Industrial Safety Eyewear
OSHA 29 CFR 1910.133 General Requirements (1)
(1) each affected employee shall use appropriate eye or face protection when exposed to eye or face hazards from flying particles, molten metal, liquid chemicals, acids or caustic liquids, chemical gases or vapors, or potentially injurious light radiation
OSHA 29 CFR 1910.133 General Requirements (2)
(2) each affected employee shall use eye protection that provides side protection when there is a hazard from flying objects. Detachable side protectors (clip on, slide on side shields) meeting the pertinent requirements of this section are acceptable
OSHA 29 CFR 1910.133 General Requirements (3)
(3) each affected employee who wears prescription lenses while engaged in operations that involve eye hazards shall wear eye protection that incorporates the prescription in its design, or shall wear eye protection that can be worn over the prescription lenses without disturbing the proper position of the prescription or the protective lenses
OSHA 29 CFR 1910.133 General Requirements (4)
(4) Eye and face PPE shall be distinctly marked to facilitate identification of the manufacturer
OSHA 29 CFR 1910.133 General Requirements (5)
(5) Each affected employee shall use equipment with filter lenses that have a shade number appropriate for the work being performed for protection from injurious light radiation. The following is a listing of appropriate shade numbers for various operations
ANSI Z87.1 lens impact
-1" (2.4 oz) steel ball dropped from 50" onto lens horizontal front surface; lens shall not break
Basic impact non plano lenses
-3.0 mm thickness minimum -not tested to same level of impact as high impact lenses -lenses do not need to be marked with a "+" -pass the industrial DBT (1" steel ball at height 50") -all glass lenses are to be tested; plastic lenses batch tested
how to get a copy of the new std ANSI Z87.1?
-ANSI -ASSE (American Society of Safety Engineers)
Industrial Eyewear
-OSHA regulates industries -all industrial eye & face protectors will meet Z87.1 -spectacle frame and lens must both meet Z87.1 -industrial lenses in a dress frame or dress ophthalmic lenses in an industrial frame do NOT meet the std
ANSI Z87.1 Lenses requirements
-a needle (135x17) must not penetrate lens surface -prescription follows Z80.1 tolerances -cannot mix safety lens with dress frame or vice versa -lens tints
Types of electric arc
-cabon arc welding (carbon electrode) -shielded metal arc welding (use in automotive & machine shops, flux-coated metal rod) -gas tungsten arc welding (tungsten electrode) -gas metal arc welding (metal wire electrode, quick welding process) -flux core arc welding (flux wire electrode) -plasma arc welding
ANSI Z87.1 Lens tints
-clear lenses generally recommended but tint not completely restricted -regarded as protective filter, not cosmetic tint -if tinted, must meet Z87.1 stds for min to max visible light transmittance and max UV and IR radiation transmittance -tint shade number must be clearly ID'd -higher shade #: darker lenses; usually green color to filter UV/IR -transmission b/t right and left lens must be within 10% of each other -photochromic lenses not necessarily disallowed or officially allowed; lenses must be monogrammed with letter "v" -lenses that are tinted for special purpose situations must be monogrammed with the letter "S"
Welder's helmet
-cylinder shaped to protect fact, forehead, ears, front of neck with opening just for eyes -made from fiberglass material -designed to permit raising of headgear when not welding -opening (size: 2 x 4.5 in) permits various appropriate flat filter plates -typically 5 filter plates in place: outside --> polycarb --> protective plate --> gold metallic filter for IR --> next plate for UV --> next for appropriate visible spectrum absorption --> last another clear polycarb -welder recommended to wear protective spec under helmet
Absorptive lenses- occupational use
-designed to protect from potential chemical, mechanical, and radiation damage or injury -must absorb both UV and IR radiation -transmit primarily in the mid-spectrum -lenses are bluish green or greenish yellow -level of transmittance in mid spectrum must be appropriate for task -occupations: welders, lasers, glassblowers, blast furnace operators
welding lenses recommendations
-electric arc welding: shade # 10-14 -gas welding: shade # 10-12 for heavy welding, shade # 5 for lighter welding -brazing: shade # 3 or 4 -soldering: shade #2 -general sunwear: shade # 1.5-2
Welders
-extremely hazardous occupation with potential ocular injury -hot metal particles are constantly expelled in all directions -exposed to a broad spectrum of radiation -over 0.5 million welders in US -requires good radiation and physical protection
welding components
-flux: a compound that coats welding electrode to aid in the process of preventing oxidation at the weld point -electrode: a metal rod, metal wire, carbon rod or non-consumable metallic rod (electric current flow) -welding rod: a wire or rod assisting the welding process -shielding: process of using inert gases to flow through the electrode holder to prevent oxygen flow to the welding point
High mass, low velocity test
-frame with 2.0 mm plano lenses mounted on special head form -17.6 oz (1" diameter) pointed projectile dropped through a 51.2" tube -frame and lens must remain intact -no contact may be made with head form
low mass, high velocity test
-frame with 2.0 mm plano lenses mounted on special head form -frame is shot from front and size with 1/4" steel ball traveling at 150 fps -upon impact no part of the frame is to contact the eye on head form -no parts or fragments may be ejected
Welding lenses- Class I
-general purpose -significant UV and IR reduction
Types of basic impact lenses
-glass -CR39
Didymium lenses
-greenish blue or rose brown color -dichroic- exhibiting different colors under various light sources -incandescent: rose color -fluorescent: greenish blue -cerium oxide with didymium -designed primarily for glass blowers to filter out the Na+ light -filters out the yellow flame (sodium flame) -absorbs in the 570-590 nm range; primarily an occupational lens -only available in one piece multifocal lenses
OSHA's job
-has oversight in workplace for worker health and safety -federal and state OSHA's may inspect, cite, and fine employers -action may be spontaneous or in response to whistle blower complaint
welding lens transmission
-higher shade # , darker the lens or less transmission
ANSI Z87.1 lens retention test
-lens must not be displaced from frame
High impact non plano lenses
-lenses must not be less than 2.0 mm thick -lenses must have the "+" mark -Rx lenses are not individually tested -Note: for plano high impact lenses, no thickness requirement
Thermite
-limited use -chemical reaction b/t aluminum and iron oxide, intended to remove oxygen from oxide and form molten iron
ANSI Z87.1 lens thickness
-most prescription safety Rx: 3.0 mm ct/et -for high plus over +3.00, edge may be reduced to 2.5 mm if it meets impact test -plano prescription safety eyewear no less than 3.0 mm thick or more than 3.8 mm thick
Electric Arc
-most widely used -very high temperature involved -stronger and better weld
ANSI Z87.1 (2010) Frame
-must have "lip" behind lens to prevent lens displacement towards pt -lenses inserted from front -must bear Z87-2 logo (for non plano) -plano lenses in frame (Z87 or Z87.1) -must have A, DBL, and overall temple length ID'd on frame -Z87-2 indicates frame also meets high impact testing (most frames have this today) -meet high mass, low velocity test -meet low mass, high velocity test -meet flammability, corrosion std
qualification for "+" mark
-must pass a high velocity impact test: 1/4" steel ball shot at lens at 150 fps -no detachment, no fracture, no displacement, no penetration
flammability, corrosion test
-per ASTM test method, D635-98 -material burned in 10% NaCl -material shall not burn at a rate greater than 76 mm (3 in) per minute
OSHA requirements of employers
-perform work hazard assessment -equipment selection -proper training (proper personal protective equip-PPE, proper size, intended use)
Types of high impact lenses
-polycarb -Trivex
Hazards in welding
-radiation, smoke, fumes, gaseous by products from iron, nickel, argon, helium, and CO2 -gaseous by products irritant to lungs & eyes -radiation damage (photokeratoconjunctivitis, cataracts, retinal burns) -welder's flash (photokeratitis) -failure to lower helmet timely at arc contact pt -immediate discomfort after flash -stipple staining with NaF
Protective Devices
-safety spectacles -chipping goggles -impact or dust goggles (soft, flexible plastic material, polycarb lenses, wear over glasses) -chemical goggles (similar to impact/dust goggles except different ventilation system) -plastic face shield (protect head, face & eyes from flying debris, chemical or molten metal splash)
Welding lenses- Class II
-specific for reduction of sodium D-line radiance (589.3 nm) -similar to Class I lenses but in addition reduces transmittance at 589 nm with addition of didymium
Welding types
-thermite -gas welding -electric arc
ANSI Z87.1 side shields
-types: permanent, detachable, plastic, wire mesh, plastic mesh -side shields req'd when there is hazard from flying objs -all safety eyewear should have side shield -face shields - clear, tinted (can be worn over dress wear) -goggles/face mask (respirator)
ANSI Z87.1 Radiation
-use of safety eyewear may not be the only source of protection from radiation while welding, cutting, or brazing -can use and should use safety eyewear under appropriate helmet or face-shield -offers protection when shield or helmet is lifted up
Gas welding
-used for metal welding, metal cutting and brazing
Other protection
-welding goggles -dynamic filter devices (may or may not be optimal) photochromic filters liquid crystal filters electro-optic devices mechanically actuated shutters
Shade #
7/3 OD + 1
ANSI Z87.1
lens thickness lens impact lens retention test
Lens markings
non plano basic impact -w2.5 -basic impact lens made by manufacturer "w" with a lens that has a filter with shade number 2.5 non plano high impact -w+2.5 -high impact lens made by manufacturer "w" with a lens that has a filter with shade number 2.5
Purpose of protective eyewear
protect against: -flying particles -molten metal -liquid chemicals -acids or caustic liquids -chemical gases or vapors -injurious light radiation -have proper side protection
