Health Hazards and Safety

Blast cleaning operations can be performed without risk to the health or safety of personnel if precautionary measures are followed rigorously. The health hazard that accompanies blast cleaning is silicosis, a disease of the lungs that results from the prolonged breathing of very fine particles of silica sand. In past years, improperly done sandblasting has been the cause of many cases of silicosis, which can be permanently disabling and even fatal. No matter how good the equipment, the operator should be examined by an accredited physician prior to employment and at least once a year thereafter.

Health Precautions. Air blasting of sand-free steel or iron castings and shot blasting of sandy castings produces enough fine silica to make the air dangerous to breathe. The blaster must be protected by a helmet supplied with air, special gauntlets, an apron, and often special leg protection. The blast room enclosure should be well lit (80 footcandles minimum illumination) and should provide ample clear space for walking and maneuvering by the operator. To meet current environmental standards, it should include ventilation and dust collection equipment to clean the air that is drawn through. The air supplied to the worker (about 0.17 m3/s, or 6 ft3/min) should be clean, odorless, dry, and free from gaseous contaminants. If taken directly from the compressed-air receiver, it is likely to be wet and malodorous. Use of a carbon monoxide monitoring device with an audible alarm is a mandatory requirement in any application in which breathing air is produced for the operator.

Pickling and Descaling

Robert M. Hudson, Consultant

0 0

Post a comment