- Certain chemicals that have no appreciable effects on plastics at room temperature may cause deterioration at autoclave temperatures and therefore must be removed. To avoid baking these contaminants onto the surface of the plastic, carefully clean all items and rinse thoroughly with distilled water before autoclaving.
- Because of differences in heat transfer between plastics and inorganic materials, the contents of plastic containers may take longer to reach sterilisation temperatures (typically 121°C). Thus, longer autoclaving cycles may be necessary for liquid contents. Cycle lengths can be determined only by experience with specific liquids and containers. Do not autoclave containers (except those made of fluoropolymers) containing detergent or wetting solutions. Note: Before autoclaving, just set cap or closure on top of the container without engaging threads.
- PP, PPCO, PMP, ETFE, FEP, and PFA can be autoclaved repeatedly at 121°C/15 psi. Cycle length should be at least 15 minutes at 121°C to ensure sterility.
- PSF and PC are autoclavable, but can be weakened by repeated autoclaving. If autoclaved repeatedly, PSF will eventually fail under high-stress applications. After repeated autoclaving, PC shows some loss of mechanical strength and may not function well under high-stress applications such as centrifugation. Limit PSF and PC autoclave cycles to 20 minutes at 121°C.
- PS, PVC, nylon, acrylic, LDPE, and HDPE labware and polyurethane tubing are not autoclavable under any conditions. Note: Some transparent plastics may absorb minute amounts of water vapor and appear cloudy after autoclaving. The clouding will disappear as the plastic dries.
Your labaoratory research demands that plasticware be sterilised for contamination-free use. Autoclaving plastics can be tricky, but here are a few tips to help: