Yes, especially when opening and closing the hermetic seal. Please be mindful not to overstuff the Opsak or force it to close.To keep odor transfer to a minimum, try to keep the Opsak inside your Ursack when retrieving food or other scented items. Make sure to wash hands before and after touching the outside of the Opsak. Opsaks are disposable, recyclable, and must be replaced after extended use.