Chapter 4 - Lab Safety

Question 1

Define sterilization and give examples

Answer 1

• process that kills all forms of life

- incineration, moist or dry heat, filtration, gamma radiation

Question 2

Define disinfection and give examples

Answer 2

• process by which MOST pathogenic organisms are killed
• physical: boiling, pasteurizing, ultraviolet light
• chemical: alcohols, aldehydes, phenolic compounds

Question 3

Define antiseptic

Answer 3

• disinfectants used on living tissue

Question 4

Sterilization: temperatures/time for the following processes:

• incineration
• moist heat
• dry heat
• filtration

Answer 4

• Incineration: burning to ash. Conducted at around 870-980 deg. C
• Moist Heat: about 120-130 deg. C for 30 minutes-1hr
  Ex: autoclave
• Dry Heat: 1.5-3hrs
• Filtration: use of micropore filters to remove contaminants

Question 5

Disinfectants

• resistant microbes (2)?
• factors that influence how well disinfectants perform (7)?

Answer 5

Resistant:

• C. diff
• fungal spores

Factors:

• Types of organisms present
• Temperature and pH of process
• Number of organisms present
• Concentration of disinfectant (1:10 typical concentration)
• Amount of organic material
• Nature of surface to be disinfected
• Length of contact time

Question 6

Disinfectants: Bleach

• dilution ratio?
• what type of microbes can it kill (4)

Answer 6

• 1:10 most common dilution ratio
• Bactericidal
• Virucidal
• Fungicidal
• Mycobactericidial
• • can kill TB

Question 7

What are some of the antiseptics we use in the laboratory/hospital (3)?

Answer 7

• Alcohol
• Iodine
• Silver Nitrate

Question 8

Waste Disposal

- what are two options for removal of infectious waste?

Answer 8

• Infectious waste is usually autoclaved or incinerated.

Question 9

Chemical Hygiene Plan

- what are the mandatory components (3)?

Answer 9

• Guidelines on labeling of chemical containers
• SDSs, which include
• Written chemical safety training and retraining programs

Question 10

Chemical Hygiene Plan: Guidelines on labeling of chemical containers
- what must be done if chemicals are moved from one container to another?

Answer 10

• If chemicals are moved from a stock container to a smaller vessel, the same biohazard label on the stock container must also be present on the smaller container

Question 11

Chemical Hygiene Plan: SDS

- what three pieces of information must they include?

Answer 11

• Information on the nature of the chemical
• Precautions if the chemical is spilled
• Disposal recommendations

Question 12

What are the 4 types of fire extinguishers and what type of fire are each of them used for?

Answer 12

• Type A—Is used for trash, wood, and paper.
• Type B—Is used for chemical fires.
• Type C—Is used for electrical fires.
• Type ABC—Is a combination extinguisher found in most laboratories.

Question 13

What are 6 elements that an exposure control plan identifies?

Answer 13

• Employee education and orientation
• Appropriate disposal of hazardous waste
• Standard precautions
• Engineering controls and safe work practices
• • Example of engineering control: safety caps on needles
• Personal protective equipment
• Postexposure plan

Question 14

Biosafety Levels (4)
- what are the necessary precautions for each level?

Answer 14

Level 1:
- No known potential for infection.
- Standard laboratory techniques.
Level 2:
- Include common agents of disease
- Primary containment equipment is used. 
Level 3:
- Organisms are transmitted by aerosol.
- Air movement is closely controlled.
Level 4:
- Includes exotic agents.
- Maximum containment is required.

Question 15

What are the two classes for shipping of infectious agents?

Answer 15

• Category A—Causes disease in humans and animals.

Category B—Includes biological substances.

Question 16

What are the four elements required when shipping infectious agents?

Answer 16

• Primary and Secondary Receptacle
• Absorbent material
• Tertiary container
• Labeling