oil and mineral oil hydraulic fluids. In
the environment, mineral oil from both sources would appear
to be the same. Polyalphaolefin hydraulic fluids have
chemical components and potential applications similar to
mineral oil hydraulic fluids.
The ingredients in organophosphate ester
hydraulic fluids also have many uses, but are usually not
detected in the environment. They do not have as many
uses as mineral oils and polyalphaolefins. When detected,
concentrations of organophosphate esters range from 1 to 20
parts per billion (ppb) in water, 0.0002 to 1.31 ppb in drinking
water, and less than 100 to greater than 6,300,000 ppb in
sediments. In general, organophosphate esters are found
near places where they are manufactured. People most
likely to be exposed to hydraulic fluids include car, truck,
tractor, industrial equipment, and airplane mechanics and
repair technicians, and maintenance workers in heavy industry
like car assembly plants, foundries, steel mills, paper mills,
and plants that manufacture appliances or other large or small
household or commercial items. Polyalphaolefin hydraulic
fluids are often used in military equipment.
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1.4
How can hydraulic fluid enter and leave my body? |
Very little is known about how mineral
oil hydraulic fluids, polyalphaolefin hydraulic fluids, and
organophosphate ester hydraulic fluids enter and leave your
body. Some information exists about how some of the
chemical components in the organophosphate ester hydraulic
fluids enter and leave your body.
We know that chemical components of mineral
oil hydraulic fluids can enter the body if you swallow them
or they come in contact with your skin because health effects
have occurred in people after they swallowed or had prolonged
skin contact with certain mineral oil hydraulic fluids.
Health effects have occurred in animals after they breathed,
swallowed, or had skin contact with organophosphate ester
hydraulic fluids. We do not know if mineral oil hydraulic
fluids or polyalphaolefin hydraulic fluids will enter your
body from your lungs if you breathe them as vapor or oil mist.
We know that some chemical components
of organophosphate ester hydraulic fluids can enter your body
from your lungs if you breathe them. Some organophosphate
esters rapidly enter your body. Certain components of
organophosphate ester hydraulic fluids are found in blood
and urine within 1 hour of having them on your skin.
Within 6 hours after animals swallow large amounts of certain
components of organophosphate ester hydraulic fluids, they
enter the blood and are found throughout the body, especially
in fat. Organophosphate esters leave the body in the
urine and feces within several days.
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1.5
How can hydraulic fluid affect my health? |
This toxicological profile discusses
only three classes of hydraulic fluids: mineral oil
hydraulic fluids, polyalphaolefin hydraulic fluids, and organophosphate
ester hydraulic fluids. The classes are based on the
major chemicals found in the hydraulic fluids. However,
hydraulic fluids are often complex mixtures of many chemical
components. A particular hydraulic fluid can differ
in its chemical components from another hydraulic fluid even
if the two fluids are in the same class. Thus, effects
of exposure may differ.
Very little is known about how mineral
oil hydraulic fluids and polyalphaolefin hydraulic fluids
will affect your health. There are reports of health
effects in people exposed to these classes of hydraulic fluids.
After drinking mineral oil hydraulic fluid, a child developed
pneumonia and bleeding in the intestines and then died.
A man whose hands and forearms were heavily exposed to mineral
oil hydraulic fluids in his job developed weakness in his
hands. This effect was probably caused by one of the
organophosphate ester additives of the mineral oil hydraulic
fluid. The skin and eyes of animals were red and swollen
after contact with certain mineral oil hydraulic fluids and
polyalphaolefin hydraulic fluids. Animals breathing
very high levels of polyalphaolefin hydraulic fluids became
drowsy and had congested lungs and trouble breathing.
We do not know if mineral oil hydraulic fluids or polyalphaolefin
hydraulic fluids will cause birth defects, reproductive effects,
or cancer.
There have been reports of people being
poisoned from swallowing cooking oil or medicines contaminated
with organophosphate esters. Outbreaks of brain, nerve,
and muscle problems due to organophosphate contamination have
happened in the United States and other countries. If
you get certain organophosphate ester hydraulic fluids on
your skin, it may be irritated and turn red. There are
no reports of people breathing or swallowing this type of
fluid. Studies in animals suggest that if you breathe
or swallow large amounts of certain organophosphate ester
hydraulic fluids, you may have nervous system problems.
Certain organophosphate ester hydraulic fluids affect the
nervous system of animals in two different ways. The
first type of effect occurs within a few hours of breathing,
swallowing, or skin contact. The organophosphate ester
part of the hydraulic fluid rapidly inhibits the activity
of important enzymes in the nervous system causing multiple
symptoms including tremors, sweating, diarrhea, and difficulty
breathing. The second effect involves damage to nerves.
The symptoms of this type of damage are general weakness,
weakness of the arms and legs, and paralysis. These
symptoms of nerve damage can occur several weeks after exposure
has stopped. If you have been exposed once to organophosphate
ester hydraulic fluids, the symptoms of enzyme inhibition
will disappear before the weakness occurs. Not all types
of these fluids cause both types of nervous system damage.
In animal studies, not all animals that have symptoms of enzyme
inhibition have nerve damage. Both of these types of
nervous system damage can occur after one or several exposures.
Cows eating grass containing organophosphate
ester hydraulic fluid had difficulty producing milk for their
young. We do not know if this will also occur in people.
We do not know if organophosphate ester hydraulic fluids will
cause birth defects, affect fertility, or cause cancer.
The Department of Health and Human Services
(DHHS), the International Agency for Research on Cancer (IARC),
and EPA have not classified mineral oil hydraulic fluids,
polyalphaolefin hydraulic fluids, and organophosphate ester
hydraulic fluids for carcinogenic effects.
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1.6
Is there a medical test to determine whether I have been exposed
to hydraulic fluid? |
Hydraulic fluids themselves cannot be
measured in blood, urine, or feces, but certain chemicals
in them can be measured. Aliphatic hydrocarbons, which
are major components of mineral oil hydraulic fluids and polyalphaolefin
hydraulic fluids, can be detected in the feces. Certain
components of organophosphate ester hydraulic fluids leave
the body in urine. Some of these fluids inhibit the
enzyme cholinesterase. Cholinesterase activity in blood
can be measured. Because many other chemicals also inhibit
cholinesterase activity in blood, this test is not specific
for organophosphate ester hydraulic fluids. This test
is not available at most doctor's offices, but can be arranged
at any hospital laboratory.
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1.7
What recommendations has the federal government made to protect
human health? |
Federal government recommendations exist
to protect people's health from mineral oil hydraulic fluids.
Mineral oil is the major chemical component
of mineral oil hydraulic fluids. Mineral oil belongs to a
larger class of chemicals called petroleum distillates. The
Occupational Safety and Health Administration (OSHA) regulates
petroleum distillate and mineral oil mist levels in workplace
air. The occupational exposure limits for an 8-hour workday,
40-hour workweek are 2,000 milligrams per cubic meter (mg/m³)
in air for petroleum distillates and 5 mg/m³ for mineral
oil mists. The National Institute for Occupational Safety
and Health (NIOSH) recommends an exposure limit of 350 mg/m³
of petroleum distillates for a 10-hour workday, 40-hour workweek.
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1.8
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
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1997. Toxicological
profile for hydraulic fluid. Atlanta, GA: U.S. Department
of Health and Human Services, Public Health Service.
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