Signage Requirements in the US Mining Industry

In the minds of most people, mining conjures up an image of a rugged man in a construction hat walking out of a coal mine with black dust all over his face. While this may be a typical Hollywood depiction, reality is rather different – mining covers all minerals, not just coal.

The mining industry is regulated primarily by the Mine Safety and Health Administration (MSHA), created by the Federal Mine Safety and Health Act of 1977, more commonly known as the Mine Act. Title 30 of the Code of Federal Regulations (30 CFR) lays out the regulations that govern the mining industry, a number of which require signage to mark hazards. Sections 56 and 57 lay out the safety and health standards for surface and underground mines, respectively, and have nearly identical signage requirements.

Sometimes signage can make a potentially hazardous location into a legally workable one. Under 30 CFR §56.20011, a warning sign can be used as an alternative to barricades in potentially hazardous conditions. To remove the need for a barricade, the sign must sufficiently warn of the hazards within and the nature of those hazards. Additionally, when a hoisting operation is being performed, a “Men Working in Shaft” sign must be posted (§56.19107). This ensures the safety of both the hoistmen and those in compartments that are affected by such an operation. Signage can also indicate the closing of a mining location. §57.5045 requires that a sign be posted at inactive workings that are closed due to high radon levels. Exposure to high concentrations of radon can be fatal, so it is inadvisable to work in a radon-filled area. Additionally, signage can make smaller spaces legally acceptable. If vertical clearance above stair steps is less than seven feet, a warning sign needs to be posted that indicates a lower level of clearance (§56.11010).

Other signs indicate the prohibition of smoking and open flames in areas with flammability hazards. In 30 CFR §56.4502, smoking and other possible ignition sources are barred from battery-charging stations due to the potential for a fire. Similar signage is required in the more general case in which “a fire or explosion hazard exists” (§56.4101). In other words, the mine owners are responsible for warning of any possible fire hazard, both in battery-charging stations and otherwise.

As with battery-charging stations, warning signs must be posted when work is being done on power circuits (§56.12017). This helps in the lockout procedure and ensures that no one will accidentally reenergize a de-energized power circuit. Danger signs must also be posted at all major electrical installations in order to keep miners alert about possible electrical hazards (§56.12021).

Transportation A number of the CFR’s signage requirements relate to the transportation of materials to and from mines. On powder chests (§56.6133) and magazines that hold explosives (§56.6132), for instance, regulation mandates the usage of Department of Transportation (DOT) placards. These placards indicate the hazards associated with the contents of the powder chests and magazines, such as flammability and explosiveness, as outlined in Title 49 of the CFR. This serves to keep everyone around the materials safe. When hazardous materials are actually transported to or from the mine, the vehicles must be posted with warning signs that indicate the vehicle’s contents, These signs must be visible from every approachable direction (§56.6202).

In addition to these vehicular regulations, a series of more traffic-oriented regulations are also present in the CFR. For traffic control purposes, signs that warn of hazardous conditions are mandatory for areas around mines (§56.9100). Due to the relative instability of some of the explosives used in the mining industry (and for general safety purposes), the CFR also requires that all railroad crossings be marked (§56.9104). Signage can also be used in lieu of berms or guardrails in less travelled areas, so long as locked gates are also installed at the road’s entrance points (§56.9300).

Mine Offices Outside of the CFR, Section 109 of the Mine Act that there be an office at each mine, which is to be indicated “with a conspicuous sign designating it as the office of such mine.” The section also has a more general overview of signage requirements at mine sites, noting that a mine examiner should post a "DANGER’ sign conspicuously at all points which persons entering such hazardous place would be required to pass."

Sign Retroreflectivity

An article published by the Center for Disease Control indicates that there is a minimum required level of retroreflectivity for mining signs. The CDC’s article notes that “a minimum visibility of 3 m to 5 m is required for fire-escaping personnel familiar with the surroundings, and a visibility of 15 m to 20 m is required for personnel unfamiliar with the surroundings.” Signage at fire escapes must be visible from these distances in order to be compliant with regulations.

Mining’s independence from OSHA makes its regulations and signage requirements quite unique. Though MSHA does overlap with OSHA to some degree, the number of locations with mandatory signage is quite high in mines. This is due to the specific set of hazards that exist only in mining that make it an unusual industry, especially the highly dangerous and potentially fatal hazards that miners face on a daily basis. With these regulations in place, the number of mining accidents is minimized without impeding on the productivity of the mine.