In every industrial environment, the safety factor is an important consideration. In some environments, it is of overriding importance. Some of the safety factors that need to be considered in coating application are as follows.
Safety in Surface Preparation
Workers using abrasive blasting equipment should be furnished with good equipment in proper working order. They should be equipped with air-filter masks to prevent their breathing dust and scale. Clothing should be adequate and safe. Safety shoes should be worn. Necessary goggles or safety glasses should be mandatory. Ear plugs or protective ear coverings should be worn.
No equipment should be operated in areas where it will create sparks that might ignite explosive or flammable materials. It should not be operated where abrasives, scale, or overspray will damage or interfere with the operation of other equipment.
Some materials, particularly older coatings that are to be removed for recoating of structures, are considered hazardous and require special safety procedures. This includes lead-based paints and asbestos-based coatings. These materials, often including the blast media, may not be left on site after removal. The participation of an industrial hygienist is often required to develop the plan for removal, capture, and proper disposal of these materials.
Safety in Materials
Coating materials are frequently flammable, explosive, or poisonous, and sometimes all three. The characteristics of any material used should be known in advance, and any necessary precautions must be taken and rigidly maintained during the progress of the job. In summary:
1) Coatings incorporating flammable or explosive materials should not be used in the vicinity of open flames, sparks, or electrical equipment. Every precaution should be taken to prevent accidental fire or explosion by prohibiting smoking, requiring the use of non-sparking tools, or whatever other safety requirements are appropriate.
2) When used in enclosed places, solvent concentrations should be kept both below the explosive limit and below the acceptable toxicity level. Both limits vary among materials, so safety rules should be a function of materials used. Ventilation of enclosed places should be continuous during the operation and for three hours afterward when explosive or flammable solvents are used. Safety-approved electrical equipment is mandatory.
Solvent vapors should be removed from tanks by suction because many vapors are heavier than air. Thus, the remotest and lowest ends of tanks should receive special attention. Workers should wear approved compressed-air masks. Shoes should have rubber soles and heels and no exposed steel nails.
Safety in Equipment
Whenever ventilation is a factor, it should be planned carefully and checked frequently. When necessary, automatic equipment should be used to make constant checks of air for poisons or explosive concentrations. All riggings, lifts, platforms, hoses, or any other equipment used on the job should be inspected and maintained in safe order. Rigging should be done by experienced operators.
Sources of Safety Information
Plant safety practices should be known and understood by plant paint crews or by outside crews doing contract work. In addition, the advice of plant safety engineers should be solicited and recommendations followed. Published information is available from technical and trade associations, testing bureaus, and most important, is usually printed on labels and instruction sheets received with materials and equipment. All personnel should be experienced and properly trained, including Operator Qualification (OQ) training, where applicable.
This article is adapted from Corrosion Basics—An Introduction, Second Edition, Pierre R. Roberge, ed. (Houston, TX: NACE International, 2006), pp. 462-464.