National
Institute for Occupational Safety and Health
Many people
using gasoline-powered tools such as high-pressure washers, concrete
cutting saws (walk-behind/hand-held), power trowels, floor buffers,
welders, pumps, compressors, and generators in buildings or semienclosed
spaces have been poisoned by carbon monoxide (CO). CO can rapidly
accumulate (even in areas that appear to be well ventilated) and
build up to dangerous or fatal concentrations within minutes. Examples
of such poisonings include the following:
- A farm owner
died of CO poisoning while using an 11-horsepower, gasoline-powered
pressure washer to clean his barn. He had worked about 30 minutes
before being overcome.
- A municipal
employee at an indoor water treatment plant lost consciousness
while trying to exit from a 59,000-cubic-foot room where he had
been working with an 8-horse-power, gasoline-powered pump. Doors
adjacent to the work area were open while he worked. His hospital
diagnosis was CO poisoning.
- Five workers
were treated for CO poisoning after using two 8 horse-power, gasoline-powered,
pressure washers in a poorly ventilated underground parking garage.
- A plumber
used a gasoline-powered concrete saw in a basement with open doors
and windows and a cooling fan. He experienced a severe headache
and dizziness and began to act in a paranoid manner. His symptoms
were related to CO poisoning.
These examples
show a range of effects caused by CO poisoning in a variety of work
settings with exposures that occurred over different time periods
and with different types of ventilation. Workers in areas with closed
doors and windows were incapacitated within minutes. Opening doors
and windows or operating fans does NOT guarantee safety. CO is a
dangerous poison. Operating gasoline-powered engines and tools indoors
is RISKY BUSINESS.
It is not widely
known that small gasoline-powered engines and tools present a serious
health hazard. They produce high concentrations of CO--a poisonous
gas that can cause illness, permanent neurological damage, and death.
Because it is colorless, odorless, and nonirritating, CO can overcome
exposed persons without warning. Often there is little time before
they experience symptoms that inhibit their ability to seek safety.
Prior use of equipment without incident has sometimes given users
a false sense of safety; such users have been poisoned on subsequent
occasions. Recommendations for preventing CO poisoning are provided
below for employers, equipment users, tool rental agencies, and
tool manufacturers.
All
Employers and Equipment Users Should:
- NOT allow
the use of or operate gasoline-powered engines or tools inside
buildings or in partially enclosed areas unless gasoline engines
can be located outside away from air intakes. Use of gasoline-powered
tools indoors where CO from the engine can accumulate can be fatal.
An exception to this rule might be an emergency rescue situation
in which other options are not available--and then only when equipment
operators, assisting personnel, and the victim are provided with
supplied-air respirators.
- Learn to
recognize the symptoms and signs of CO overexposure: headache,
nausea, weakness, dizziness, visual disturbances, changes in personality,
and loss of consciousness. Any of these symptoms and signs can
occur within minutes of usage.
- Always
place the pump and power unit of high-pressure washers outdoors
and away from air intakes so that engine exhaust is not drawn
indoors where the work is being done. Run only the high-pressure
wash line inside.
- Consider
the use of tools powered by electricity or compressed air if they
are available and can be used safely. For example, electric-powered
tools present an electrocution hazard and require specific precautions
for safety.
- If compressed
air is used, place the gasoline-powered compressor outdoors and
away from air intakes so that engine exhaust is not drawn indoors
where the work is being done.
- Use personal
CO monitors where potential sources of CO exist. These monitors
should be equipped with audible alarms to warn workers when CO
concentrations are too high.
Employers
Should Also:
- Conduct
a workplace survey to identify all potential sources of CO exposure.
- Educate
workers about the sources and conditions that may result in CO
poisoning as well as the symptoms and control of CO exposure.
- Always
substitute less hazardous equipment if possible. Use equipment
that allows for the placement of gasoline-powered engines outdoors
at a safe distance from air entering the building.
- Monitor
employee CO exposure to determine the extent of the hazard.
Equipment
Users Should Also:
- Substitute
less hazardous equipment whenever possible. Use electric tools
or tools with engines that are separate from the tool and can
be located outside and away from air intakes.
- Learn to
recognize the warning symptoms of CO poisoning.
- If you
have any symptoms, immediately turn off equipment and go outdoors
or to a place with uncontaminated air.
- Call 911
or another local emergency number for medical attention or assistance
if symptoms occur. Do NOT drive a motor vehicle--get someone else
to drive you to a health care facility.
- Stay away
from the work area until the tool has been deactivated and measured
CO concentrations are below accepted guidelines and standards.
- Watch coworkers
for the signs of CO toxicity.
Tool
Rental Agencies Should:
- Put warning
labels on gasoline-powered tools. For example:
WARNING--CARBON MONOXIDE PRODUCED DURING USE CAN KILL--DO NOT
USE INDOORS OR IN OTHER SHELTERED AREAS.
- Tell renters
that gasoline-powered tools should NOT be used indoors and explain
why.
- Recommend
safer tools for the intended use if available.
- Have portable,
audible CO monitors for rent and encourage their use.
- Provide
renters with educational materials like this information sheet.
Tool
Manufacturers Should:
- Design tools
that can be used safely indoors.
- Provide
warning labels for existing and new gasoline-powered equipment.
For example:
WARNING--CARBON MONOXIDE PRODUCED DURING USE CAN KILL--DO
NOT USE INDOORS OR IN OTHER SHELTERED AREAS.
- Provide
recommendations for equipment maintenance to reduce CO emissions.
- Recommend
the use of portable, audible CO monitors with small gasoline-powered
engines.
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