Preventing Carbon Monoxide Poisoning
from Small Gasoline-Powered
Engines and Tools
WARNING!
Indoor use of gasoline-powered engines and tools is risky business.
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.
RECOMMENDATIONS
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.
FOR MORE INFORMATION
For additional information, see the complete publication entitled
ALERT: Preventing Carbon Monoxide Poisoning from Small Gasoline-Powered
Engines and Tools [DHHS (NIOSH) Publication No. 96-118].
Single copies of the Alert are available free from the following:
Publications Dissemination, EID
National Institute for Occupational Safety and Health
4676 Columbia Parkway
Cincinnati, OH 45226