Ch. 5 Lab Safety and sterilization methods

Key Terms/Concepts

  • Cage Washer: Equipment that operates at 180°F (82.2°C) for cleaning animal cages.

  • Biological Safety Cabinets (BSCs): Work cabinets designed to protect personnel from exposure to harmful microorganisms.

  • Fume Hood: A cabinet that protects users from chemical fumes by exhausting air outside the building.

  • Autoclave: A device that uses high-temperature steam under pressure to kill pathogens.

Key Equipment

Equipment Type

Description

Cage Washer

Operates at 180°F (82.2°C) for cleaning animal cages.

Biological Safety Cabinets

Designed to protect personnel from infectious agents; includes Class I, II, and III types.

Fume Hood

Protects users from chemical fumes; must not be used for biohazardous agents.

Autoclave

Uses high-temperature steam to sterilize equipment and kill pathogens.

Change Stations/Laminar Flow Cabinets

Used for cage changing; equipped with HEPA filters for air protection.

Key Safety Features

  • Cage Wash Safety Features: Includes door closure latches, windows in doors, and malfunction alarm systems.

  • Fume Hood Safety: Designed to only handle chemical fumes, not biohazardous materials.

  • BSC Class I: Protects user and environment but not the contents inside from contamination.

Key Methods for Autoclave Testing

Method Type

Description

Mechanical

Autoclave prints out a receipt indicating the cycle was completed.

Biological

Endospores placed inside the autoclave; survival indicates failure to kill other microorganisms.

Chemical

Autoclave tape indicates that the outside reached the required temperature, but not the inside.

Key Procedures/Protocols

  • Automatic Watering: Water is treated with acid, chlorine, reverse osmosis, or UV radiation to reduce contamination risk.

  • Use of BSCs: Required in facilities using infectious agents to protect personnel from exposure.

Facts to Memorize

  • Cage Washer runs at 180°F (82.2°C)

  • Autoclave temperature: 212°F (100°C)

  • Biological Safety Cabinets (BSCs) types: Class I, Class II (Type A1, A2, B1, B2), Class III

  • HEPA filter: High-Efficiency Particulate Air filter

  • Fume hoods must not be used for biohazardous agents.

Reference Information

  • Automatic watering methods: acid, chlorine, reverse osmosis (RO), ultraviolet (UV) radiation

  • Change stations or laminar flow cabinets protect animals with HEPA-filtered air

  • Fume hoods use fans to expel chemical fumes outside

  • Autoclave efficiency testing methods: mechanical, chemical, biological

Concept Comparisons

Feature

Class I BSC

Class II BSC

Class III BSC

Airflow

Draws in unfiltered room air

Draws in and HEPA filters air

Airtight, uses gloves for handling

Protection for User

Yes

Yes

Yes

Protection for Contents

No

Yes

Yes

Use Case

Enclosing equipment generating aerosols

General use with infectious agents

High-risk biological agents