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Biosafety Manual
Hazardous Chemical Precautions
Code:
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1. Hazardous Chemical Precautions
2. Objectives and scope
Workers in TB laboratories are not only exposed to pathogenic microorganism, but also
to chemical hazards. It is important that they have proper knowledge of the toxic effects
of these chemicals, the routes of exposure and the hazards that may be associated with
handling and storage.
This SOP describes the chemical hazards that are found in the laboratory and the
precautions to be taken in handling them. Additionally it describes how important it is to
have proper knowledge of the toxic effects of these chemicals.
This SOP is applicable to all employees of the laboratory.
3. Abbreviations, definitions and terms
•
•
SOP
TB
Standard Operating Procedure
Tuberculosis
Hazardous material: a substance or material, which has been determined to be capable
of posing an unreasonable risk to health, safety and property when being used or
handled. In this SOP, we shall refer to laboratory chemicals.
4. Tasks, responsibilities and accountabilities
Task
Ensuring MSDSs are
available for all chemicals
Responsible
Bio safety officer
Accountable
Lab manager
5. Safety and environment
N.A.
6. Procedure
Material safety data sheets (MSDS) or other chemical hazard information MUST be
accessible in the laboratory section where chemicals are used.
6.1 Routes of exposure to dangerous chemicals
a. Inhalation
b. Contact
c. Ingestion
d. Needle-sticks
e. Through broken skin.
6.2 Storage of chemicals
Only amounts of chemicals necessary for daily use should be stored in the laboratory.
Bulk stocks should be kept in specially designated rooms or buildings.
Chemicals should not be stored in alphabetical order but in order of hazard
characteristics.
6.3 General rules regarding chemical incompatibilities
Source: GLI Stepwise Process towards TB Laboratory Accreditation
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Biosafety Manual
Hazardous Chemical Precautions
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To avoid fire and/or explosions, substances in the left-hand column of Table 1, should be
stored and handled so that they cannot come into contact with the corresponding
substances in the right-hand column of the table.
a. Toxic effects of chemicals
Some chemicals adversely affect the health of those who handle them or inhale their
vapours. Apart from overt poisons, a number of chemicals are known to have various
toxic effects. The respiratory system, blood, lungs, liver, kidneys and the gastrointestinal
system, as well as other organs and tissues may be adversely affected or seriously
damaged. Some chemicals are known to be carcinogenic or teratogenic. Some solvent
vapours are toxic when inhaled.
Apart from the more serious effects noted above, exposure may result in impairments
that show no immediate discernible effects on health, but can include lack of
coordination, drowsiness and similar symptoms, leading to an increased proneness to
accidents.
Prolonged or repeated exposure to the liquid phase of many organic solvents can result
in skin damage. This may be due to a deflating effect, but allergic and corrosive
symptoms may also arise.
Table 1. General rules for chemical incompatibilities
b. Explosive chemicals
1. Azides, often used in antibacterial solutions, should not be allowed to come
into contact with copper or lead (e.g. in waste pipes and plumbing), as they
may explode violently when subjected even to a mild impact.
2. Ethers that have aged and dried to crystals are extremely unstable and
potentially explosive.
3. Perchloric acid, if allowed to dry on woodwork, brickwork or fabric, will
explode and cause a fire on impact.
4. Picric acid and picrates are detonated by heat and impact.
c. Chemical spills
Most manufacturers of laboratory chemicals issue charts describing methods for dealing
with spills. Appropriate charts shall be displayed in a prominent position in the
laboratory. The following equipment shall also be provided:
1. Chemical spill kits
2. Protective clothing, e.g. heavy-duty rubber gloves, overshoes or rubber boots,
respirators
3. Scoops and dustpans
4. Forceps for picking up broken glass
5. Mops, cloths and paper towels
6. Buckets
7. Soda ash (sodium carbonate, Na2CO3) or sodium bicarbonate (NaHCO3) for
neutralizing acids and corrosive chemicals
8. Sand (to cover alkali spills)
9. Non-flammable detergent.
Source: GLI Stepwise Process towards TB Laboratory Accreditation
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Biosafety Manual
Hazardous Chemical Precautions
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The following actions should be taken in the event of a significant chemical spill.
1. Notify the appropriate safety officer.
2. Evacuate non-essential personnel from the area.
3. Attend to persons who may have been exposed or contaminated.
4. If the spilled material is flammable, extinguish all open flames, turn off gas in
the room and adjacent areas, open windows (if possible), and switch off
electrical equipment that may spark.
5. Avoid breathing vapor from spilled material.
6. Establish exhaust ventilation if it is safe to do so.
7. Secure the necessary items (see above) to clean up the spill.
6.4 Precautions to be taken while working with chemicals at laboratory
1. Never grasp bottles of acid, caustic materials or any other agents by the neck.
Instead, hold them firmly around the body with both hands with some fingers
holding the bottom.
2. Bottle-carriers should be used to carry acids or caustic material if these
materials are not in plastic coated glass bottles.
3. Use the laboratory fume hood to confine and exhaust odorous, corrosive, and
toxic fumes generated in the laboratories.
4. Wear protective eyeglasses or goggles when working with acids and caustic,
explosive, and molten materials. Contact lenses are not considered protective
glasses.
5. When diluting acids, always add acid slowly to water while mixing. Water
must never be added to concentrated acids. It will rapidly generate heat
that can break the container and cause splattering which may burn skin and
eyes.
6. When making acid or alkaline reagents in large quantities perform all mixing
in a sink. The sink provides water for cooling and confines the reagents in the
event of glass breakage.
7. When pouring chemicals or reagents into a drain, use large amounts of water
to flush the reagent. Do not pour two or more different reagents one after
another. Flush a large quantity of water between them, particularly when
pouring acid reagents followed by cyanide salts, which generates the toxic
fume HCN.
8. Never pour any petroleum solvents into a sink. Waste liquid should be
collected into a safety can and properly disposed of by a company specialized
in this.
9. Dispense strong acids, caustic materials, and strong oxidizing reagents by
automatic pipetting devices, never by mouth.
10. Label all reagents and other chemical materials properly with their contents,
date of preparation, date of expiration when appropriate, and the initials of
the person preparing the reagent. If the reagent is toxic, carcinogenic, etc., it
should be clearly marked on the label.
11. Store all flammable solvents in a steel safety cabinet marked "Flammable
Substances" and keep open flames away from the cabinet.
12. Store and use all flammable and combustible liquids in approved containers.
The aggregate capacity outside the storage cabinets in any one-laboratory
unit should not exceed 10 gallons. All quantities of liquids in excess of 10gallons/laboratory area should be stored in a flammable storage cabinet that
may not contain more than 60 gallons.
13. Keep all sources of sparks and hot plates away from flammable solvents.
14. Eyewash stations are located in or near each laboratory.
15. Carcinogenic, or suspected carcinogenic chemicals and materials if used, in
addition to being explicitly labeled as such, should be used under a safety
hood.
16. Except for purchased chemicals, laboratories are exempt from labeling
requirements.
Source: GLI Stepwise Process towards TB Laboratory Accreditation
Institution
Laboratory name
Location
Head/Responsible person
Biosafety Manual
Hazardous Chemical Precautions
Code:
Version: no.
Date: of release
Page: 4 of 4
6.5 Emergency safety procedures with specific chemicals
The most common dangers from chemicals are burns, explosions, fires, and toxic
fumes. Splattering from acid, caustic material and strong oxidizing agents
represents the greatest hazard to clothing, eyes, and skin. The following consists of
precautions that protect personnel.
i.
Acid or Alkali Burns:
Immediately flush with large quantities of water using sink, emergency shower,
or eyewash station for a full five minutes.
ii. Acid Spill:
Cover with sodium bicarbonate powder or Spill Control Pillows. Allow to
neutralize and clean up if spill is small.
iii. Mercury Spillage:
Isolate the spill area to prevent spreading
7. Related documents
Quality Manual
SOP ‘Responsibilities of the Biosafety officer and biosafety committee’
8. Related forms
SOP ‘Incident Report’, appendix 1
9. References
Safety in health-care laboratories. Geneva, World Health Organization, 1997, (http://
whqlibdoc.who.int/hq/1997/WHO_LAB_97.1.pdf).
Furr AK. CRC handbook of laboratory safety, 5th ed. Boca Raton, FL, CRC Press, 2000.
Lenga RE. The Sigma-Aldrich Library of Chemical Safety Data, 2nd ed. Milwaukee, WI,
Aldrich Chemical Company, 1988.
Lewis RJ. Sax’s dangerous properties of industrial materials, 10th ed. Toronto, John
Wiley
and Sons, 1999.
Biosafety in Microbiological and Biomedical Laboratories. J.H. Richardson and W.E.
Barkley, eds. U.S. Dept. of Health and Human Services, Washington, D.C., 1984.
10. Attachments / Annexes
N.A.
Source: GLI Stepwise Process towards TB Laboratory Accreditation