08 TECHNICAL INFORMATION | PRODUCT SECTION
STERILISATION
When preparing laboratory glass for sterile applications or as part of the cleaning process, sterilisation is a well-established process. DURAN® laboratory glassware is suitable both for autoclaving as well as for hot air and plasma sterilisation (H 2 O 2 ). Laboratory apparatus that has come into contact with infectious substances or microorganisms must be cleaned in accordance with the appropriate guidelines for handling these materials. As the case may be, this may include sterilisation. When carrying out sterilisation, especially of laboratory glassware, the following instructions should be observed: To avoid overpressure, all vessels should always be kept open. When sterilising media, the use of a membrane cap is recommended. Such a cap permits pressure equalisation through a PTFE membrane and hence the cap can be tightly closed. Consequently, the risk of contamination is greatly reduced. Alongside the standardised procedures described above, individually modified methods are also applicable to all DURAN® products, for example using higher temperatures. However, you must ensure, especially with bottles (due to the screw caps) that the permissible highest temperatures for the plastic used in the accessories is not exceeded.
WORKING UNDER PRESSURE
Only products whose design includes the appropriate geometry and wall thickness, and which are explicitly designated as such, are suitable for working under pressure and / or vacuum (e.g. filtering flasks, desiccators or flat flange vessels). When used under positive or negative pressure, and especially when also working with differential temperatures, additional care measures must be taken. Glass apparatus that is under pressure or vacuum should only be subject to further stress (e.g. significant temperature change) with extreme caution, as the individual resulting strains are additive and could readily result in failure.
To guarantee optimum user safety, the following points should be borne in mind:
• To avoid stresses in the glass, evacuated vessels or vessels under pressure should not be heated on one side or heated with an open flame. • When working under pressure the maximum figures indicated in the catalogue should not be exceeded. • Before using glass equipment under vacuum or pressure it must always be visually inspected to check that it is in perfect condition (no serious scratches, micro-cracks, abrasions, etc.). Damaged glassware should not be used for work under pressure or vacuum for safety reasons. • Never subject glassware to sudden pressure changes, e.g. always re-pressurise evacuated glass apparatus slowly. • Laboratory glassware with a flat bottom (e.g. Erlenmeyer and flat bottom flasks) should not be used under pressure or vacuum. • The plastic coating of laboratory bottles (DURAN® protect) has no influence on pressure resistance. These products are not designed for use under pressure. For pressure applications using laboratory bottles, the DURAN® pressure plus bottle should be used. The DURAN® pressure plus bottle is pressure resistant from –1 to + 1.5 bar due to a modified geometry and increased wall thickness.
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