This document provides information on preventive and protective management for fire and explosion in the pharmaceutical industry. It discusses various methods for management including electricity passivation through bonding and grounding, ventilation through local exhaust and dilution, sprinkling systems, and explosion proofing of electrical devices. Relief systems for fire and explosion such as relief valves, flares, and scrubbers are also outlined. The document provides detailed descriptions and examples for each method. It was presented by Manikandan V for a course on pharmaceutical quality assurance at Annamalai University.

1. Presented by,
Manikandan V,
2061050002,
M. Pharm (Pharmaceutical Quality Assurance),
Department of Pharmacy,
Annamalai University.
Submitted to
Dr. G. Sivakamasundari, M. Pharm., Ph. D.,
Assistant Professor,
Department of Pharmacy,
Annamalai University.
UNIT IV
FIRE AND EXPLOSION
Preventive and Protective Management from Fire
and Explosion, Relief Systems

2. Preventive and Protective Management from
Fire and Explosion
The various methods for management from fire and
explosion are follows;
 Electricity passivation
 Ventilation
 Sprinkling
 proofing

3. Electricity Passivation:
Static electricity
 Sparks due to static charge buildup and sudden discharge.
 Static charge buildup is a result of physically separating a
poor conductor from a good conductor or another poor
conductor.
 Generated when a fluid flows through a pipe or from an
opening into a tank.
 Main hazards are fire and explosion from sparks containing
enough energy to ignite flammable vapors.

4.  Bonding or grounding of flammable liquid containers is
necessary to prevent static electricity from causing a spark.
Bonding
 Physically connect two conductive objects together with a
bond wire to eliminate a difference in static charge potential
between them.
 Must provide a bond wire between containers during
flammable liquid filling operations, unless a metallic path
between them is otherwise present.

5. Grounding
 Eliminates a difference in static charge potential between
conductive objects and ground.
 Although bonding will eliminate a difference in potential
between objects, it will not eliminate a difference in
potential between these objects and earth unless one of the
objects is connected to earth with a ground wire.

6. Ventilation:
 The purpose of ventilation is to dilute the explosive vapors
with air to prevent explosion and to confine the hazardous
flammable mixtures.
 Always provide adequate ventilation to reduce the potential
for ignition of flammable vapours.
Open Air Plants
 Average wind velocities are high enough to safely dilute
volatile chemical leaks which may exist within a plant.

7. Plants Inside Buildings
 Local ventilation - the most effective method for
controlling flammable gas releases.
 Dilution ventilation - also used because the potential
points of release are usually numerous and it may be
mechanically or economically impossible to cover every
potential release point with only local ventilation.

8. Local Exhaust Ventilation
 Local exhaust ventilation systems remove the contaminant
before it spreads through the workplace.
 They are most useful for controlling toxic materials when
their airborne concentrations could exceed legislated
standards.

9. Dilution/General Ventilation
 General (dilution) ventilation systems supply clean air that
mixes with the air in the workplace, diluting the
concentration of the contaminant.
 It is not suitable to control exposure to toxic substances
because these systems actually spread the contaminant
throughout the workplace before exhausting it.

10. Sprinkling:
 The system consists of an array of sprinkler heads
connected to a water supply. The heads are mounted in a
high location (usually near ceilings) and disperse a fine
spray of water over an area when activated.
 The control point is connected to an array of heat and/or
smoke detectors that start the sprinklers when an abnormal
condition is detected. If a fire is detected, the entire
sprinkler array within an area is activated, possibly in
areas not even affected by the fire.

11. Proofing:
 All electrical devices are inherent ignition sources. Most
safety practices for electrical installations are based on the
National Electric Code (NEC).
 Process areas are divided into two major types of
environments/area:
 Explosion Proof (XP) - flammable materials
(particularly vapors) might be present at certain times.
 Non-explosion Proof (non-XP) - flammable materials
are not present even under abnormal conditions.

12. Explosion Proof
 In an XP area, the electrical equipment and some
instrumentation must have special explosion proof
housings.
 The housings are not designed to prevent flammable
vapors and gases from entering but are designed to
withstand an internal explosion and prevent the
combustion from spreading beyond the inside of the
enclosure.

13. Relief Systems
The relief system for fire and explosion follows;
 Relief valves
 Flares
 Scrubbers

14. Relief Valves:
 A relief valve or pressure relief valve (PRV) is a type of
safety valve used to control or limit the pressure in a
system; pressure might otherwise build up and create a
process upset, instrument or equipment failure, or fire.
 The pressure is relieved by allowing the pressurized fluid to
flow from an auxiliary passage out of the system.
 The relief valve is designed or set to open at a
predetermined set pressure to protect pressure vessels and
other equipment from being subjected to pressures that
exceed their design limits.

15.  When the set pressure is exceeded, the relief valve
becomes the "path of least resistance" as the valve is
forced open and a portion of the fluid is diverted through
the auxiliary route.
 In systems containing flammable fluids, the diverted fluid
(liquid, gas or liquid-gas mixture) is usually routed
through a piping system known as a flare header or relief
header to a central, elevated gas flare where it is usually
burned and the resulting combustion gases are released to
the atmosphere.

16.  In non-hazardous systems, the fluid is often discharged to
the atmosphere by a suitable discharge pipework designed
to prevent rainwater ingress which can affect the set lift
pressure, and positioned not to cause a hazard to personnel.
 As the fluid is diverted, the pressure inside the vessel will
stop rising. Once it reaches the valve's reseating pressure,
the valve will close. The blowdown is usually stated as a
percentage of set pressure and refers to how much the
pressure needs to drop before the valve reseats.
 The blowdown can vary from roughly 2–20%, and some
valves have adjustable blowdowns.

17. Flares:
 A flare, also sometimes called a fuse, is a type of pyrotechnic
that produces a bright light or intense heat without an
explosion. Flares are used for distress signaling,
illumination, or defensive countermeasures in civilian and
military applications. Flares may be ground pyrotechnics,
projectile pyrotechnics, or parachute-suspended to provide
maximum illumination time over a large area. Projectile
pyrotechnics may be dropped from aircraft, fired from rocket
or artillery, or deployed by flare guns or handheld percussive
tubes.

18.  Flares produce their light through the combustion of a
pyrotechnic composition.
 The ingredients are varied, but often based on strontium
nitrate, potassium nitrate, or potassium perchlorate and
mixed with a fuel such as charcoal, sulfur, sawdust,
aluminium, magnesium, or a suitable polymeric resin.
 Flares may be colored by the inclusion of pyrotechnic
colorants. Calcium flares are used underwater to illuminate
submerged objects.

19. Scrubbers:
 Scrubber systems (e.g. chemical scrubbers, gas scrubbers)
are a diverse group of air pollution control devices that can
be used to remove some particulates and/or gases from
industrial exhaust streams. The first air scrubber was
designed to remove carbon dioxide from the air of an early
submarine, the Ictinus, a role for which they continue to be
used today. Traditionally, the term "scrubber" has referred
to pollution control devices that use liquid to wash
unwanted pollutants from a gas stream.

20.  Recently, the term has also been used to describe systems
that inject a dry reagent or slurry into a dirty exhaust
stream to "wash out" acid gases. Scrubbers are one of the
primary devices that control gaseous emissions, especially
acid gases.
 Scrubbers can also be used for heat recovery from hot gases
by flue-gas condensation. They are also used for the high
flows in solar, PV, or LED processes.

21. There are several methods to remove toxic or corrosive
compounds from exhaust gas and neutralize it.
 Combustion
 Dry Scrubbing
 Wet Scrubbing
 Adsorber
 Mercury Removal

22. Combustion
 Combustion is sometimes the cause of harmful exhausts, but,
in many cases, combustion may also be used for exhaust gas
cleaning if the temperature is high enough and enough
oxygen is available.

23. Wet Scrubbing
 The exhaust gases of combustion may contain substances
considered harmful to the environment, and the scrubber
may remove or neutralize those. A wet scrubber is used for
cleaning air, fuel gas or other gases of various pollutants
and dust particles.
 Wet scrubbing works via the contact of target compounds
or particulate matter with the scrubbing solution.
Solutions may simply be water (for dust) or solutions of
reagents that specifically target certain compounds.

24. Dry Scrubbing
 A dry or semi-dry scrubbing system, unlike the wet
scrubber, does not saturate the flue gas stream that is
being treated with moisture. In some cases no moisture is
added, while in others only the amount of moisture that
can be evaporated in the flue gas without condensing is
added. Therefore, dry scrubbers generally do not have a
stack steam plume or wastewater handling/disposal
requirements. Dry scrubbing systems are used to remove
acid gases (such as SO2 and HCl) primarily from
combustion sources.

25. Adsorber
 Many chemicals can be removed from exhaust gas also by
using adsorber material. The flue gas is passed through a
cartridge which is filled with one or several adsorber
materials and has been adapted to the chemical properties
of the components to be removed.
 This type of scrubber is sometimes also called dry
scrubber.
 The adsorber material has to be replaced after its surface
is saturated.

26. Mercury Removal
 Mercury is a highly toxic element commonly found in coal
and municipal waste. Wet scrubbers are only effective for
removal of soluble mercury species, such as oxidized
mercury, Hg2+. Mercury vapor in its elemental form,
Hg0, is insoluble in the scrubber slurry and not removed.
 Usually halogens are added to the flue gas for this
purpose. The type of coal burned as well as the presence
of a selective catalytic reduction unit both affect the ratio
of elemental to oxidized mercury in the flue gas and thus
the degree to which the mercury is removed.

27. References:
 “Fire and Explosion in Pharmaceutical Industry – An
Overview”, Asian Journal of Pharmaceutical and Clinical
Research, Vol. 11, Issue 2, 2019, ISSN – 2455-3891.
 “Relief Systems from fire and Safety Management in
Pharmaceutical Industry – A Review”, Journal of
Pharmacy Research, Vol. 12, Issue 3, 2018, ISSN – 0974-
6943.

28. THANK YOU