Which materials are generally not recommended for use in steam sterilization?

Plastic materials are generally not recommended for use in steam sterilization due to their varying tolerance to high temperatures and moisture. Many plastics can warp, melt, or degrade when exposed to the intense heat and steam of the sterilization process. This can not only compromise the integrity of the instruments but also lead to contamination risks if pieces of the material become dislodged.

In contrast, glass and metal instruments, for instance, are usually suitable for steam sterilization because they can withstand high temperatures without being damaged. Textiles are often used in steam sterilization as well, provided they are appropriately packaged and prepared to allow steam penetration. Ceramic items can also withstand steam sterilization but may be more sensitive to thermal shock. Hence, when selecting materials for steam sterilization, it's essential to consider their physical properties and their ability to endure the conditions of the process.