Histotechnology Safety Flashcards

These flashcards cover histopathology laboratory safety topics including biological hazards (HIV/HBV/TB/CJD), chemical regulations (Formaldehyde Standard/Right-to-Know), ergonomics, fire classifications, and waste disposal protocols based on Chapter 1 of the Histotechnology textbook.

According to the Centers for Disease Control and Prevention (CDC), what is the definition of "universal precautions"?

An approach to infection control whereby all human blood and certain human body fluids are treated as if they were infectious for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and other bloodborne pathogens.

Which specific body fluids require universal precautions regardless of the presence of visible blood?

Semen, vaginal secretions, synovial fluid, cerebrospinal fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid.

Under what condition should feces, sputum, and vomitus be treated with universal precautions?

Only if they contain visible blood.

What is the Occupational Health and Safety Administration (OSHA) requirement for the replacement and reuse of disposable gloves?

Disposable gloves must be replaced when contaminated or damaged; they cannot be washed or reused, and handwashing is required after removal.

What minimum level of respiratory protection does the CDC recommend for health care workers exposed to Mycobacterium tuberculosis?

A National Institute for Occupational Safety and Health (NIOSH) approved N95 filtering face piece respirator.

How soon must the hepatitis B virus (HBV) vaccination be offered to employees at risk of exposure?

Within $10$ working days of initial assignment at no cost to the employee.

What is the biological cause of Creutzfeldt-Jakob disease (CJD)?

Prions, which are abnormal "proteinaceous infectious particles."

What are the specific parameters for inactivating CJD prions using an autoclave according to Brown?

Autoclaving for $1$ hour at $121^\text{o}C$ and $2 \text{ kg/cm}^2$ (CAP recommends raising the temperature to $132^\text{o}C$–$134^\text{o}C$).

What chemicals are known to inactivate the CJD prion?

$1N$ sodium hydroxide for $1$ hour, concentrated formic acid for $1$ hour, or 5 \text{ %} sodium hypochlorite for $2$ hours.

How should steel instruments used for gross examination of CJD-suspected tissue be treated?

They should be treated with $1N$ sodium hydroxide for $1$ hour and then thoroughly washed with soap and water.

Which four types of waste are recognized as infectious by the CDC and the Environmental Protection Agency (EPA)?

1. microbiologic or culture material, 2. pathologic material, 3. blood, and 4. sharp objects.

What is the recommended disposal method for pathologic waste?

Incineration is the only recommended method (other infectious wastes may use steam sterilization).

What is ergonomics as defined in the provided text?

The science of adapting the working environment to the anatomic, physiologic, and psychological characteristics of personnel to enhance their efficiency and wellbeing.

How often should stretching be performed to help prevent musculoskeletal disorders (MSDs) in the laboratory?

At least every $20$ minutes.

What is the primary purpose of the Hazard Communication Standard ("Right-to-Know" law)?

To ensure that workers know the hazards associated with the chemicals in their workplace so that they can protect themselves.

What is the permissible exposure limit (PEL) for formaldehyde as an 8-hour time-weighted average (TWA)?

$0.75 \text{ ppm}$.

What concentration of formaldehyde is defined as the "action level" for an 8-hour TWA?

$0.5 \text{ ppm}$.

What is the maximum allowable short-term exposure limit (STEL) for formaldehyde over a 15-minute period?

$2.0 \text{ ppm}$.

What is the definition of LD50?

The calculated dose of a chemical substance expected to cause the death of 50 \text{ %} of an experimental animal population via any route other than inhalation.

What is a "designated area" in a laboratory setting?

An area (a hood, a room, or the whole lab) used for work with "select carcinogens," reproductive toxins, or substances with a high degree of acute toxicity.

How does the text define a corrosive hazard for disposal purposes regarding steel?

Substances that will corrode SAE 1020 steel at a rate $> 6.25 \text{ mm/year}$ at $55^\text{o}C$.

What are the three components of the "fire triangle"?

Fuel, an ignition source (heat), and an oxidizing agent (oxygen).

How is a Class A fire described and extinguished?

Fires involving ordinary combustibles (wood, plastic, paper, textiles) extinguished with water or water-based solutions.

What media are used to extinguish Class C fires?

Nonconductive media, such as halon, carbon dioxide, or dry chemical extinguishers.

What is the classification of a flammable liquid according to the National Fire Protection Association (NFPA)?

A liquid with a flash point $< 100^\text{o}F$ (Class I).

What is the flash point of Xylene?

$27.2^\text{o}C$.

At what height should flammable, corrosive, or toxic liquids be stored?

Never higher than eye level to prevent injury to the face and eyes if the container breaks or falls.

What precaution must be taken with picric acid to prevent it from becoming an explosion hazard?

It must be kept damp; if it contains < 10 \text{ %} water, distilled water must be added very carefully.

What is the official pH range required for neutralizing strong acids and bases before drain disposal?

Between $3$ and $11$.

In the NFPA 704 diamond, what do the blue, red, and yellow diamonds signify?

Blue signifies health, red signifies flammability, and yellow signifies reactivity.

In the NFPA rating system, what does a score of 0 represent versus a score of 4?

$0$ represents no hazard; $4$ represents an extreme hazard.

What are the two "signal words" used on chemical labels to indicate the severity of a hazard?

"Danger" (more severe hazards) and "Warning" (less severe hazards).