Primary cells and primary batteries: mercuric oxide cells, once used in hearing aids, cameras and instruments, now banned or restricted in most countries because of mercury content.

Mercury-containing batteries are restricted under the Minamata Convention and RoHS, so confirm that the destination permits import before shipping. Batteries are dangerous goods: lithium cells and packs fall under UN 3480/3481/3090/3091 (UN 38.3 test summary, state of charge limits, special packing), lead-acid under UN 2794/2800, nickel-cadmium or hydride under UN 2795/3496; provide MSDS, correct class labels and carrier approvals, and check destination battery marking and recycling rules.