MSHA reported a 51-year-old miner with 29 years' mining experience was fatally burned recently when a fire developed on the front end loader he was operating. The fire was due to a leak in a hydraulic hose that sprayed fluid onto hot engine components.

In order to reduce hydraulic hose hazards, equipment needs to be inspected regularly for exposed reinforcement wires, leaks, damaged or corroded fittings, excessive dirt or grease build-up and missing guards, shields and clamps, MSHA said.

The agency reminded operators of the following potential major hazards surrounding the use of hydraulic hoses:

Fine streams of pressurised fluid escaping from a damaged hose can enter the body and cause tissue damage;

The whip action of hose ends after a hose separates can strike a person with deadly force;

Fluid burns are another hazard, as fluid escaping from a damaged hose can burn skin even without igniting;

Escaping fluid exposed to a source of ignition may burn or explode – hoses should be guarded from exposure to ignition sources;

Hoses can contain conductive reinforcement material or conductive fluid – operators need to avoid routing near electrical equipment; and

Machinery driven or supported by hydraulics can move unexpectedly when a hose supplying that machine fails and results in loss of hydraulic pressure.

Temperature extremes, UV light and chemicals can degrade the rubber used in hydraulic hoses; and pressure surges above the hose working pressure will damage hose components, with potentially fatal consequences.

MSHA said hose life could be reduced by 90% when forced into an improper geometry, as it causes high stresses in the hose components that also reduce pressure capacity. Hose life is also reduced by rubbing against other hoses or objects, which wears down the outer cover and leads to corrosion of the reinforcing mesh.

The agency has advised mine safety operators to observe the following safety measures when dealing with hydraulic hoses:

Install abrasion protection such as spiral wrapping, sleeves and guards;

Install guards and shields around ignition sources (exhaust manifold, turbo, muffler, etc) and operator areas to keep out fluid if a hose fails;

Use properly rated hoses (working pressures are printed on the hose body) and hose fittings as well as proper hose lengths for the application. Replace hoses only with those that meet the equipment manufacturer's specifications;

Ensure proper hose routing to eliminate abrasion damage and exposure to ignition and electrical sources;

Use hose clamps where appropriate to prevent excessive free motion of hoses; and

Routinely change out hoses. Avoid costly environmental clean-ups, potential injury, unscheduled down time, and damage to other components in the system.