THE UNIVERSITY OF TENNESSEE AGRICULTURAL EXTENSION SERVICE AS-01-94 (rev 10/97)

Eye Safety on the Farm Timothy G. Prather Assistant Extension Assistant Agricultural and Biosystems Engineering Department

An estimated 7,500 eye injuries occur on American farms annually. These injuries are painful, expensive and can result in partial or total blindness. Human eyes are tough and have a certain degree of natural protection, but this natural protection is no match for chemicals or high-speed objects that may be hurled at them during farm and shop operations. Eye protection is needed in many daily farm activities, even when machinery and chemical safety steps are carefully followed and equipment is kept in good repair. Farmers often wear eye protection for certain tasks, yet many needless eye injuries still occur because they do not wear eye protection during all potentially hazardous operations. You can reduce your chances of having an eye injury. Good eye protection habits are easy to acquire. In fact, eye safety on the farm is as simple as "one, two, three. . ."

1. Know the hazards Most farm eye injuries occur in the course of regular farm work and during common activities where dust particles, flying objects and chemical spray are expected elements in the work environment. Activities where eye injuries may occur include harvesting, haying and other field jobs involving dust, chaff or other flying pieces; grinding, drilling, sawing, welding and other farm shop jobs; lumbering, orchard work, or trimming trees; operating, maintaining and repairing farm machinery; spray painting; and handling and applying agricultural chemicals.

2. Select the proper safety eyewear Different eye protection equipment is needed for different tasks. Eye protection should be selected on the basis of protection from a particular hazard. Safety glasses provide moderate frontal protection against flying particles. All prescription corrective lenses are by law impact-resistant; however, "impact-resistant" does not mean shatterproof. Safety glasses with lenses and frames meeting industrial safety lens standards offer greater protection. Close-fitting safety glasses with browguards and side shields offer better protection than plain spectacles. NOTE: Always wear safety goggles in addition to safety glasses when the possibility of heavy impact or chemical splash exists. Goggles offer both frontal and side protection, with excellent protection against most flying particles. They may be worn over regular glasses. Splash goggles with shielded vents offer excellent protection from chemical splashes, while unvented goggles should be worn when handling dangerous chemicals, such as anhydrous ammonia. Chipping goggles, with individual eye cups, offer maximum impact protection and are also recommended for use in extremely dusty activities. Face Shields are primarily for splash protection when working with chemicals and are intended to be worn over other protectors. Although they offer some protection against small flying particles, they are not made for heavy impact. When working with chemicals that are extremely dangerous to your eyes, like anhydrous ammonia, unvented goggles as

well as face shields are recommended. Welding goggles and shields with special absorptive or filter lenses provide protection against dangerous ultraviolet and infrared radiation, sparks, flying particles and other welding hazards. A welding helmet with a flip-up lens backed by a clear lens is very convenient and offers excellent protection during welding and chipping operations. Magnifying lenses are also available to help see the work better. Always wear goggles under welding helmets. Sunglasses are important protection for the farmer who works for prolonged periods out-of-doors as protection against the sun's harmful rays. DO NOT use ordinary sunglasses for impact protection or for protection against radiation from cutting and welding operations! You can obtain tinted lenses for safety glasses, goggles and face shields to protect you from bright sunlight, however. The lenses in eye protective devices should offer clear, comfortable vision without noticeable distortion. Eye protection devices should fit snugly and correctly. Straps, frames and other parts should be durable and fit comfortably. When selecting welding glasses, consult your welding supply dealer on the shade of filter lens needed for the type of welding you do. All protective eyewear must meet ANSI Z87.1 standards. This will be indicated on the packaging as well as on the eyewear itself. This approval is your assurance that the lenses and frames can withstand a certain amount of impact without failure. Basic requirements of ANSI Z87.1 are minimum lens thickness (3 mm for glass lenses, 2 mm for plastic lenses), lenses must pass impact testing, the frames must withstand certain strength tests and frames must not permit the lenses to be forced out toward the rear. •

Acetate has excellent chemical resistance and is primarily used in faceshields. Impact and heat resistance is not as good as polycarbonate.

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Glass has excellent chemical and scratch resistance. Glass lenses are available in various tint styles and may absorb over 99 percent of the UV light. Hot metal adheres to and invariably shatters glass lenses. Glass lenses are heavier and have lower shatter resistance than polycarbonate.

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Polycarbonate is the most common lens material today and is available in a wide variety of styles and tints. It is a plastic with good chemical resistance and excellent impact resistance (it may break, but does not shatter). Because polycarbonate is much

lighter than glass and absorbs over 99 percent of UV light, it can be worn for outdoor activities comfortably for extended periods. The main disadvantage of polycarbonate is that it scratches more easily than glass. •

Wire mesh face shields are a good choice for some activities, such as operating string trimmers and chainsaws, but must be worn over safety glasses or goggles. The mesh offers protection from small flying objects, but minimal protection from hard impact and no protection from chemicals and dusts. The advantage of wire mesh is that it has excellent ventilation and does not fog and or scratch.

Lens tints: The tint you select for your safety eyewear is as important as the lenses themselves. Select the tint that provides the protection you need with the least eye strain. •

Clear lenses are best for indoor and general use. Color perception is not affected by clear lenses.

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Gray lenses are good for work outdoors or in other very bright locations, and are available as solid gray or gradient tint (dark at top and almost clear at the bottom). Gray lenses do not affect color perception.

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Green - Generally used for protection against infrared radiation from hot work (welding, brazing, cutting, glassblowing, etc.), with the shade used depending upon type work being performed.

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Amber or yellow - increases contrast under certain lighting conditions, such as hazy or very overcast weather, but seriously alters color perception (objects will appear either yellow or black).

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Mirrored - Usually used on lenses for outdoor wear to help reduce glare. Sometimes reflective coatings are used on lenses for welding, but the lenses must be of the proper shade for the job.

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Polarized - Polarized lenses are not common in industrial safety glasses, but can be found in quality sporting eyewear meeting ANSI Z87.1 standards. Polarized lenses reduce glare from nonmetallic surfaces and make colors appear richer. They are excellent for outdoor use, especially driving and water sports.Laser safety glasses - Lasers are especially harmful to eyes because the light is focused in such a small beam and the retina is burned very quickly (much like focusing sunlight with a magnifying glass to burn paper). Glasses or goggles for laser use are specific to the type laser being used. NEVER look into a laser beam!

the vision you need for safe, efficient farming. 3. Wear safety eyewear - always The best eye protection devices made are useless if they are in your pocket or dangling from a machine at the time of an injury. You should know how and when to use eye safety devices - and use them. Wear them routinely whenever even the slightest possibility of an eye injury exists. Two of the more common complaints about protective eyewear are that it is uncomfortable and problems with fogging. Discomfort can be reduced by selecting the most comfortable safety glasses or goggles possible (they cost about the same as the least comfortable ones). Fogging results when warm, humid air contacts cool lenses. Wearing your safety glasses all the time will keep them warm and eliminate most fogging problems. Anti-fog coatings on the lenses also help. Keeping your vision up to par will also help reduce eye injuries and other farm mishaps. You can't avoid hazards if you can't see them. Periodic vision examinations will aid in the early detection of eye disease and help you maintain

You can reduce the possibility of an eye injury on your farm, it's as simple as "one, two, three ..." References: "Eye Safety of the Farm", American Optometric Association, 7000 Chippewa Street, St. Louis, Missouri 63119. Fundamentals of Industrial Hygiene, Third Edition. 1988. National Safety Council, 444 North Michigan Avenue, Chicago, IL 60611-3991. pp 77-92. Vallen Safety Supply Company, 1992 Safety Catalog. Vallen Safety Supply Company, 13333 Northwest Freeway, Houston, TX 77040-6086. pp 112-113, 131. OSHA Standards for General Industry, 29 CFR 1910.252(e)(2)(i). US Department of Labor. OSHA Standards for Welding, Cutting and Heating (draft of revisions). 29 CFR 1926.351. US Department of Labor. Safety in Welding and Cutting. ANSI/ASC Z49.1-1983. Amercan National Standards Institute.

CHOOSING EYE AND FACE PROTECTION Use the accompanying charts to select protective devices based on the hazards to be encountered. The Selection Chart offers general recommendations only. Final selection of eye and face protection is the responsibility of management and safety specialists. For maximum user acceptance, select the most comfortable and best looking protective eyewear that is suitable for the tasks and hazard exposures. Always remember that eye and face protection devices DO NOT provide unlimited protection.

NOTES: 1. Always consider the possibility of multiple and simultaneous exposure to a variety of hazards. Select protection based on the most severe hazard. 2. Activities involving heat may also involve optical radiation hazards. Protection from both hazards must be provided. 3. Faceshields must only be worn over primary eye protection. 4. Filter lenses for cutting, welding and heating operations must meet the shade requirements in Table 2. 5. Persons requiring prescription (Rx) lenses must wear either protective devices fitted with prescription lenses or designed to be worn over prescription lenses. 6. Contact lens wearers must wear appropriate covering eye and face protectors in a hazardous environment. It should be recognized that dusty and/or chemical environments may present an additional hazard to contact lens wearers. 7. Use caution when wearing metal framed eyewear in electrical hazard areas. 8. Refer to section 6.5 (Special Purpose Lenses) of ANSI standard Z87.1. 9. Welding helmets or handshields must be used only over primary eye protection. 10. Spectacles without sideshields are available for limited hazard use requiring only frontal protection, but are not recommended.

TABLE 1. EYE PROTECTION SELECTION CHART Activity Activity

I M P A C T

H E A T

C H E M I C A L D U S T

Chipping, grinding, machining, masonry work, riveting, sanding

Furnace operations, pouring, casting, hot dipping, cutting, welding

Protector type

Hazards

Flying fragments, objects, large chips, particles, sand, dirt, etc.

B, C, D, E, F, G, H, I, J, K, L, N

Spectacles, goggles, faceshields. See Notes 1, 3, 5, 6, 10.

Hot sparks

B, C, D, E, F, G, H, I, J, K, L, N

Faceshields, goggles, spectacles. For severe exposure see Notes 2 & 3.

Splash from molten metals

N

Faceshields worn over goggles H, K. See Notes 2 & 3.

High temperature exposure

N

Screen faceshields. Reflective faceshields. See Notes 2 & 3.

G, H, K

Unvented or indirectly vented goggles, eyecup and cover types.

Splashes Acid and chemicals handling, degreasing, plating.

N

Irritating mists

Woodworking, buffing, general dusty conditions

Protectors

Nuisance dusts

G

G, H, K

For severe exposure, add faceshield

Limitations

Protective devices do not provide unlimited protection. See Note 7

Spectacles, cup and cover type goggles do not provide unlimited facial protection.

Not Recommended Devices without protection from side exposures. Filter or tinted lenses that restrict light transmission, unless it is determined that a glare hazard exists. Refer to Optical Radiation.

Devices without protection from side exposure.

See Note 3.

Ventilation should be well protected from splash entry.

Special purpose goggles.

See Note 3.

Goggles, eyecup and cover types

Atmospheric conditions and the restricted ventilation of goggles can cause lens to fog. Frequent cleaning may be required.

Spectacles, welding helmets, handshields.

Electric arc welding

O P T I C A L R A D I A T I O N

O, P, Q

See Note 9. Welding helmet or welding shield. Lens shade 10-14.

See Note 9. Welding helmet or shield. Lens shades:

Gas torch cutting and welding

Welding

J, K, L, M, N, O, P, Q

3-6 Refer to Table 2.

Torch brazing

Glare

Lasers

4-8 See Note 3.

Cutting

Torch soldering

Protection from optical radiation is directly related to filter density. Select the darkest shade that allows adequate vision and task performance. See Note 4. Refer to Table 2.

3-4

B, C, D, E, F, N

Spectacles or welding faceshield. Lens shade 1.5-3.

A, B

Spectacle. See Notes 9 & 10.

Shaded, polarized or special purpose lenses as suitable. See Note 3.

B, C, D, E, G, H, I

Spectacle or goggle specifically intended for the laser being used.

Special purpose lenses specifically intended for the type and power level of the laser.

Adapted with permission from Vallen Safety Supply 1992 catalog.

Devices that do not provide protection from optical radiation. See Note 4.

TABLE 2. LENS SHADES FOR CUTTING AND WELDING Operation Shielded metal arc Shielded metal arc welding

Electrode size (inches)

Arc Current (amps)

Minimum shade permitted

Suggested shade

less than 3/32

less than 60

7

-

3/32, 1/8, 5/32

60-160

8

10

3/16, 7/32, 1/4

160-250

10

12

5/16, 3/8 Gas metal arc welding and flux cored arc welding

Gas tungsten arc welding Air carbon arc cutting

11

14

7

-

60-160

10

11

160-250

10

12

250-550

10

14

less than 50

8

10

50-150

8

12

150-500

10

14

light

less than 500

10

12

heavy

500-1000

11

14

less than 20

6

6 to 8

Plasma arc welding

light Plasma arc cutting

250-550 less than 60

20-100

8

10

100-400

10

12

400-800

11

14

less than 300

8

9

medium

300-400

9

12

heavy

400-800

10

14

Carbon arc welding:

-

-

14

Torch brazing:

-

-

3 or 4

Torch soldering:

-

-

2

Plate thickness

Gas welding:

Oxygen cutting:

in.

mm

light

under 1/8

under 3.2

4 or 5

medium

1/8 to 1/2

3.2-12.7

5 or 6

heavy

over 1/2

over 12.7

6 or 8

light

under 1

under 25

3 or 4

medium

1 to 6

25-150

4 or 5

heavy

over 6

over 150

5 or 6

NOTES: As a rule of thumb, start with a filter shade that is too dark to see the weld zone. Then go to a lighter shade which gives sufficient view of the weld zone without going below the minimum shade indicated in the table. In oxy-fuel gas welding or cutting where the torch produces a high yellow light it is desirable to use a filter that absorbs the yellow or sodium line in the visible spectrum.

SOURCES: ANSI Standard Z49.1-1983 and proposed revisions to the OSHA Standard for Cutting, Welding and Heating, 29 CFR 1926.351