Ventilation

Dust hazards created by abrasive blasting v How respirable dust is formed v Composition and toxicity v Review exposure limits in 29 CFR a

Dust hazards created by abrasive blasting v Organic abrasives v Flammable or explosive dust 1b

Blast-cleaning enclosures v Exhaust ventilation v Baffling air inlets and access openings v Rate of exhaust 2a

Blast-cleaning enclosures v Before opening: blast must be turned offblast must be turned off exhaust system must be runexhaust system must be run v Protection for observation windows v Slit abrasive-resistant baffles 2b

Blast-cleaning enclosures v Doors must be flanged and tight when closedmust be flanged and tight when closed must be operable from both inside and outsidemust be operable from both inside and outside 2c

Inspection & maintenance of exhaust systems v Z , and ANSI Z v Dust leaks must be repaired ASAP v Static pressure drop at the exhaust ducts 3a

Inspection & maintenance of exhaust systems v Installations where the abrasive is recirculated v Dust collectors 3b

Personal Protective Equipment v Abrasive-blasting respirators must be worn: inside blast cleaning roomsinside blast cleaning rooms when using silica sandwhen using silica sand when toxic dust exceeds exposure limitswhen toxic dust exceeds exposure limits v Dust filter respirators 4a

Personal Protective Equipment v Heavy canvas or leather gloves and aprons v Safety shoes v Eye and face protection 4b

Air quality for abrasive- blasting respirators v Free of harmful quantities of dusts, mists, or noxious gases v Meets requirements in 29 CFR (i) 5a

Operating procedures and general safety v v Dust must not accumulate on the floor or ledges outside of an abrasive-blasting enclosure v v Dust spills must be cleaned up promptly v v Keep aisles and walkways clear 6a

Grinding, polishing, and buffing operations v Local exhaust ventilation systems Remove dust, dirt, fumes, and gasesRemove dust, dirt, fumes, and gases Required when employee exposure exceeds permissible exposure limitsRequired when employee exposure exceeds permissible exposure limits 7a

Grinding, polishing, and buffing operations v Hood and branch pipe requirements Design and placement so particles fall or are projected into the hoodsDesign and placement so particles fall or are projected into the hoods Operation must not cause particles to be thrown into the operators breathing zoneOperation must not cause particles to be thrown into the operators breathing zone Follow specified exhaust volumesFollow specified exhaust volumes 8a

Grinding, polishing, and buffing operations v Exhaust system requirements Designed and tested in accordance with American Standard Fundamentals Governing the Design and Operation of Local Exhaust Systems, Z Designed and tested in accordance with American Standard Fundamentals Governing the Design and Operation of Local Exhaust Systems, Z All exhaust systems must be provided with suitable dust collectorsAll exhaust systems must be provided with suitable dust collectors 9a

Hood and enclosure design v Functions to: Protect the operator from the hazards of bursting wheels, andProtect the operator from the hazards of bursting wheels, and Provide a means for the removal of dust and dirt generatedProvide a means for the removal of dust and dirt generated v Structural strength 10a

Hood and enclosure design v Adaptable to particular machine v Exhaust hoods for floor stands, pedestals, and bench grinders must be designed in accordance with figure G-2 of (b) 10b

Hood and enclosure design v Swing-frame grinders must be provided with exhaust booths as indicated in figure G-3 of (b) 10c

Hood and enclosure design v Portable grinding operations, whenever the nature of the work permits, must be conducted within a partial enclosure 10d

Hood and enclosure design v Hoods for polishing and buffing and scratch-brush wheels must be constructed to conform as closely to figure G-4 of (b) as the nature of the work will permit 10e

Hood and enclosure design v Cradle grinding and polishing operations must be performed within a partial enclosure similar to figure G-5 of (b) 10f

Hood and enclosure design v Hoods for horizontal single- spindle disc grinders must be constructed to conform as closely as possible to the hood shown in figure G-6 of (b) 10g

Hood and enclosure design v Horizontal double-spindle disc grinders must have a hood encircling the wheels and grinding chamber similar to that illustrated in figure G-7 of (b) 10h

Hood and enclosure design v Vertical-spindle disc grinders must be encircled with a hood so constructed that the heavy dust is drawn off a surface of the disc the heavy dust is drawn off a surface of the disc the lighter dust exhausted through a continuous slot at the top of the hood as shown in figure G-1 of (b)the lighter dust exhausted through a continuous slot at the top of the hood as shown in figure G-1 of (b) 10i

Hood and enclosure design v Grinding and polishing belt hoods must be constructed as close to the operation as possiblemust be constructed as close to the operation as possible the hood should extend almost to the beltthe hood should extend almost to the belt one-inch wide openings are provided on either sideone-inch wide openings are provided on either side 10j

Operations considered to be spray finishing v Methods wherein organic or inorganic materials are utilized in dispersed form for deposit on surfaces to be coated, treated, or cleaned v May involve either automatic, manual, or electrostatic deposition 11a

Operations considered to be spray finishing v Does not include: metal spraying or metallizingmetal spraying or metallizing dippingdipping flow coatingflow coating roller coatingroller coating tumblingtumbling centrifugingcentrifuging spray washing and degreasing systemsspray washing and degreasing systems 11b

Location and use of spray booths v Enclose or confine all operations 12a

v Must be located as provided in sections 201 through 206 of the Standard for Spray Finishing Using Flammable and Combustible Materials, NFPA No Location and use of spray booths 12b

Location and use of spray booths v Used to enclose or confine all spray finishing operations covered by 29 CFR v Terms Spray boothSpray booth Spray roomSpray room 12c

Design and construction of spray booths v 29 CFR (b)(1)-(4) and (6)-(10) v ANSI Z a

Design and construction of spray booths v Lights, motors, electrical equipment, and other sources of ignition must conform to the requirements of 29 CFR (b)(10) and (c) v In no case must combustible material be used in the construction 13b

Design and construction of spray booths v Walkways v Baffles, distribution plates and dry-type overspray collectors v Wet or water wash spray booths 13c

Design and construction of spray booths v Collecting tanks v Pump manifolds, risers, and headers 13d

Design and construction of spray rooms v Must be constructed of masonry, concrete, or other noncombustible material v Must have noncombustible fire doors and shutters 13e

Design and construction of spray rooms v Adequate ventilation the atmosphere in the breathing zone of the operator must be maintained in accordance with the requirements of 29 CFR (c)(6)(ii)the atmosphere in the breathing zone of the operator must be maintained in accordance with the requirements of 29 CFR (c)(6)(ii) 13f

Design and construction of spray rooms v Spray rooms used for production spray-finishing operations must conform to the requirements for spray booths 13g

Ventilation during spray finishing operations v Ventilation must be provided in accordance with provisions of 29 CFR (d) 14a

Ventilation during spray finishing operations v Where a fan plenum is used it must be of sufficient strength or rigidity to withstand the differential air pressure or other superficially imposed loads for which the equipment is designed and also to facilitate cleaning - 29 CFR (c)(5)(iii) 14b

Ventilation during spray finishing operations v Inlet ductwork v Exhaust ductwork 14c

Velocity and air flow requirements v Except where a spray booth has an adequate air replacement system, the velocity of air into all openings of a spray booth must be not less than that specified in Table G-10 of 29 CFR (c) for the operating conditions specified 15a

Velocity and air flow requirements v Adequate air replacement system v Total air volume 15b

Velocity and air flow requirements v Respirator is required when the operator is downstream from the object being sprayed v Downdraft booth doors must be closed when spray painting 15c

Make-up air in spray finishing operations v Clean fresh air must be supplied to a spray booth or room in quantities equal to the volume of air exhausted through the spray booth 16a

Make-up air in spray finishing operations v Self-closing doors, dampers, or louvers v Filtered air supply v Heating make-up air 16b