Answer:
Snow is a better insulator than ice because snow contains air packets inside it and air is a good insulator of heat. Due to this, snow takes longer time to melt than the ice of the same mass.
Explanation:
The answer to the problem is 7/10
I would say you should use or test it once a week to ensure it is working properly in an active laboratory since it is a workplace with significant chemical hazards so it would give peace of mind to know on a quite regular basis that it can be relied on in case of an emergency like an eye flush for example.