Laboratory Safety and Biohazard Management Flashcards

What dilution of household bleach (5.25-6% sodium hypochlorite) is commonly recommended for decontaminating a blood spill?

Answer: 1:10

A 1:10 dilution of bleach provides approximately 0.5% hypochlorite, effective for blood-contaminated surfaces.

Which infectious agent is most resistant to standard chemical disinfection and routine autoclaving?

Answer: Prions

Prions resist conventional sterilization and require extended high-temperature autoclaving or treatments such as 1N sodium hydroxide.

What are the standard minimum conditions for steam sterilization in a gravity autoclave?

Answer: 121°C at 15 psi for at least 15 minutes

Standard steam sterilization uses 121°C at about 15 psi for at least 15 minutes, longer for dense waste loads.

Which organism's spores are used as the biological indicator to verify steam autoclave effectiveness?

Answer: Geobacillus stearothermophilus

Geobacillus stearothermophilus spores are highly heat resistant, making them the standard steam sterilization indicator.

When should a sharps disposal container be closed and replaced?

Answer: When about three-quarters full

Replacing containers at about three-quarters full prevents overfilling and needlesticks from protruding sharps.

A technologist drops a rack of blood tubes causing a large spill. What should be done first?

Answer: Alert others to keep away and put on appropriate PPE

Securing the area and donning PPE comes before absorbing, disinfecting, and removing broken glass with tools.

What is the appropriate way to clean up a small mercury spill from a broken thermometer?

Answer: Use a mercury spill kit with amalgamating powder

Mercury spill kits use sulfur or zinc powder to bind mercury, while vacuuming or sweeping spreads toxic vapor and droplets.