NCF EXAM WITH COMPLETE SOLUTIONS 100%
VERIFIED LATEST UPDATE
1. The most serious hazard for all laboratory workers is fire. It is necessary that each
worker knows the location of the fire extinguishers and fire alarm pull stations. It is also
very important to know the types of fires for which different commercial extinguishers
are designed. There are four general classes of fires. List each of the classes of fires
and the type of extinguisher which you should use to put out the fire. - ANSWER Class A
Fires: Ordinary combustible solids: paper, rubber, textiles. Frequently accompanied by
destructive distillation producing flaming vapors or toxic gases. These fires may also
leave hot ash or residue capable of re-igniting fire after it looks like it has been put out.
These fires are effectively put out by water which is recommended if the water would
not create additional hazard. These fires are also extinguished by CO2, N2, volatile
halocarbons (CF3Br, etc.) and dry chemical extinguishers, though these may lead to
spreading the burning material due to the blast of compressed gas from the
extinguisher cylinder. Dry ice will generally quickly starve these fires and can be utilized
if it is readily available. Class B Fires: Flammable liquids
One major complication occurring with the spread of the fire is if the container of
burning liquid is knocked over or broken. This kind of fire is put out by placing
something over the container of burning liquid or by the application of foam, C02, N2,
volatile halocarbons or sometimes dry chemical (depending on the situation) from a fire
extinguisher. Again, dry ice or liquid N2 is very effective if it is close by. Compressed
gas extinguishers can cause re-spreading and intensification of the fire in cases where
force from the extinguisher knocks over a container holding the burning liquid. Class C
Fires: These are Type A or B fires at which electrical equipment is involved.
These fires can be treated as class A or B if power is turned off. It is a good practice to
never use water on a fire when electrical equipment is present, even in the event power
is disabled (some electrical equipment will store charge). If the power cannot be turned
off the fire must be extinguished with inert gas or dry chemicals. Again, dry ice or liquid
N2 is very effective if available. Class D Fires: These fi 2. Chemical hazards also exist in
the laboratory and it's very important to know what hazards you may encounter in a lab.
If you are working with a chemical and you do not know the hazards associated with it
you need to ask your supervisor or consult the references listed in the beginning of the
quiz. Name some common hazards associated with chemicals. - ANSWER Common
chemical hazards include:
, Fire Hazards,
Explosions Hazards from incompatible chemicals ,
Extremely Toxic Chemicals, Lachrymators-substances that irritate the eyes and
produce tears,
Vesicants-substances that can blister and burn body tissues by contact with the skin or
inhalation,
Carcinogens-substances that produce cancer
3. Explain the problems which may be associated with wearing contact lenses in a
chemical laboratory.
- ANSWER If chemicals should enter the eye, these can be held against the eyeball and
not washed free due to contact coverage.
Also, soft contacts will often absorb organic vapors like MeOH, CHCI3 or serious
lachrymators. If you should be unconscious after a laboratory accident, the people
attending you may not know that you wear contacts and may not be able to tell easily if
What is the fire alarm, and what is its purpose? - ANSWER These are just loud buzzers
throughout the building. If you hear the fire alarm, take a quick exit from the building!
They call UIC police and fire department automatically. 5. In case of fire, chemical spill,
or other emergency, appropriate safety equipment should be readily available.
Air packs and respirators should only be used by those personnel trained to use them.
It is preferable to call the fire department where personnel are highly trained in the use
of air packs. What are appropriate circumstances for using fire fighting equipment and
first aid equipment? ANSWER Laboratory staff should only try to extinguish small fires
when they feel confident the fire can be put out quickly and without putting themselves
at risk. Once extinguished, they must contact UIC police and EHSO, reporting the fire
and use of equipment. If the fire is too large to extinguish in a very short period, alert the
fire department if at all possible by using a phone. Pull a fire alarm to alert others to
evacuate the building and guide fire fighters to the location upon their arrival. Provide
first aid to anyone injured. This involves taking the victim away from the source of injury
and stabilization of life-threatening conditions such as bleeding and shock, and also
absence of breathing or heartbeat. 6. If an emergency were to occur that required
urgent evacuations of the lab, some of the labs are interconnected by emergency doors.
These are kept locked to prevent fire from spreading easily and also for security issues.
VERIFIED LATEST UPDATE
1. The most serious hazard for all laboratory workers is fire. It is necessary that each
worker knows the location of the fire extinguishers and fire alarm pull stations. It is also
very important to know the types of fires for which different commercial extinguishers
are designed. There are four general classes of fires. List each of the classes of fires
and the type of extinguisher which you should use to put out the fire. - ANSWER Class A
Fires: Ordinary combustible solids: paper, rubber, textiles. Frequently accompanied by
destructive distillation producing flaming vapors or toxic gases. These fires may also
leave hot ash or residue capable of re-igniting fire after it looks like it has been put out.
These fires are effectively put out by water which is recommended if the water would
not create additional hazard. These fires are also extinguished by CO2, N2, volatile
halocarbons (CF3Br, etc.) and dry chemical extinguishers, though these may lead to
spreading the burning material due to the blast of compressed gas from the
extinguisher cylinder. Dry ice will generally quickly starve these fires and can be utilized
if it is readily available. Class B Fires: Flammable liquids
One major complication occurring with the spread of the fire is if the container of
burning liquid is knocked over or broken. This kind of fire is put out by placing
something over the container of burning liquid or by the application of foam, C02, N2,
volatile halocarbons or sometimes dry chemical (depending on the situation) from a fire
extinguisher. Again, dry ice or liquid N2 is very effective if it is close by. Compressed
gas extinguishers can cause re-spreading and intensification of the fire in cases where
force from the extinguisher knocks over a container holding the burning liquid. Class C
Fires: These are Type A or B fires at which electrical equipment is involved.
These fires can be treated as class A or B if power is turned off. It is a good practice to
never use water on a fire when electrical equipment is present, even in the event power
is disabled (some electrical equipment will store charge). If the power cannot be turned
off the fire must be extinguished with inert gas or dry chemicals. Again, dry ice or liquid
N2 is very effective if available. Class D Fires: These fi 2. Chemical hazards also exist in
the laboratory and it's very important to know what hazards you may encounter in a lab.
If you are working with a chemical and you do not know the hazards associated with it
you need to ask your supervisor or consult the references listed in the beginning of the
quiz. Name some common hazards associated with chemicals. - ANSWER Common
chemical hazards include:
, Fire Hazards,
Explosions Hazards from incompatible chemicals ,
Extremely Toxic Chemicals, Lachrymators-substances that irritate the eyes and
produce tears,
Vesicants-substances that can blister and burn body tissues by contact with the skin or
inhalation,
Carcinogens-substances that produce cancer
3. Explain the problems which may be associated with wearing contact lenses in a
chemical laboratory.
- ANSWER If chemicals should enter the eye, these can be held against the eyeball and
not washed free due to contact coverage.
Also, soft contacts will often absorb organic vapors like MeOH, CHCI3 or serious
lachrymators. If you should be unconscious after a laboratory accident, the people
attending you may not know that you wear contacts and may not be able to tell easily if
What is the fire alarm, and what is its purpose? - ANSWER These are just loud buzzers
throughout the building. If you hear the fire alarm, take a quick exit from the building!
They call UIC police and fire department automatically. 5. In case of fire, chemical spill,
or other emergency, appropriate safety equipment should be readily available.
Air packs and respirators should only be used by those personnel trained to use them.
It is preferable to call the fire department where personnel are highly trained in the use
of air packs. What are appropriate circumstances for using fire fighting equipment and
first aid equipment? ANSWER Laboratory staff should only try to extinguish small fires
when they feel confident the fire can be put out quickly and without putting themselves
at risk. Once extinguished, they must contact UIC police and EHSO, reporting the fire
and use of equipment. If the fire is too large to extinguish in a very short period, alert the
fire department if at all possible by using a phone. Pull a fire alarm to alert others to
evacuate the building and guide fire fighters to the location upon their arrival. Provide
first aid to anyone injured. This involves taking the victim away from the source of injury
and stabilization of life-threatening conditions such as bleeding and shock, and also
absence of breathing or heartbeat. 6. If an emergency were to occur that required
urgent evacuations of the lab, some of the labs are interconnected by emergency doors.
These are kept locked to prevent fire from spreading easily and also for security issues.
