Lab Safety Flashcards
What to know before working in the lab (8)
hazardous properties of materials and agents, safe handling and storage procedures (MSDS), proper use of equipment, emergency telephone number, reporting procedure, emergency response procedure, designated escape route, location and use of emergency equipment
While in the lab, perform procedures involving possible release of volatile toxic or flammable chemicals in a ___________________
chemical fume hood
Perform procedures involving the possible release of biohazardous aerosols in a ___________________
biological safety cabinet
Due diligence
doing everything reasonable to protect the health and safety of workers to prevent injuries or accidents in the workplace
ie. policies regarding health and safety, train workers to ensure awareness and competence in safe work practices
Types of hazards in medical laboratory (5)
physical hazards, chemical hazards, insidious/radiation hazards, biological hazards, psychological hazards
Physical hazards properties
volatility, density
chemical hazard properties
flammability, corrosivity, solubility, carcinogenicity, neurotoxicity
biological hazards properties
viability, pathogenicity, infectivity
psychological hazards
stress, abuse, working alone
Possible sources of physical hazards
fire, electricity, sharp objects, heavy objects and wet floor
Classifications of Fire extinguishers
Class A(green): puts out fires such as wood and paper class B (red): used on fires involving flammable liquids such as grease, gasoline, oil class c (blue): for use on electrically energized fire-is non-conductive class d(yellow): designed for use on flammable metals
fire requires three factors to burn:
heat, oxygen and fuel
scald
caused by moist heat in the form of hot vapor or liquid
burn
caused by radiation, chemicals or electric
how to handle sharp objects such as needles (4)
handle all needles and lancets carefully,
never lay down an uncapped needle,
uncap needle just prior to use, never recap, bend or break a used needle
and discard used needle or lancet biohazard container immediately after use,
cryogenics
-fluids that are liquified at a very low temperature -73.3 degrees celsius
, potential for pressure buildup in container
-most common cryogenic is liquid nitrogen
corrosive
aka caustic.
common corrosives are strong acids and strong bases;
these chemicals will injure body tissues by contact or corrode metal
ie. hydrochloric acid, sulfuric acid
caustic
aka corrosive by contact, these chemicals can burn or destroy tissue
ie. acetic acid and ammonia
poisonous
chemicals that cause immediate death if ingested (bromine ampules)
carcinogenic
chemicals known to cause cancer to humans or lab animals
mutagenic
aka crystal violet, cause genetic mutations, are typically carcinogenic
flammable chemical hazards and how to store
can catch fire easily, ignite at 37.8 degrees Celsius;
must be stored in a safety can or cabinet,
can only be heated by ether, methanol, ethanol, xylene, benzene and chloroform
what is the flash point for combustible chemicals and how should it be stored
has a flash point above 37.8 degrees Celsius; must be stored in a safety can or cabinet
PH
indicates the strength of many corrosives, the pH scale ranges from 0-14. pH 7 is considered neutral, acid is below 7 and alkalis bases are above 7. The more corrosive the substance the farther the pH from 7
hydrochloric acid
corrosive can cause burns on skin , vapour inhalation should be avoided
nitric acid
corrosive, releases yellow fumes, which are extremely toxic and damaging to tissue, overexposure can cause death, loss of eyesight. if ingested it causes extreme burns, may perforate stomach wall and cause death
sulfuric acid
corrosive, may cause blindness, if ingested may cause severe burns
acetic acid
severely caustic, continuous exposure to vapours can lead to chronic bronchitis, must be stored at room temperature in safety cabinet
Storing of acids
- in glass stoppered bottles
- if stored on shelves must not exceed capacity greater than 500 mL.
- large capacity bottles must be kept on floor.
- when transporting large bottles must be carried with rubber acid bottle carriers
- must not be stored with alkalis or other reactive chemicals
what is the rule when diluting acid with water
pour acid into water NOT water into acid
never place glacial _______________ in _____________ as it will freeze and the bottle will break
acetic acid, refrigerator
examples of bases
sodium and potassium hydroxide, ammonia, phenol, bromine ampules, iodine
sodium and potassium hydroxide
-alkalis
extremely hazardous even in low concentrations. may cause chemical caustic burns, permanent injury or scarring and blindness
ammonia or ammonium hydroxide
-alkalis
in concentrated form is caustic and can cause burns, they cause upper respiratory tract damage when inhaled
phenol
-an alkalis
liquid phenol causes burns with a blanching of the skin. do not use water to wash off phenol from the skin, use ethyl alcohol (absolute), which neutralizes the phenol by forming an ester
bromine ampules
- alkalis
- very common in laboratories
- poisonous and causes burns
Iodine
- alkalis
- does not react violently, but one should wear protective gloves when handling
storing and handling of bases
store in plastic containers, not glass (they form silicates). Do not store with acids or other reactive chemicals. they react violently with water, follow same guidelines for using acids
examples of explosives
picric acid, benzoyl peroxide, sodium azide
picric acid
handle with extra care because very explosive when dry, should be stored under water; found in brazil fixative
pyrophorous
substances that ignite and burn when exposed to air
General storage rules of chemicals
Chemicals should be arranged alphabetically
- store strong oxidizers and strong reducing agents separately,
- organic solvents should be kept in small quantities only.
How should Ether be stored?
should be stored in full, air tight, amber glass bottes or safety cans in the dark; because Ether can form explosive peroxides when exposed to air and sunlight. Also do not store in refrigerator.
How to store Sodium and Potassium metals and their hydroxides?
- store in plastic not glass bottles
- they must be kept dry and stored away from any water source; otherwise may catch fire spontaneously when wet
How to store Picric acid?
- it should be stored under water in a bottle with a stopper that is moistened before removal and on replacement.
- explosive when dry
How to store Mercury?
- stored in airtight containers away from direct sunlight and kept as cold as possible
- forms toxic vapor at room temperature
How should acids be stored?
- in glass stopper bottles in a glass drip tray
- must not contain more than 500 mL on shelf.
- larger volumes kept on floor
- Not stored with alkalis or other reactive chemicals
Ammoniacal Silver
forms explosive precipitates upon standing. do not store this compound
How to open acids or bases bottle?
-wear goggles, safety gloves and rubber apron
place bottle in sink, wrap absorbent towel or cloth over neck, then open carefully.
How to measure a dangerous chemical?
use a cylinder, automatic pipette or pipette and safety bulb. never mouth pipette.
How to pour dangerous chemicals?
keep the bottle below eye level
How to mix dangerous chemicals?
always add acid to water not water to acid.
How to transport large bottles of dangerous chemicals?
must be transported in acid bottle carriers to reduce the chance of accidental breakage.
How to handle carcinogenic substances?
wear disposable gloves, handle substances in a laminar flow hood. rinse hands in cold water before using soap after procedure is complete. Cold water closes pores and rinses carcinogenic away.
Drabkin’s reagent
used in hematology is extremely toxic (contains cyanide)
Ether
fumes are flammable. never use near an open flame
crystal violet
used in gram staining is clastogenic (causes breaks in chromosomes.) wear gloves when handling and do not mouth pipette
General Rules of disposing hazardous chemicals
- Never dispose several chemicals at the same time, in the same container or sink before checking their reactivity data
- rapidly flowing water must be used to flush the pipes when disposing chemicals down the drain
- spills are dangerous, isolate the spill with absorbent material, neutralize if necessary, mop up and dispose of all materials in a properly labelled disposal bag. ventilate area of spill
insidious and an example
aka hidden ie. aerosols
aerosol
the vaporization of the dispersion of liquid droplets, solid particles n a fine mist or spray ie. explosive type of cough or sneeze
lab procedures that create aerosols
grinding, blending, sonicating(applying sound energy to agitate particles ie. ultrasound), centrifuging
Sodium azide or picrates
insidious hazard
-can cause an explosion when it reacts with copper or lead piping
Mercury
insidious hazard
-contamination of a room can occur from breaking a clinical thermometer
extremely toxic
found in zenker’s fluid
-acute exposure may cause psychotic reactions, delirium, hallucinations and suicidal tendency
carcinogens and mutagens
often used in histopathology and chemistry labs, always perform in laminar flow hood
polycyclic hydrocarbons
well known as carcinogens
benzene
cause liver damage quickly and can cause cancer.
benzidine was used for occult blood testing; now known to be a dangerous carcinogen
Threshold Limit Value (TLV)
the concentrations of substances a person can be repeatedly exposed to during an 8 hour day without adverse effect
-often measured in ppm
Threshold limit value- Short term exposure limited (TLV-STEL)
the concentration of a substance a worker can be exposed to for a maximum of 15 minutes without adverse effect
Lethal dose 50% kill (L.D.50)
the dose of a substance when administered orally or intravenously to test animals kills half of them
-expressed in mg of toxic material per kg of body mass
Lethal concentration 50% kill (L.C.50)
the concentration of toxicant inhaled by test animals for a known period of time, which kill half of them
-reported in ppm
Radiation
energy that comes from a source and travels through material or space
ionizing radiation
has high energy to remove electrons from atoms or molecules
- results in the formation of a charged atom called an ion
- changing the chemical composition of the matter
- ie. xray, gamma ray
non-ionizing radiation
has enough energy to vibrate atoms, but not enough to remove electrons, including lasers, microwaves and ultraviolet radiation.
The degree of radiation exposure depends on these 4 factors:
- distance between the source of radiation and the individual
- amount of time of exposure
- type of shielding or protection used
- type of radiation; ionizing or non ionizing radiation
radiation acute effects include:
skin disorder, bone marrow disorder, digestive disorder, neuromuscular system disorder
radiation chronic effects include:
leukemia, other malignancies in the body
CNSC
Canadian Nuclear Safety Commission controls the standards for workplace exposure to radiation in Canada
Laboratory monitoring with a _______ and wipe tests to measure radiation exposure
Geiger-Mueller Counter
Disposal of Radioactive materials
radioactive reagents with a short half-life are poured down the sink
-other disposable are put into biohazard containers and held until background counts are reached, then treated as standard biohazard waste
Steps in handling major spills with radioactive material
- warn personnel and evacuate area
- decontaminate personnel
- turn off all services except lighting and ventilation
- close doors and windows
- inform supervisor
asepsis
free from infection or pathogens
medical asepsis
an object or area is clean and free from infection, non pathogens may still present, but pathogens are eliminated
microorganisms
tiny living animals or plants that cannot be seen by naked eye ie. bacteria, virus, parasites
growth requirements for microorganisms
- proper nutrition
autotrophs feed on inorganic or non-living and heterotrophs feed on organic or living substance - oxygen
aerobes need oxygen, anaerobes do not need oxygen - optimum temperature for each microorganism is body temperature 37 degrees celsius or 98 degrees fahrenheit
- darkness
- moisture
6.pH -most like neutral 7
majority of microorganisms do not normally cause disease True or false
true
pathogens, microorganisms that cause disease ________ the body, ________ and cause infection
invade, multiply
communicable disease
infection may spread from person to person
nosocomial or iatrogenic infection
occur from contact with infected patients, employees, visitors or contaminated equipment in the hospital
biohazards
infectious materials which present a risk or potential risk to humans
examples of biological hazards
blood, urine, feces, CSF, tissue, semen, synovial fluid, pleural fluid, amniotic fluid, sputum, peritoneal fluid
The infection process cycle:
- sources of infection(people, contaminated objects),
- means of exit(mouth, nose, throat, ears), —means of transmission (inhalation, ingestion, absorption, percutaneous exposure),
- means of entry (mouth, nose, ears, eye etc)
- susceptible host(this can be anyone)
how to break the chain of infection
stop infection at the source, eliminate means of transmission, reduce susceptibility of a potential host
personal protective equipment
lab coats and gowns, goggles, face shields eye shields, safety gloves, masks, respirators, automatic pipettes and pro pipettes, acid bottle carriers
Fume hood
not used in clinical medical labs, can be used when working with materials like strong base or acid, that generate fumes, gases, vapours and dust
biological safety cabinet
used to prevent the escape of aerosols into the lab.
- used when working with toxic chemicals, that generate dust or fumes.
- there are three types class 1, 2 and 3
class I biological safety cabinets
user is protected, the test or specimen is not.
- cabinet is a partial container unit
- can be used with an open front, an enclosed panel without gloves and with a panel with gloves
class II biological safety cabinets (laminar air flow hood)
- user and specimen are protected
- the most common BSC used in clinical labs
- airborne containments in the cabinet are prevented from escaping across the the front opening by a curtain or air supplied by a grill in the top of the cabinet
- open flames should not be used
class III biological safety cabinet
total enclosed
-provides the highest level of personal and environmental protection as well as test of specimen protection
safety can
these cans are explosion and fire proof, used to discard potentially flammable or explosive chemicals
safety emergency shower
used to wash off any acid, base, or toxic chemical from the body,
-used when large amounts of the body have been exposed to a chemical, should provide flow of water for at least 15 min
chemical spill kits
used to clean up accidental acid, solvent or alkaline reagent spill.
- most kits contain: absorbent material, a neutralizer for acids and bases, eye shield, scoop, brush and disposable bags
flammable storage cabinets
used to store flammable or combustible laboratory chemicals safely.
- has welded steel double wall construction with an air space between the walls.
- the door has a strong lock, leak proof sill, and a large FLAMMABLE KEEP AWAY label and hazard symbols on the front
Purpose of isolation
keep infectious agents from spreading outside the patient’s room
nosocomial infection
acquired infection while in hospital,
MRSA and VRE are the most epidemiologically important of antibiotic-resistant pathogens
MSRA
Methicillin-resistant staphylococcus aureus
VRE
vancomycin resistant enterococcus
Types of Isolation (5)
strict isolation, enteric isolation, wound and skin precautions isolation, respiratory isolation, reverse isolation
strict isolation
a private room with the door locked, where persons entering must wear gowns, gloves and masks.
-prevents the spread of infection spread by both air and contact
enteric isolation
used to prevent infections that are transmitted by direct or indirect contact with feces
-must wear gloves
wound and skin precaution isolation
designed to prevent transmission of infections by direct contact
-wear gloves
respiratory isolation
private room, and persons entering must wear masks, gloves and gowns are not necessary
-designed to prevent transmission through droplet or airborne means
reverse isolation
designed to protect the patients from infection.
-visitors must wear protective gear and constantly wash hands
Blood specimen collection techniques for isolated patients
- take only the equipment necessary into the room,
do not take blood collection tray into room
-procure specimen, label appropriately and affix “isolation” sticker on tubes
-place specimen in a clean plastic specimen bag located just outside the room
-do not step outside the room
-dispose of needle properly in the room
-remove protective clothing, seal the specimen bag, wash hands
-take specimen to lab
Standard Precautions
issued by CDC, set of procedures for dealing with patients under the assumption that all patients and all body fluids, substances, organs should be regarded as potentially infectious and potentially positive with hep B and HIV
Universal Precautions
a method of infection control in which all human blood and other body fluids containing visible blood are treated as if infectious
body substance precautions
all specimens, fluids, tissues, smears, blood, serum, plasma, swabs, must be considered potentially infectious. must wear gloves and coat when handle and deal with body fluid
procedure for accidental needle stick
- allow injury to bleed freely,
- decontaminate with iodine-providone for a minimum of 30 seconds
- cover with a waterproof bandaid
- report to supervisor in writing within 24 hrs
- do not milk the wound, may promote hyperemia
procedure for mucous membrane exposure
- flush the site with water for a min. Of 10 minutes
- report all exposure incidents, to an immediate supervisor with 24 hrs
- the employer must provide confidential medical evaluation and treatment to the employee
- source patient and employee tested for HIV and HBV.
- if source patient is HBV positive the employee’s immune status is determined and immune globulin shots may be given
Biosafety Level 1
suitable for work involving well characterized agents not known to consistently cause disease.
-minimal potential hazard to laboratory personnel and the environment
biosafety level 2
similar to biosafety level 1 with moderate potential hazard to personnel and the environment.
-agents such as hepatitis A, B, C, influenza, lyme disease, salmonella, HIV
Biosafety level 3
applicable to clinical or production facilities where work is done with indigenous or exotic agents which may cause serious or potentially lethal disease
-agents such as SARS, smallpox, yellow fever, TB
biosafety level 4
required for work with dangerous and exotic agents that pose a high individual risk of aerosol-transmitted laboratory infections, agents which cause severe to fatal disease for which vaccines and other treatments are not available
-agents such as dengue fever, ebola virus, hanta virus
disinfectants
products registered by the Canadian Environmental Protection Agency as being effective against HIV and HBV
ie. 1% hypochlorite, 2% glutaraldehyde
1% hypochlorite
universal intermediate chemical disinfectants aka bleach/javex
- effectively kills HIV, HBV, bacteria and fungi, but is inactivated by organic material
- this solution must be made daily
- not to be used on metal surfaces
2% gluteraldehyde
a high level and very potent disinfectant may be used on metal surfaces.
- effectively kills HIB, HBV and HCV
- must be made weekly and stored at room temperature
Formaldehyde
a high level disinfectant and sterilant used in both liquid and gaseous states.
- in liquid state kills bacteria, TB, Fungi, Virus and spores,
- in vapor, it is used to disinfect large areas
- full mask must be worn and two ppl must be present at all times
Phenols
low level disinfectants and should not be used in the laboratory to disinfect work areas, as they do not kill viruses and spores
Procedure when spill occurs on the body
- remove contaminate clothing
- vigorously wash exposed area with soap and water for one min
- obtain medical attention if open cuts are present
- report incident to lab supervisor
procedure when cleaning blood spills on hard surfaces
- isolate the area
- wear gloves and other protective equipment
- remove visible blood with disposable towels
- area should be decontaminated with appropriate germicide
- dispose contaminated towels and gloves in biohazard waste container
procedure when dealing with small spills
- cover the spilled material with absorbent towels
- gently pour disinfectant onto the paper towels, working in circular motion from outside to in
- wait 30 min
- remove the towels with forceps
- repeat steps 1-4
procedure when dealing with larger spills
- hold breath, inform others in area
- close windows and doors
- evacuate
- allow aerosols to disperse and settle
- follow procedures for small spills
biomedical waste disposal
waste must be segregated from general waste into categories: human anatomical waste, animal waste, microbiology lab waste, human blood and body fluid waste and waste sharps
packaging
-must remain intact and contained through handling, storage, transportation and treatment
properties of sharps container
must be sturdy enough to resist puncture under conditions of use to the point of disposal
- must be colour coded yellow and labelled with biohazard symbol
- must have lids that can be tightly secured
plastic waste holding bags
-sturdy enough to resist puncture under conditions of use and to the point of disposal
First aid for chemical injury of skin
- wash away the chemical with large amounts of water for at least 5 min, use a safety shower or hose
- remove the victims clothing from the areas involved
- do not apply ointments, creams etc
- apply a clean dressing bandage and get medical aid
First aid chemical injury to eyes
- wash the eyelids and affected face area with water for at least 15 min, use eye wash station (turn patients head to the side, hold eyelids open, make sure chemical doesn’t wash to other eye
- cover the eye with a dry, clean, protective dressing (do not use cotton) and bandage in place
- caution victim against rubbing eye
- seek medical attention
first aid for heat injury (burns)
- do not break blisters or remove tissue
- do not apply antiseptic or ointment
- just cover with bandage and seek medical attention
- if arms or legs are affected, keep them elevated
first aid for trauma
- apply direct pressure, by placing a hand over a dressing
- do not disturb blood clots after they have formed
- apply pressure bandage
- elevate wound above level of the patient’s heart
- seek medical attention
first aid for electrical shock
- remove patient from electrical source if you own safety is guaranteed. use a non-conductive (wood or plastic) device to push or pull patient away
- administer CPR if patient is not breathing or has no heart beat
- after re-establishing heart and lung function, elevate patient’s feet
- cover to keep them warm
- seek medical attention
first aid for accidental needle stick
- milk the wound, allow blood to flow freely
- wash and decontaminate with iodine for at least 30seconds
- apply waterproof bandaid
- report to supervisor within 24 hours
HCL
hydrochloric acid
NHO3
Nitric Acid
H2SO4
sulfuric acid
KOH
potassium hydroxide
NaOH
sodium hydroxide
