Download lab hazards and safety

Laboratory hazards and safety
The Laboratory worker is exposed to many hazards in the medical
Laboratory, so specific precautions must be done to avoid or decrease
the exposure to these hazards.
Source of Laboratory hazards
 Materials
 Samples
 Instruments
Types of Laboratory hazards:
1-Biological hazards:
2-Chemical hazards:
3-fire hazards:
4- Radiation hazards:
5- Toxicity hazards:
6- Mechanical hazards:
7- Electrical hazards:
Biological hazards
There are many hazards in the microbiology lab. By exposure or handling
of the microorganism. These hazards may decrease when lab. workers
are aware of the followings:
1- The potential hazards of the microorganisms.
2- The route of entry of the microorganisms into the body.
3- The correct methods of containing these of these microorganisms.
Routes of infection (ways of entry of the microorganisms into the
body)
By ingestion through mouth during the followings:
1- Mouth pipetting.
2- Contaminated Fingers or articles (Cigarettes, pens)
3- Contaminated food from laboratory bench.
4- Environmental contamination from spills or splashes.
By inhalation through nose to reach lungs:
It occurs by inhalation of infected air-borne particles (aerosols)
Released during many lad manipulation, e.g. infection by T.B. when
Lab workers exposed to aerosol during processing of sputum samples
By injection through skin from the followings
1-Accidental stabbing
2- Microorganisms may entry the body through cut wounds or
absorption of the skin, e.g. Virus infections (HBV,HCV. Or HIV), Tetanus
and wound sepsis (Strept. Or Staph.).
3-Microorganisms may enter through subcutaneous injection by insect
bites like plague and Typhus.
4- Few microorganisms may enter into the body through unbroken skin
like Brucella.
By splashing of infected liquids into the eyes.
Classification of microorganisms on the bases of risk
Microorganisms vary in their ability to cause infections and may be:
Harmless, produce disease with mild symptoms, cause serious disease or
cause serious epidemic diseases.
There are four types on bases of risk:
1-Risk group -1 (low individual and community risk):Microorganisms are
unlikely to cause human disease or animal disease.
2-Risk group-2 (Moderate individual risk and limited community risk):
Pathogens can cause human disease or animal disease without serious
hazards to lab workers or community.
3- Risk group-3 (High individual risk and low community risk): Pathogens
usually can cause serious human disease without spread from infected
individual to another.
4- Risk group -4 ((high individual and community risk)): Pathogens
usually can cause serious human disease with readily transmitted from
infected individual to another. directly or indirectly as epidemic disease.
Methods of production of biological hazards by microorganisms
1- By multiplication of microorganisms when enter the body and
overcome defensive mechanism
2- By production of bacterial toxins from some bacteria
3- By rapid mutation of some bacteria to highly pathogenic which
can resist the antibiotics.
4- Some microorganisms can stimulate an allergic reaction.
5- Culture of non-pathogenic microorganisms may become
contaminated with other pathogenic species like Aspergillus.
It is important to know what Bloodborn pathogen is:
Bloodborn pathogens are microorganisms such as viruses or bacteria
that are carried in blood and can cause disease in people. There are
many different Bloodborn pathogens
including malaria'suphilis'and
brucellosis but hepatitis B (HBV) and the human Immunodeficiency virus
(HIV) are the two diseases specifically addressed by the OSHA ‫منظمة االمن‬
‫ والصحة‬Blood borne pathogen standard
Bloodborne pathogen such as HBV and HIV can be transmitted through
contact with infected human blood and other potentially infectious body
fluids such as:
 Semen ( the viscid fluid from the male)
 Vaginal secretions (the fluid from the female cervix).
 Cerebrospinal fluid (colorless liquid that surrounds the brain and
spinal cord).
 Synovial fluid (fluid that lubricates and cushions the joint)
 Pleural fluid (fluid between the pleural membranes of the lung
and the inner chest wall).
 Peritoneal fluid (fluid in the gastrointestinal organs).
 Amniotic fluid (fluid that surrounds the fetus).
 Saliva (in dental procedures).
 Any body fluid that is visibly contaminated with blood.
"Universal Precautions" is the name used to describe a prevention
strategy in which all blood and potentially infectious materials are
treated as if they are infectious ,regardless of the status of the source
individual, in other words, whether or not you think the blood \body
fluid is infected with Bloodborne pathogens, you treat it as if it is .
NB. To protect yourself, it is essential to have a barrier between you and
the potentially infectious materials (PPE) personnel protective
Equipment)
Here is example of some PPE for biological and chemical hazard
Gloves
Face shields
goggles
Coat
Gloves
Goggles
face shields
Gloves should be made of
Latex, nitril, rubber , or other
Water impervious materials.
If a glove is damaged, don't use it
Anytime there is a risk of splashing
or vaporization of contaminated
fluids, goggles and /or other eye
protection should be used to
protect your eyes.
Face shields may be worn in
addition to goggles to provide
additional face protection. A face
shields will protect against splashes
to the nose.
Chemical Hazards
Chemical substance has one or more of the following:
1-May cause first degree of burn.
2- Corrosive
3-reactive
4- Toxic
5- Release large amount of energy.
6-Strong oxidizer: This may react produce fire or explosion.
7- Strong reducer: is an agent which removes O2 from material
such as chromic gas.
8- Producing gas, vapor, dust or smoke.
How do you know if a substance is hazardous?
1- Unless you know a substance is hazardous, so it consider as
hazardous.
2-Consult resource of new substance to identify a known
hazardous.
3-Labels on container as hazardous substance.
4- Material safety data sheets: it is required for all hazardous
chemicals and kept in file and available to all staff.
Types of chemical hazards effects
1-Violent reaction.
2- Fire.
3- Corrosive and irritative effect.
4-Toxic effect.
5-sensitization.
6-Behavioral effect.
7-Delayed hazard such as carcinogenesis.
Types of chemical hazardous substances
1- Flammable substance.
2- Corrosive substance
3- Irritative substance.
4-Toxic substance.
5-Highly toxic such as poison
6-Explosive.
7-Radioactive.
8- Carcinogenic.
Route of entry of chemical substances into body:
1-By inhalation into respiratory system.
2-By ingestion into gastrointestinal tract.
3-By contact to skin or mucous membrane.
4-By ocular (eye) penetration or contact.
Effects of chemical substances on body organs
1-Blood and haematopoietic system
 Chemicals : Carbon monoxide and cyanides
 Signs and symptoms:Cyanosis and loss of consciousness.
2-Cutaneous (skin) hazards
 Chemicals : Ketones
 Signs and symptoms: rashes and irritation.
3-Eye hazards:
 Chemicals : formalin and organic solvents.
 Signs and symptoms: conjunctivitis and corneal damage.
4-Hepatotoxins:
 Chemicals : uranium and carbon tetrachloride.
 Signs and symptoms: Jaundice and enlargement.
5-Nephrotoxins:
 Chemicals : uranium and hydrocarbon .
 Signs and symptoms:edema and proteinuria.
6-Neurotoxins:
 Chemicals :Mercury and xylene.
 Signs and symptoms: Behaviour changes.
7-Lung damage:
 Chemicals : Silica and asbestoses .
 Signs and symptoms: cough and shortness in breath.
8-Reproductive system:
 Chemicals: lead.
 Signs and symptoms: sterility.
Chemical substance frequently used in labs and hazards
1-Fixative:
 Chemicals: formaldehyde (formalin).
 Hazards: formalin is considered as irritant, sensitizer and potential
human carcinogenic.
2- Alcohols
- Chemicals: a- Ethyl alcohol is commonly used in processing and
staining of specimens in cytology and histopathology labs
b-Methyl alcohol
- Hazards: Ethyl alcohol is toxic and flammable Methyl alcohol is
highly poisonous.
3-Xylene:
-is commonly used in processing and staining of specimens
in cytology and histopathology labs.
- Hazards: Highly flammable and skin irritant
4- Acids
-Are Chemicals having pH value less than 7, such as HCl,
Sulfuric acid and Acetic acid.
-Hazards: Corrosive, burn of tissue on contact and blindness.
5-Alkalis:
-Are Chemicals having pH value more than 7, such as Ammonium
hydroxide and potassium hydroxide.
-Hazards: Corrosive, explosive when contact with acids, loss of
consciousness or death.
6- Carcinogens: Are Chemicals having the ability to cause cancer such as
Dyes and heavy metals
Toxic hazards and control measures:
Toxic materials may cause death or acute injuries, Highly toxic
substances may introduce to human body via ingestion (as
arsenic), skin contact (phenol) or inhalation (toxic gases:
CO2).Drops of mercury on bench tops and floor will be poison to
atmosphere in poorly ventilated rooms.
Control measures of toxic hazards:
Aim: to minimize the exposure to toxic hazards substances by:
1-Aways work in fume hood area with good ventilation.
2-Avoid contamination of skin with solvent. If this contact
happened, wash skin with soap and running water.
3-Avoid prolonged exposure to low concentrations vapor.
Sensitization and allergic hazards:
Some unexpected toxic effects of lab chemicals (Formaldehyde)
are development of an allergic sensitization in some individuals.
Corrosive and irritant hazards:
Corrosive substance is a chemical substance which destroys the
living tissues, e.g.: sulfuric acid, nitric acid and Sodium hydroxide.
Irritant is a chemical substance that causes local inflammatory
reaction or primary irritant without destruction of tissues, e.g
Acetone, benzene Xylene, ether ,methanol and Aniline.
Control measure:
1-Corrosive should be floor in separated sites.
2- Availability of adequate sources of water and eye washing
stations for rapid decontamination with Corrosive substance.
3- Use of protective bottle carriers will minimize contact with
corrosive substance.
Flammability hazards and control measures:
Sources of flammability hazards are Bunsen burner andsparks
from electrical instruments.
Control measures
1-No storage of organic solvent in refrigerators.
2- Heating of all solvent occur in fume hood rooms.
3-No contact of oxidizing substance which may be flammable
when contact with other materials.
Explosive chemical substance hazards
Explosives are a very serious danger in the lab.
Types of Explosive chemical substance
1-Highly Explosive chemical substances when heated . It may
cause directly Explosive or start fire. E.g. Hydrogen peroxide and
picric acid.
N.B. Never use picric acid near open flame.
2- Highly Explosive when dry E.g. Nitrocellulose
3-Potentaily Explosive when in concentration above 70% which
may cause burns such as perchloric acid.
4-Explosive when combined with other substances such as:
-Benzene with oxidents
-Glycerol with oxidizing agents.
-Potassium permanganate with acetic acid,HCl or sulphuric acid.
Control measures
1- Careful handling with extreme caution.
2- Storage the bottle of explosive substance in glassy tray
3- Disposable explosive substance is done by adding large amount
of cold water
4- A regular testing for all chemicals and removal of expired
substance.
Reactivity substances hazards:
Reactivity substance may be defined as unstable substance readily
to have violent changes or defined as a substance which may react
aggressively with water such as sodium and potassium.