Environmental Engineering Reference
In-Depth Information
3. Use safe work practices:
•
De-energize electric equipment before inspecting or making
repairs.
•
Use electrical tools that are in good repair.
•
Use good judgment when working near energized lines.
•
Use appropriate protective equipment.
1.13.8 fire safety (29 Cfr 1910.38, 1910.106, and 1910.157)
Wastewater treatment plants are not immune to fire and its ter-
rible consequences. Fortunately, plant safety officials are aided in their
fire prevention and control efforts by the authoritative and professional
guidance available from the National Fire Protection Association (NFPA),
the National Safety Council (NSC), fire code agencies, local fire authori-
ties, and OSHA regulations.
Along with providing fire prevention guidance, OSHA regulates
several aspects of fire prevention and emergency response. Emergency
response, evacuation, and fire prevention plans are required under
29 CFR 1910.38. Additionally the requirement for fire extinguishers and
worker training are addressed in 29 CFR 1910.157. More specifically,
OSHA, along with state and municipal authorities, has listed several
fire safety requirements for general industry.
All of these advisory and regulatory authorities approach fire safety
in much the same manner. For example, they all agree that fires in the
workplace are usually started by electrical short circuits or malfunc-
tions. Along with electrical causes, other leading causes of fire in the
workplace are friction heat, welding and cutting of metals, improperly
handled chemicals, improperly stored flammable/combustible materi-
als, open flames, and cigarette smoking.
For fire to start, three ingredients are needed:
Heat + Fuel + Oxygen
It is the objective of fire prevention and firefighting to separate any one
of these ingredients from the other two. For example, to prevent fires,
keep fuel (i.e., combustible materials) away from heat; store such mate-
rials in airtight containers to isolate the fuel from the oxygen in the air
and heat.
To help in gaining a better perspective of the chemical reaction
known as fire it should be pointed out that the combustion reaction
normally occurs in the gas phase, and, generally, the oxidizer is air. If a
flammable gas is mixed with air, there is a minimum gas concentration
below which ignition will not occur. That concentration is known as the
lower flammable limit (LFL). When considering the LFL and its coun-
terpart, the upper flammable limit (UFL), it helps to refer to the famil-
iar example of the combustion process that occurs in the automobile
