1-2. ACCIDENT, FIRE, AND HEALTH HAZARDS
1-4. Accident Hazards
Paint operation accidents are caused by unsafe working equipment, unsafe working conditions, and careless personnel. Accidents can be caused by personnel who:
Accidents most frequently involve commonly used equipment. The most common and most serious accidents, by far, are falls either from a height or on the ground because of a loss of footing. Falling or moving objects are the next most serious hazard.
1-5. Precautions and Prevention
You should take nothing for granted. The proper use of equipment must be taught by qualified operators to all of your personnel. Regularly schedule refresher courses on the use of all equipment.
1-6. Equipment Check and Use
Enforcement of the following basic procedures in setting up and using equipment is imperative to assuring safety standards and maximum protection of all personnel.
a. Ladders. The following safety rules apply to ladders:
(1) Storage. When storing wood ladders you should—
- Protect them from the weather and the ground by storing them in warm, dry structures.
- Protect them with clear coatings only so that cracks, splinters, or other defects will be readily visible.
(2) Use. When placing or using ladders you should—
- Inspect all ladders frequently for loose or bent parts, cracks, breaks, or splinters.
- Use safety shoes on all straight and extension ladders. When metal ladders are used, shoes should be made of insulating material (Figure 1-6).
Figure 1-6. Ladder safety shoes
- Use only portable ladders that can be readily carried and placed by two men. Use the correct length of ladder; never splice ladders to form a longer ladder.
- Pretest all ladders and scaffolds before use by placing them horizontally, with blocks under ends, and bouncing in the center or walking along the ladder or scaffold.
- Use stepladders that are 10 feet or less in height. Avoid using stepladders as a straight ladder or standing on the top platform of ladders.
- Rope off all doorways in front of the ladder and place warning signs. Use hand lines to raise or lower tools and materials. Avoid reaching out from the ladder in any direction; instead, move the ladder as the work requires.
- Avoid using metal ladders in areas where contact with electric power lines is possible.
- Use extension ladders that have a minimum overlap of 15 percent for each section (Figure 1-7).
Figure 1-7. Ladder stability
- Place ladders so that the horizontal distance from the support structure to the ladder foot is at least one-fourth of the working length as shown in Figure 1-7. Be sure that the ladder is securely in place.
b. Scaffolds (Figures 1-8 through 1-15). The following safety rules apply to scaffolds and planking:
(1) Scaffolds. When setting up or using scaffolds, you should—
- Inspect all parts before use. Reject metal parts that are damaged by corrosion, and reject wood parts with defects, such as checks, splits, unsound knots, or decay.
- Provide adequate sills or underpinnings when erecting scaffolds on filled or soft ground. Be sure that scaffolds are plumb and level. Compensate for unevenness of the ground by blocking or using adjusting screws.
- Anchor scaffolds to the wall about every 28 feet in length and 18 feet in height. Do not force braces to fit. Use horizontal and diagonal-bracing at the bottom and at every 30 feet in height.
- Use straight-grained lumber. Drive all nails flush with the lumber so that nails are not subject to direct pull.
- Provide guardrails, regardless of working height, on the full length of the scaffold and also on the ends.
- Erect scaffolds so that ladders are lined up from top to bottom.
- Use ladders when climbing scaffolds.
- Use tubular-pole scaffolds made of 2-inch, olive drab galvanized steel tubing or other corrosion-resistant metal of equal strength. Use only experienced personnel to erect and dismantle them.
Figure 1-8. Double-pole or independent scaffold
Figure 1-9. Diagonal bracing on double-pole scaffold
Figure 1-10. Single-pole scaffold corner construction
Figure 1-11. Horse scaffold, two tiers (maximum height two tiers or 10 feet)
Figure 1-12. Outrigger scaffold with guardrail
Figure 1-13. Pipe scaffold
Figure 1-14. Pipe scaffold (roller-outrigging type)
Figure 1-15. Welded pipe scaffold with straddle braces
(2) Planking. To determine the nominal sizes of planking, use Table 1-1. When applying scaffold planking, you should—
Table 1-1. Safe center loads for scaffold planking
Use planking that has at least a 2-foot overlap. Secure planking well to the wood scaffold. Use planking of uniform thickness and lay it close together for platforms. Planking must overlap and be fastened at supports. Paint planking only at the ends to identify it and to deter its use for other purposes.
Test scaffolds and extensible planking (extended to working length) by raising them 1 foot off the ground and loading them with weights at least four times the anticipated working load.
c. Rolling Towers. The following safety rules apply to setting up and using rolling towers. You should—
- Inspect all tower parts before use. Do not use parts that are damaged by corrosion, deterioration, or misuse.
- Use a guy or tie off towers with heights that are more than three times the minimum base dimension, and fix towers at every 18 feet of elevation. Maintain the stability of towers over 25 feet high with outriggers or handling lines. Use horizontal and diagonal bracing at the bottom and at every height section.
- Provide unit lock arms on all towers. Do not use casters less than 6 inches in diameter. Do not extend adjusting screws more than 12 inches.
- Look where you are going when moving towers. Do not attempt to move a tower without sufficient help. Apply all caster brakes when the tower is stationary. Never ride towers.
d. Swinging Scaffolds and Boatswain's Chairs. The following safety rules apply to setting up and using swinging scaffolds and boatswain's chairs (Figures 1-16 through 1-18). You should—
- Read instructions on the proper use and maintenance of the equipment.
- Follow prescribed load capacities.
- Use stages at least 27 inches wide and supply them with guardrails (not rope).
- Use only experienced personnel to erect or operate stages.
- Check ropes and blocks before use by suspending stages 1 foot off the ground and loading with at least four times the anticipated work load.
- Check for nearby electric power lines before locating on the job site.
- Use power stages that have free-fall safety devices with hand controls in case of power failure.
Figure 1-16. Swinging scaffold with ladder (platform type)
Figure 1-17. Boatswain's chair (construction details)
Figure 1-18. Swinging scaffold (construction details)
e. Ropes and Cables. The techniques and illustrated procedures for proper knots and hitches are covered in Lesson 4. The following safety rules apply to setting up and using ropes and cables. You should—
Do not attempt to salvage rope or cable by splicing.
f. Pressurized Equipment. The following safety rules apply to all types of equipment used for spraying or blasting. You should—
- Use only approved equipment. Use remote-controlled dead-man valves on high-pressure equipment (60 pounds or higher). Valves should be activated by the same air used for blasting or spraying.
- Conduct a hydrostatic test at least once, preferably twice, a year.
- Test safety relief valves daily.
- Use a conductive hose. Ground nozzles, tanks, and pressure equipment when in use. The object being sprayed should also be grounded (Figures 1-19 and 1-20).
Figure 1-19. Grounding of tank and equipment
Figure 1-20. Grounding of blast nozzle
- Store hoses in dry areas.
- Avoid sharp bends (especially when curved around an object) when the hose is used. Secure high-pressure hoses no more than 10 feet from the operator.
- Avoid pointing a gun or nozzle at anyone or any part of your body. Hold the gun or nozzle by the grip and remove your fingers from the trigger when handling or carrying the equipment.
- Release all pressure before disconnecting any part of the equipment.
1-7. Regulations Affecting Protective Coatings and Their Use
Before we continue with fire and health hazards, you need to have an understanding of some of the regulations that have been passed and how they are affecting the products you may use. Most of the revisions made in Painting I are due to the changes brought on by regulations passed recently. Perhaps you have already encountered some of them. The following is a brief summary of the key regulations and how they have and will affect you and your work area.
a. Lead. Based on health hazards revealed in studies and past history, the US government enacted the Lead-Based Paint Prevention Act (LBPPA) in 1971. At that time, a protective-coating standard was set at 0.05 percent (500 parts per million by dry weight). Since 1977, the Consumer Product Safety Commission (CPSC) has limited the lead in most coatings to 0.06 percent (600 parts per million by dry weight). However, paint for bridges, marine, and industrial use may contain greater amounts of lead. Lead abatement and/or removal work on projects that have been identified as being lead-contaminated must be performed only by individuals who have received training and are certified. Currently, this work is civilian-contracted by the Department of Public Works (DPW). If you suspect the presence of lead in your work area, report it through the chain of command to DPW.
b. Volatile Organic Compounds (VOCs). In the 1970s, Congress passed the Clean Air Act and established the Environmental Protection Agency (EPA). The quality of the ozone layer topped the EPA's list. The Clean Air Act and the Clean Air Act amendments of 1990 are affecting the coatings industry by requiring the EPA to restrict emissions of VOCs into the atmosphere. Compliant coatings are being formulated by industries to contain higher amounts of solids and thus less solvent and to increase the use of water as the source of solvents.
c. Oil-Based Coatings. Oil-based coatings are highly flammable and are listed as class C (for exterior use only). Due to the flammability of oil-based coatings, the NFPA has established a standard for its use. The standard restricts the use of oil-based coatings to no more than 10 percent of the interior surface area. Although oil-based coatings have not been restricted from exterior use, the NFPA highly recommends the use of water-based latex enamel. You can expect further restrictions on the use of oil-based coatings. Your local regulations may have already started reducing their use. Be prepared for more changes as protective-coating products are reviewed. Your best approach is to check with your DPW, state, and local regulations. You are required to meet the strictest regulations, regardless of the level they originate from.
d. Material Safety Data Sheet (MSDS). The MSDS is prepared and provided with each shipment of chemicals received at the site. The Occupational Safety and Health Administration (OSHA) requires manufacturers to provide this informational sheet for coating materials, thinners, or other chemicals that you use and store at the job site. The MSDS must also be posted for easy viewing by users and OSHA inspectors. Your painters need to be instructed on how to read and interpret the information. (See Appendix E for sample MSDSs.) The MSDS may be used for several purposes, such as—
1-8. Fire Hazards
Most paint products are highly flammable and extremely dangerous when they or their vapors are exposed to open flames, sparks, or excessive temperatures. Flammable liquids and vapors, especially the latter, are by far the chief causes of fire and explosion. Forms of flammable liquids and vapors are solvents, oil paints, and some components in other paints.
a. Solvents. Most paint products are flammable because of the solvents they contain. Solvents are highly volatile and some will flash in the presence of a flame or at temperatures below the safe temperature recommended on the paint can label. Because of this, they may be safe in cold weather yet be potentially dangerous in midsummer. It is safer to use paint materials that will flash at temperatures significantly higher than the painting temperature since environmental changes can quickly change a safe condition to a dangerous one. For example—
(1) Safety and blending of flash points. Mineral spirits with a flash point of 105°F are considerably safer to use than a varnish that is a naphtha and benzene compound which has a flash point of 50°F or less. Furthermore, paint, varnish, or lacquer that contains a mixture of solvents will flash at a temperature close to that of the most volatile solvent. This is because the most volatile solvent vaporizes more quickly than the others.
NOTE: A low-flashing paint material cannot be made safe by blending it with another paint having a higher flash point.
(2) Vapor concentration and static electricity in enclosed spaces. Low-flashing solvents volatilize or vaporize readily, and they are most likely to bring about high concentrations of vapor in enclosed spaces. This is especially true when you are spraying, since spray paints usually contain low-flashing solvents to accelerate drying. A spray gun, which applies from a pint to a quart of paint per minute, will cause a much greater concentration of vapor than a dozen brush painters. Every gallon of solvent in the paint is capable of creating large amounts of potentially dangerous gas. This condition is even more dangerous in confined spaces. If a critical ratio of solvent vapor to air is reached in this space, it is possible to cause an explosion in the presence of a flame or spark. This is why you must ground spray equipment to prevent ignition by a spark from static electricity.
(3) Vapor concentration and flash points in enclosed spaces. Solvent vapors, which are heavier than air, will move along the ground for dozens of yards from the area of application. For this reason, you must extinguish all flames anywhere near the painting area. The flash points and flammable vapor/air limits of common paint solvents are given in Appendix D.
b. Oil-Based Paints. Many exterior paints for wood and steel are based on raw or refined linseed oil. These represent a very definite fire hazard if you allow paint-soaked waste or wiping rags to remain lying around. As the paint dries, the oxidation of the oil can cause the temperature to rise to the point where the rag or waste material will ignite spontaneously. The situation is especially dangerous if rags are contaminated with pure raw or boiled linseed oil (Figure 1-21).
Figure 1-21. Keep combustibles stored in tightly covered, metal waste cans
c. Other Paints. The majority of paints that you apply on site contain high-flashing solvents (over 100°F); therefore, they are relatively low in hazard and require only normal precautions. However, some finishes represent an abnormal fire and explosion hazard. Among these are spray finishes with low- flashing solvents as described above. Others are nitrocellulose lacquers that burn rapidly because of the nitrocellulose present and two-component products that are subject to spontaneous combustion if mixed in large quantities.
1-9. Precautions and Prevention.
You, as the supervisor, must ensure that certain general safety rules regarding fire and explosion hazards are applied to all situations.
1-10. Specific Safety Measures
It is important that you and your painters perform in a safe manner by observing safety measures and fire-prevention safety rules.
a. Safety Measures. You must ensure that the following safety measures are practiced by your personnel.
Table 1-2. Proper fire extinguishers
b. Fire Extinguishers, Descriptions, Class Uses, and Directions. With the exception of water, the three most common types of fire extinguishers are—
(1) CO2 extinguishers (Figure 1-22) may be used on Class B and C fires. To operate a CO2 extinguisher, pull the seal locking pin and open the operating valve. Direct the CO2 toward the base of the fire with a sweeping motion.
(2) Dry chemical extinguishers may be used on Class B and C fires. These units contain a dry powder, usually sodium bicarbonate, and an activating agent of CO2 or nitrogen gas. Do not use these units on trash fires. To operate the extinguisher, remove the locking pin, open the cartridge discharge valve, and squeeze the nozzle handle.
(3) Foam extinguishers (Figure 1-23) may be used on Class A and B fires. For a fire involving liquids, invert the extinguisher and direct the hose so that the foam is played over the surface of the fire. In a solid-material fire, direct the stream of foam to fall lightly on or flow over the burning surface of the material.
Figure 1-22. CO2 fire extinguisher
Figure 1-23. Foam fire extinguisher
c. Fire-Prevention Safety Rules. Observe the following safety rules in connection with fire prevention:
1-11. Health Hazards
A variety of ingredients used in the manufacture of paint materials are injurious to the human body in varying degrees. While the body can withstand nominal quantities of most of these poisons for relatively short periods of time, continuous exposure or overexposure to them may have harmful effects. Furthermore, continued exposure to some material may cause the body to become sensitized so that subsequent contact, even in small amounts, may cause an aggravated reaction. To this extent, these materials are a very definite threat to the normally healthy individual and a serious danger to persons with chronic illnesses or disorders.
a. Causes of Health Hazards. Hazardous materials are divided into two major groups; they are toxic materials and dermatitic (skin-irritating) materials.
(1) Toxic materials. Toxic materials may be present in the form of vapor, dust, or spray mist and may enter the body either by breathing, swallowing, or absorbing through the skin. Possible symptoms of excessive exposure are irritation of the nasal membranes, headache, dizziness, loss of appetite, nausea, and fatigue. Typical examples of toxic materials are as follows:
Pigments. The most common toxic pigments are lead-containing compounds and zinc chromate. Lead may be present in white or tinted paints as white lead; in primers as lead chromate, red lead, or basic lead silica chromate; and in paint dryers. The CPSC banned lead-based paints for residential use in 1978. Almost all paint manufacturers have removed toxic pigments (such as lead) from their products, and many good alternatives are available. Refer to the product specifications for the analysis, and instruct your personnel to take proper precautions if the level of toxic pigment is greater than 1 percent of the total weight of solids in the dry paint film.
Solvents. The maximum allowable concentrations (threshold-limit value [TLV) for common paint solvents are listed in Appendix D. Among the most toxic solvents are benzol (benzene), methyl (wood) alcohol, and chlorinated solvents (such as carbon tetrachloride). However, these solvents are rarely used in common paint materials.
Binders. Some binders or vehicles are toxic; for example, epoxies, amines, polyurethanes, and polyesters. Caution your personnel to avoid breathing the fumes or spray or contacting binders with skin. In addition, personnel should always wash their hands and face thoroughly before eating or smoking.
VOCs. The compounds are defined by the EPA as a group of chemicals that react in the atmosphere with nitrogen oxides (combination compounds from automotive emissions and burning of fuels) in the presence of heat and sunlight to form ozone and air pollutants. Ozone in the lower atmosphere also is known as smog, a pollutant detrimental to plants and humans. The EPA has been directed to regulate VOCs. Control-technique guidelines were issued in the 1970s. Regulations are being developed at the national level. State and local governments have passed regulations; however, permissible VOC emissions vary widely, depending on the generic type of protective coating and the location where it is applied. When you are checking for acceptable coating products, look for the statement "VOCs as applied" rather than the amount of VOCs in the can. New protective-coating products are being added to the VOC regulations list, and new rules are being established. Check the VOC regulations in the area where you intend to apply the protective coatings before selecting a product.
(2) Dermatitic materials. Dermatitic materials affect the skin. The skin becomes irritated, and if left untreated, infection can set in and progress to allergic sensitization and finally to incapacitation and hospitalization. The following are typical examples of dermatitic materials:
Solvents. All solvents tend to remove natural oils and fats from the skin, leaving it dry, chapped, irritated, and sensitive to infection. Milder solvents, such as mineral spirits, are not as irritating to the skin as stronger solvents, such as turpentine, xylol (xylene), methyl ethyl ketone (MEK), or methylene chloride. (Methylene chloride is the most common solvent used in nonflammable paint removers.)
Resins and resin hardeners. Epoxy resins, amine hardeners, and some urethane and polyester resins irritate the skin and should be handled with special care.
Corrosive agents. Corrosive agents in paint removers and paintbrush cleaners (such as phenol acid [carbolic acid] and alkaline cleaners) and acid components of wash primer are also dangerous if handled carelessly.
b. Precautions and Prevention. You can easily avoid health hazards by using a common-sense approach of avoiding unnecessary contact with hazardous materials and by strict adherence to established safety measures.
c. Specific Safety Measures. The following rules should be strictly observed by all personnel:
1-12. Emergencies and Health Services.
a. First-Aid Emergencies. Provide well-stocked, first-aid kits containing fresh materials and make them easily available and accessible during any painting operation. Ensure that all personnel are able to give emergency first aid. However, report any illness to the medical and industrial safety departments, regardless of whether or not it appears to be serious. Some toxic materials do not take full effect for days.
b. Health Services. Health services include working with the installation medical department, performing medical exams, and managing medical records.