Final answer:
Vacuum checks on cryotainers should minimally be performed every 12 months to ensure integrity and optimal performance. These checks are essential for maintaining the vacuum quality necessary for proper storage of cryogenic materials.
Step-by-step explanation:
The frequency at which vacuum checks should be performed on cryotainers varies depending on the manufacturer's recommendation and specific usage. However, as a minimum, it is generally advised that vacuum checks be performed every 12 months to ensure the integrity of the vacuum insulation and to maintain optimal performance of the cryotainer. Neglecting these checks can lead to a decrease in the vacuum quality, which can compromise the ability of the cryotainer to properly store cryogenic materials.