Manual
Collected & Prepared By
Nasser Udein S. Abu shaaban
Yussuf M. Abd Elal
Medical Technology Department
Islamic University-Gaza
2014
1
2
Lab : 1
Safety in clinical lab
People working in medical laboratory are exposed to potential hazards, risks can be
minimized by eliminating dangerous situation when possible, establishing clean and
safe work habits, taking proper precautions at all times, and maintaining awareness of
good safety practices. The main possible dangers in laboratory are:
1.
Infection
2.
Fire
3.
Contact with corrosive chemicals
4.
Toxic fumes
5.
Carcinogens
6.
Cuts or punctures from broken glassware or other sharp objects.


Infection:
Laboratory personnel and analyzed blood and body fluids that may contain
infective agents from sick and seemingly well patients.
The greatest danger of disease transmission arises from:
 An accidental puncture from a contaminated needle {blood born disease}
Exposures of cuts or skin punctures to infective fluids that are spilled or
allowed to contaminated the outer surface of their container.
 Aerosols that escape when opening a vacutainer or after centrifugation, or
from bacterial culture.
Transmission by the oral rout for some parasitic types.
Transmission of disease can be minimized by practicing the universal precautions:
1.
Access to the laboratory is controlled, free access or through traffic is not
allowed. The lab. door should remain closed and a sign should be
prominently displayed on the door, indicating that the room is a clinical lab
where a variety of infectious agents or chemicals may be present at any
time.
The lab director should be the individual responsible for limiting access to the
lab; in general people with immunological deficiencies, pregnancy, children
under the age of 16, and animals not involved in lab procedures, should never
be allowed in the lab.
3
2.
Work surfaces should be decontaminated at least once a day and
immediately following any spill involving potentially infectious material. In
most cases, surfaces can be decontaminated with alcohol 70% or any other
effective disinfectant such as:
Alcohol 70% is lethal for all vegetative cells, as it disrupts cellular
membranes.
 Phenolic compounds 10%, such as phenol (carbolic acid), Lysol, Tylenol
(Dettol) used for floors and surfaces.
Halogens such Iodine and chlorine act as oxidizing agents. Such as
hypochlorite (0.5%)
Detergents.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Mouth pipetting should never be permitted; there are mechanical pipetting
devices for every lab, and situations.
Eating, drinking, and smoking should be strictly prohibited, food may be
stored in cabinets or refrigerators located outside the work area, these
cabinets or refrigerators should not be used for storage any microbiological
or chemical reagents and supplies.
Special care should always be taken to avoid contact between skin or
mucous membranes and potentially infectious materials. This usually
means wearing gloves (disposable once) for all lab work including drawing
blood.
Lab coats should be worn in the lab and removed before leaving.
Any skin surface that becomes contaminated should be washed
immediately; hands must be washed upon removal of gloves.
All needles should not be recapped, bent, or broken but should be placed in
sharp container for disposable.
All specimens for centrifugation must be done in closed tubes.
Dispose of samples properly when no longer needed for possible
reanalyzed. Samples should be autoclaved before discarding.
Avoid any aerosol or droplets when opening a vacuum tube containing
blood. (Point tube away from yourself and open slowly).
Use pipettes or other devices for transferring fluid samples. Don’t pour
from one tube to another because a drop or two may contaminate the outer
surface of the tube.
Treat all lab specimens as infectious, make no exceptions and don’t rely on
warning labels to designate contaminated specimens.
4

Fire:
The danger of fire is always present as long as volatile flammable solvents are in
the lab, a static spark can set off an explosion if the proper mixture of the
flammable substance with air is present.
The following precautions are advised:
1. When possible, substitute solvents with higher boiling point for the more
dangerous solvents with lower boiling point. The following solvent listed is
ascending order of their B.P:
1. Ethyl Ether 34 o C
6. Petroleum ether 40-60 oC
2. Acetone 56 oC
7. Methanol 65 oC
3. Ethyl acetate 77 oC
8. Ethanol 78.5 o C
4. Isopropanol 96 o C
9. Toluene 111 oC
5. Xylene 139 oC
2.
3.
4.
5.
6.
7.
8.
Always work in a fume hood with the blower on, when using flammable
solvents.
Keep the laboratory supply of flammable solvents to a minimum and store
them in a flameproof cabinet.
Don’t permit smoking in the lab.
When flame is necessary, use a mechanical igniter instead of matches to
light the flame.
Place Co2 fire extinguishers at strategic locations in the lab and have drills
to make certain that all personal know where they are located and how to
use them.
All connections of flammable gases to instruments, such as flame
photometer must leak proof after making a new connection, check for leaks
by painting the threads with soap solution and looking for bubbles.
Never store flammable solvents in a refrigerator or freezer in which the
thermostat is inside the compartment; a spark may explode the vapor
mixture with tremendous force. Lab refrigerators and freezers should be
converted so those thermostats are outside the cold compartment.


5

Corrosive chemicals:
Strong acids and alkalis are the most common corrosive chemicals to which
clinical technologist are exposed.
Most accidents occur through the splashing of reagents during their preparation.
Hazards from chemicals by direct effect when contact with skin, eyes, lips …etc.
The following precautions are advised:
1.
2.
3.
4.
5.
6.
7.
Protective goggles when preparing corrosive chemicals.
Corrosive chemicals must be properly labeled.
All bottles containing reagents should be in low shelves to avoid accidents.
In dilution don’t pour water onto acids.
Avoid mouth pipetting.
Don’t heat the bottom, but the middle of the test tubes.
Don’t heat ordinary glass, but Pyrex.



Toxic fumes:
In some sections of a laboratory, one must occasionally prepare extracts with
volatile solvents whose vapor is toxic, this toxicity is particularly true of
chlorinated hydrocarbons (CH2Cl 2 , CH3 Cl, CHCl3 CCl4 ) or benzene used as solvents.
Continued exposure to these agents may cause liver damage; some may depress
bone marrow activity or affect other organ systems.
The following precautions are advised:
1.
2.
3.
Always work in a fume hood with good ventilation whenever evaporating
or using organic solvents.
Avoi d contamination of the skin with solvents because they are slowly
absorbed. If solvent gets on the skin, wash it with soap and water.
Make sure that the lab is well ventilated, because exposure to low
concentration of vapor for a long time is also dangerous.




Carcinogens:
After chemicals used in the lab, particularly aromatic amines, may be carcinogens.
6
The following precautions are advised:
1.
Substitute a non-carcinogenic compound for a known carcinogenic when
possible, for example: Benzidine is a carcinogen that can be replaced by
tetramethyl benzidine which posses little danger.
When substitution is not possible then: a) avoid spilling of reagents or
creating dust when weighing or transferring chemicals. b) Wear rubber
gloves and facemask when necessary. c) Clean the work area when
finished, and wash hands thoroughly with soap and water.
2.




Broken glassware:
Any flasks or beakers with broken lips are a source of danger; they should be
destroyed and replaced.
7