Safety Flashcards
Identify possible chemical, mechanical, and biological hazards in the histopathology lab.
○ Chemical: Carcinogens, Corrosive substances, Fire & explosive hazards, chemical spills
○ Mechanical: sharp instruments (microtome blades, razors, scalpels, needles), glass, electrical hazards, poor ergonomics
○ Biological: TB exposure, Cryogenic sprays, HIV, HepC & HBV, Creutzfeldt-Jakob disease (CJD)
List at least 5 commonly used toxic chemicals and identify the specific hazard(s) of each.
- Formaldehyde
- Xylene
- Alcohol
- Picric Acid
- Mercury
List reagents used in the lab for fixation and identify the hazards and proper disposal associated with each reagent.
○ Formalin: toxic, carcinogenic, irritant to skin and respiratory system
○ Glutaraldehyde: toxic, irritant, can cause respiratory issues
○ Ethanol and Methanol: flammable, toxic if ingested or inhaled
List reagents used in the lab for processing of tissue and identify the hazards and proper disposal associated with each reagent.
○ Xylene: flammable, toxic, harmful to the nervous system.
○ Acetic Acid: corrosive, can cause severe burns.
○ Bouin’s Solution: contains picric acid, which is explosive when dry; toxic
○ Paraffin Wax: can release fumes when heated; potential fire hazard
List 5 flammable or explosive compounds found in the lab.
Dry picric acid, benzoyl peroxide, ammoniacal silver, alcohols, xylene, toluene, benzene, methanol
Discuss proper storage of chemicals that are fire or explosion hazards.
Flammable (or toxic) liquids should be stored in glass containers only if the purity of the substance requires glass.
Should NEVER be stored higher than eye level
Outline measures to be taken for acid or alkali spills.
○ If floor drains are present, spill dikes should be available to prevent hazardous chemicals from entering the sewer system
○ Gloves, aprons, eye protection should be used in the event of a small spill
○ Spill kits should be available in the lab with absorbent pads for solvents, commercial neutralizers for acids and alkalis, and cleaning utensils
Describe safety measures that should be used because of biological hazards.
○ Appropriate barrier precautions must be used (gowns, gloves, masks) to prevent skin and mucous membrane exposure.
○ Disposable gloves be replaced when contaminated or damaged.
Identify the type of fire a Class A fire extinguisher should be used for.
○ Fires involving ordinary combustible materials such as word, plastics, paper, and textiles.
○ Class A fires can be extinguished with water or water-based solutions
Identify the type of fire a Class B fire extinguisher should be used for.
○ Fire involving flammable liquids and gases.
○ Class B fires require that oxygen be blocked from the fuel in order to be extinguished.
Identify the type of fire a Class C fire extinguisher should be used for.
○ Electrical fires
○ Class C fires must be extinguished with nonconductive media.
Identify the type of fire a Class D fire extinguisher should be used for.
○ Fires of combustible and reactive elements, such as metallic sodium, potassium, magnesium, and lithium.
○ Class D fires are difficult to control and extinguish because spreading and explosion can occur easily.
Define: Time-weighted average (TWA)
The amount of substance that a worker is exposed to, averaged over an 8hr period.
Define: Permissible exposure limit (PEL)
The maximum allowable 8hr time weighted average of exposure to a substance as defined by OSHA expressed in ppm.
Define: Short-term exposure limit (STEL)
The maximum allowable time weighted exposure for any 15min period during an 8hr work period
Define: LD50
○ Lethal Dose 50 - the amount of a poisonous compound needed to be lethal to half of the test population.
○ One means to assess the acute toxicity of the substance.
Define: Flash point
The lowest temperature at which a liquid produces enough vapors near the surface of the liquid or within the container used to form an ignitable mixture with the air.
Define Hazardous waste.
Waste that is dangerous or potentially harmful to our health or the environment
Define: Fire triangle
Fuel, oxygen, and an ignition source - the 3 elements necessary for a fire
Define: Ergonomics
○ The science of adapting the work environment to the anatomic, physiologic, and phycological characteristics of personnel to enhance their efficiency and wellbeing
○ Increased interest due to increasing numbers of cumulative trauma disorders or musculoskeletal disorders (MSDs) - carpal tunnel, trigger finger, tendonitis
Define: Universal precautions
Safeguards or barriers used to minimize or prevent contact with blood or other potentially infectious material
Define: Pictogram
A pictorial symbol for a word or phrase
Identify the PEL, STEL, and action level of formaldehyde.
○ Permissible Exposure Limit (PEL) = 0.75ppm over 8hrs
○ Action level = 0.5ppm over 8hrs
○ Short term exposer limit (STEL) = 2.0ppm over a 15 minute period
State the action to be taken if monitoring indicates that the TWA of formaldehyde exceeds the allowable limit.
Monitoring must be repeated every 6 months
Identify the purpose of the “Right-to-Know” law (Hazard Communication Standard).
Ensures that workers know the hazards associated with the chemicals in their workplace so that they can protect themselves
Identify the purpose of the Laboratory Standard (Occupation Exposure to Hazardous Chemicals in Laboratories).
requires employers communicate to their employees the potential dangers of chemicals with which they work and train employees in the use of proper safeguards for handling those chemicals.
State the effects of Creutzfeldt-Jakob disease (CJD) on the brain.
A prion (proteinaceous infectious particle) disease affecting nervous tissue - results in spongiform change in the cortex and subcortical white matter of the brain. Usually fatal within months after diagnosis
Outline a method for handling tissue from patients with CJD.
○ Brain sections should be fixed in NBF for more than 48hrs and whole brain should be fixed for 10-14 days.
○ Sections should be treated for an additional hour with concentrated formic acid and then placed in fresh formalin for 48hrs
○ This essentially inactivates the prions so processing can be handled routinely
○ Steal instruments should be treated with 1N NaOH for 1hr; gowns, gloves, and aprons should be incinerated/autoclaved; grossing table should be disinfected with 1N NaOH for more than 1hr
○ Instruments should then be thoroughly washed with soap and water
Substances labeled with this image are:
“Skull and crossbones”
Acute toxicity (fatal or toxic)
Substances labeled with this image are:
“Environment”
Aquatic toxicity (not mandatory)
Substances labeled with this image are:
“Exploding bomb”
explosives, self-reactive, organic peroxides
Substances labeled with this image are:
“Flame”
flammable, pyrophoric, self-heating, emits flammable gas, self-reactive, organic peroxide
Substances labeled with this image are:
“Health Hazard”
carcinogen, mutagenicity, reproductive toxicity, respiratory sensitizer, target organ toxicity, aspiration toxicity
Substances labeled with this image are:
“Corrosion”
skin corrosion/burns, eye damage, corrosive to metals
Substances labeled with this image are:
“Flame over circle”
oxidizers
Substances labeled with this image are:
“Exclamation Mark”
irritant, skin sensitizer, acute toxicity (harmful), narcotic effects, respiratory tract irritant, hazardous to ozone layer (not mandatory)
Substances labeled with this image are:
“Gas cylinder”
gases under pressure
