The quality of steam supplied to the Autoclave steam steriliser is one of the most important factors in steam sterilization. Key attributes such as temperature, time and pressure are essential to ensure the success and repeatability of the sterilization cycle.

Steam quality testing is required as part of autoclave validation. Steam quality testing is a regulatory requirement and should be carried out early in the autoclave validation life cycle. The industry standard recommends “97%” pure steam. Unfortunately, this standard is not well defined and measured and cannot be used as an objective standard of steam quality. It is important that the steam quality meets the criteria established for the key attributes of the autoclave in order to be able to meet its intended use for fully sterilized items in load.

The main advantages of steam are:

1. Efficient process

2. Easy to control and maintain

3. Good porous load penetration

4. Faster than any other method

5. Do not contaminate the load in any way

6. No pollution will be released into the environment

Faults and problems may be encountered during the validation of the Autoclave Steam steriliser due to poor steam quality.

The most common problems associated with poor steam quality during autoclave steam steriliser validation include:

1. Wet steam

2. Noncondensable gas

3. Overheating

Wet steam can be caused by a number of factors that can negatively affect steam quality and sterilization cycle.

Some of the most common causes of wet steam include the following examples:

1. The water bubbled in the boiler

2. Too dense/too cold when placed in autoclave

3. The steam system was poorly designed

4. Insufficient quantity of steam trap

5. Steam trap and strainer too far from sterilizer

6. The regulator has a high pressure drop

7. Low section pipe between boiler and sterilizer

8. Inadequate insulation

9. Noncondensable gases are usually caused by leaks and cracks in pipes, separators or filters. Another common cause of noncondensable gas is insufficient degassing of boiler feed water.

Overheating is usually caused by:

1. Jacket temperature or pressure is too high

2. High steam pressure/temperature enters sterilizer

3. Large decompression and steam speed increase

All of these performance problems caused by poor steam quality have specific root causes that can be corrected by improving the quality of the steam supply and performing steam quality tests during validation.

Steam quality testing includes the following tests:

1. Steam drying

2. Noncondensable gas

3. Super hot

Vapor dryness is defined as the weight of the vapor, which is a group rather than liquid water.

A noncondensable gas is defined as the amount of steam by volume, which is not steam or water, but a gas like air that does not contribute meaningfully to the sterility of the load.

Superheat is defined as the temperature of steam higher than that of saturated steam with a given moisture content.

Autoclave implementation and validation is a complex and challenging activity for the industry. Autoclave steam quality is one of the key factors affecting the performance of autoclave. Steam quality testing is a key component in ensuring that the sterilization cycle is fully functional.

Validation of loads on the new autoclave requires evaluation of the technical capabilities of the new incubator and loads previously validated on the old autoclave. In summary, steam quality testing is a key component of autoclave validation. Poor steam quality can have a negative impact on the performance of autoclave steam steriliser and sterilization cycle.