I have a 8 month old. husband warms formula in microwave in bottles this safe for her or does he need to warm by boiling water & put in cup w/ bottle ?

Microwave: Warming milk in a microwave is not recommended because the milk can get very hot and burn the child

Scald risk: The microwave can superheat the milk to a scalding level that would not be evident when he holds the bottle. If he insists on using it the milk should be put in a separate container and the temperature checked by a thermometer or his finger when he transfers it to the bottle. Mouth burns are quite difficult to treat.