(1) Explosive and flammable atmospheres. You must not use the tool in an explosive or flammable atmosphere.

(2) Unattended tools prohibited. You must never leave a tool unattended in a place where it would be available to unauthorized persons.

(3) Fasteners in hard, brittle areas. You must not drive fasteners into very hard or brittle materials including, but not limited to, cast iron, glazed tile, hardened steel, glass block, natural rock, hollow tile, or most brick. (See WAC 296-155-36313(10).)

(4) Fasteners in soft materials. You must not drive fasteners into easily penetrated or thin materials, or materials of questionable resistance, unless backed by a material that will prevent the fastener from passing completely through the other side.

(5) Fasteners in steel. You must not drive fasteners closer than 13 mm (1/2 in) from the edge of steel except for specific applications recommended by the tool manufacturer.

(6) Fasteners in masonry. You must not drive fasteners closer than 7.5 cm (3 in) from the unsupported edge of masonry materials except for specific applications recommended by the tool manufacturer.

(7) Fasteners in concrete. You must not drive fasteners into concrete unless material thickness is at least 3 times the fastener shank penetration.

(8) Fasteners in spalls. You must not drive fasteners into any spalled area.

(9) Fasteners in existing holes. You must not drive fasteners through existing holes unless a specific guide means, as recommended and supplied by the tool manufacturer, is used to ensure positive alignment.