Working in a laboratory usually involves working with various chemical, physical, and biological hazards. Because the hazards vary from laboratory to laboratory, employers must address the hazards specific to their laboratories. Standard precautions are meant to reduce the risk of transmission of blood borne and other pathogens from both recognized and unrecognized sources. They are the basic level of infection control precautions which are to be used, as a minimum, in the health care settings.

1. LABORATORY
SAFETY MEASURES
By
Dr. S. PUGALENDHI, Emeritus Professor
Dr. P. VIJAYAKUMARY, Assistant Professor
Er. T. AYISHA NAZIBA, II-M.Tech.(REE)

2. INTRODUCTION
• Working in a laboratory usually involves working with various chemical, physical,
and biological hazards. Because the hazards vary from laboratory to laboratory,
employers must address the hazards specific to their laboratories.
• Standard precautions are meant to reduce the risk of transmission of blood borne
and other pathogens from both recognized and unrecognized sources.
• They are the basic level of infection control precautions which are to be used, as a
minimum, in the health care settings.

3. PREPARING FOR LAB WORK
Before starting to work in a laboratory, you must familiarize with the following:
• The hazards of the materials in the lab, as well as appropriate safe handling, storage
and emergency protocols.
• Read labels and material safety data sheets (MSDSs) before moving, handling or
opening chemicals. Never use a product from an unlabeled container, and report
missing labels to your supervisor.
• The agents, processes and equipment in the laboratory. If you are unsure of any
aspect of a procedure, check with your supervisor before proceeding.
• The location and operation of safety and emergency equipment such as fire
extinguishers, eye wash and shower, first aid and spill response kits, fire alarm pull
stations, telephone and emergency exits
• Emergency spill response procedures for the materials you will handle

4. OSHA LABORATORY SAFETY
STANDARD
• The OSHA (Occupational Safety and Health Administration) Laboratory Safety
Standard, 29 CFR (Code of Federal Regulations) Part 1910.1450, addresses the issue
of local responsibility by requiring that each laboratory develop an individual
chemical hygiene plan as part of an overall organizational plan.
• The standard applies only to laboratory use of chemicals and their hazards. The
definition of hazard is very broad - “a hazardous chemical means one for which
there is statistically significant evidence based on at least one study conducted in
accordance with established scientific principles that acute or chronic health effects
may occur in exposed employees.

5. • The term ‘health hazard" includes chemicals which are carcinogens, toxic or highly
toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatoxins,
nephrotoxins, agents which act on the hematopoietic systems, and agents which
damage the lungs, skin, eyes or mucous membranes.”
• The standard also mentions physical hazards for materials that are flammable,
combustible, compressed gases, explosives, oxidizers, organic peroxides,
pyrophoric, reactive or unstable, or water reactive.
• Not all uses of chemicals with these properties are covered by the standard but only
those uses which occur in a “laboratory” on a “laboratory scale.”

6. LABELING
Labels
labels on commercial containers
The are usually extremely comprehensive,
providing not only information on the nature,
amount, and quality of the product but also a very
large amount of safety-related data. Typically a
commercial label will readily meet the
requirements of the hazard communication
standard.
labels placed on secondary containers
something such as “soln. A” or even less. This may
be sufficient if all of the material is to be promptly
used by the individual placing the label on the
container, but otherwise it is not. In most
instances, secondary containers of hazardous
chemicals should be marked with labels
identifying the chemical in the container and
providing basic hazard warnings. The secondary
label should be affixed before the container is put
into use.

8. HOUSEKEEPING
• Housekeeping also means maintaining the laboratory in a reasonably organized
fashion on a day-to-day basis. This is the responsibility of all laboratory
personnel, but individuals will follow the laboratory manager's own performance
as a guide.
• Clean and maintain the floor area.
• Dispose of ordinary trash. However, if other than ordinary solid waste is generated
in the laboratory; it should be placed in distinctively shaped and/or colored
containers. If the custodians are still expected to handle it, then the circumstances
and procedures should be carefully delineated and training given. This latter
responsibility is not recommended.
• Wash windows. If they are expected to wash bench tops or other laboratory
furniture, it should be only when additional supervision is provided by laboratory
personnel.

9. SIGNS AND SYMBOLS

11. CORROSIVE CHEMICALS
• The definition of corrosive chemicals is very broad. However, in the sense that the
action of the chemical will result in an immediate, acute erosive effect on tissue as
well as other materials, strong acids and bases, dehydrating agents, and
oxidizing agents are commonly considered to be corrosive materials.
• These terms may not be mutually exclusive. Accidents with corrosive materials in
which the material may splash on the body are very common in the
laboratory .
• The eyes are particularly vulnerable to injury, and injuries to the respiratory
system may range from moderate irritation to severe injury.
• Skin injuries may be very slow to heal. Ingestion can cause immediate injury to the
mouth, throat, and stomach, and in severe cases can lead to death.

12. 1. STRONG ACIDS
• Concentrated strong acids can cause severe and painful burns.
• The pain is due in part to the formation of a protein layer which resists further
penetration of the acid.
• In general, inorganic acids are more dangerous than organic acids, although
the latter can cause deep-seated burns on extended contact with the skin.
• Leakage from containers and material remaining on the outside of the
containers following a sloppy transfer can cause corrosion of the shelving and, if
the acids are stored with materials with which they may react, accidents can result if
the chemicals come into contact.

13. 2. STRONG ALKALIS
• Alkali metal hydroxides are very dangerous when allowed to come into contact
with tissue.
• The contact with the skin is likely to be less painful than a comparable exposure to
acid because a protective protein barrier is not formed.
• Damage may extend to greater depths as a result of the lesser pain because the
injured person may not be as aware of the seriousness of the incident.
• Any area exposed to a strong alkaline material should be flooded with water for at
least 15 minutes or longer.
• This is especially important in eyes since the result of an exposure can be a rupture
of the global structure of the eye.

14. 3. NONMETAL CHLORIDES
• Compounds such as phosphorous trichloride and corresponding bromides react
violently with water and are a common cause of laboratory accidents.

15. 4. DEHYDRATING AGENTS
• Strong dehydrating agents such as sulfuric acid, sodium hydroxide, phosphorous
pentoxide, calcium oxide, and glacial acetic acid can cause severe burns to
the eyes because of their strong affinity to water.
• When they are added to water too rapidly, violent reactions accompanied by
spattering can occur.

16. 5. HALOGENS
• Halogens are corrosive on contact with the skin, eyes, and the linings of the
respiratory system as well as being toxic.
• Because they are gases, they pose a greater danger, especially by inhalation, of
coming into contact with sensitive tissue.

17. GLASSWARE CLEANING
• Cleaning of glassware in laboratories is an essential part of laboratory procedures.
• In most cases a simple cleaning with soap and water is sufficient, but in some cases
chemical cleaning is necessary.
• Strong chemical agents such as sulfuric acid, perchloric acid, chromic acid, nitric
acid, etc. should not be used unless the need specifically exists.
• When employing these strong reagents, protective gloves, eye protection,
chemically resistant aprons, and possibly respiratory protection are recommended.