Ohio Rev. Code § 1567.25: Explosives to be protected from contact with fire.

Whenever a workman is about to open a box, package, or keg, containing powder or other explosives, and while handling the same, he shall place and keep his lamp at least five feet distant from such explosives, and in such a position that the air current cannot convey sparks to it. No person shall approach nearer than five feet to any box, keg, or package, containing powder or other explosives, or within five feet of another person handling such explosives, with a naked lamp, lighted pipe, or other thing containing fire.

No workman shall refuse or neglect to comply with this section.