Sterilizing Techniques 4-H Veterinary Science Extension Veterinary Medicine Texas AgriLife Extension Service College of Veterinary Medicine and Biomedical Sciences Texas A&M System

Objectives Discuss the factors that must be considered when selecting a sterilization method Describe the process of preparing instruments for sterilization Describe heat sterilization Read and convert temperature scales Describe gas sterilization Describe chemosterilization

Sterilization Use of either physical or chemical procedures to destroy all microbial life that are resistant to disinfectants. Target microorganisms that exist on inanimate objects.

What type to use Technologies available Types of instruments Types of materials Time availability Expense Safety

Type of instrument sterilization Withstand moist heat Corrode with moist heat No heat method

Preparation Free of debris Soaking Detergent Scrubbing Ultrasonic cleaning Dry

Conversions Celsius to Fahrenheit

Example So 50°C = 122°F

Fahrenheit to Celsius

Example So 122°F = 50°C

Heat Sterilization Autoclave Most practical Use rust inhibitors Sodium nitrite Steam Time <15 # pressure °C 5 135°C Easy arrangement Not touching Corrosion may occur Also use a pressure cooker

Dry Heat Oven Dry instruments important 2 hours at 175°C Disadvantages Loss of metal hardness and strength

Direct Flame Disadvantage Loss of metal hardness and strength

Gas Sterilization Ethylene oxide Requires pressure container Requires several hours Uses Heat sensitive equipment Disadvantages Hazardous gas output

Chemosterilization Liquid glutaraldehyde Time efficient 30 – 60 minutes Uses Heat sensitive equipment Fiberoptic instruments Gastroscopes Endoscopes Laparoscopes Caution Handle carefully Rubber gloves required

Boiling Water Disinfectant Uses Stainless steel instruments Time 30 minutes

Storage Clean, dust free environment Aseptic condition