Steam sterilization and Validation

Steam sterilization

Routine sterilization is a requirement for any system using a sterile filter. It is often carried out between batches or in a continuous process plant at prescribed intervals. In batch

Compressed Air Transmission and Treatment-0277

operation provided that the filter is kept pressurised and a small air bleed is allowed to flow continuously, several batches can pass before sterilization is carried out. The steam used must be saturated and free from additives or contamination, which implies its own sterile filter, see Figure 5. Steam sterilization is shown in the lower diagram of Figure 3.

A well designed system should last for 12 months before cartridge replacement is

Compressed Air Transmission and Treatment-0278

necessary; this probably means of the order of 100 sterilization cycles (according to the recommendations of the manufacturer). Typical cycles are shown in Table 1.The cost of replacement cartridges is small compared with the cost of a failure of the batch due to contamination, so replacement times should not be extended beyond 12 months.

Validation

Nothing should be left to chance when clean sterile compressed air is required for such applications as fermentation, genetic engineering, or pharmaceutical production. It is

Compressed Air Transmission and Treatment-0279

Compressed Air Transmission and Treatment-0280

essential that any filter used has been tested for integrity to ensure that it will fulfil its designed duty. The best way of testing for integrity is by a cloud of test particles in the critical rangeO.l to 0.3 micron. The test is based on creating an aerosol ofDioctyl Phthalate (DOP) in the critical particle range, challenging the filter with this and measuring any penetration with an aerosol photometer, downstream of the filter. DOP has been replaced by other substances because of possible health hazards and so corn oil or other oils are used giving the same type of particle spread when atomized. This type of validation test is carried out by the manufacturers and is not normally a procedure used by the end user

Related posts:

Case studies:Variable speed drives on a paper stock transfer pump
Benefits, drawbacks and operational issues:Resonance and rotor dynamics
Pumps:Reciprocating pump types
ACTUATORS:Piston- Type Cylinders
Health and safety:Conveying systems and Closed systems.
First approximation design methods:Empirical relationships
Review of pneumatic conveying systems:System requirements and Multiple pick-up
Review of pneumatic conveying systems:Closed systems
RESERVOIRS, STRAINERS, FILTERS, AND ACCUMULATORS:fiLTRATION
BASIC HYDRAULICS:USE OF HYDRAULICS
Control components in a hydraulic system:Pressure and temperature switches.
LINES, FITTINGS, AND SEALS:LINES, FITTINGS, AND SEALS
ENERGY TRANSFER BY HEAT,WORK,AND MASS:MECHANICAL FORMS OF WORK
THE SECOND LA W OF THERMODYNAMICS:THE CARNOT HEAT ENGINE
GAS MIXTURES AND PSYCHROMETRICS:SPECIFIC AND RELATIVE HUMIDITY OF AIR

Leave a comment

Your email address will not be published. Required fields are marked *