Document 85zLM3pQw4y41qzoVrd2z7dMe
FILE NAME: National Safety Council (NSC) DATE: 1959 Mar DOC#: NSC034 DOCUMENT DESCRIPTION: NSC - National Safety News - Industrial Ventilation
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A N ATIO N AL SAFETY C O U N C IL PUBLICATION
Voi. 79, No. 3
M arch 1959
See also index on page 272
ijTIONAL
f COUNCIL
^ibt> Congress of ihe
pI Kl'fjW States i.fdW/j
sill
3ME office
st
tJ|cn Avenue, C h ica g o I!
`i;: Local Service Office, 60
i, New York 17; Public
||
Chrysler Bldg., New IS
il $i*ei 703 Market St.f San Si* '!& '
1. PLANT DESIGN AND CONSTRUCTION Design for Safety; Floors; Lighting the Plant; Stairs, Ramps, Fixed Ladders ........................................................................................... 15
2. HOUSEKEEPING AND MAINTENANCE Housekeeping, Sanitation; Color; Portable Ladders; Scaffolds . . 25
3. INDUSTRIAL HEALTH ENGINEERING Washrooms and Lockers; Industrial Ventilation; Skin Infections; Solvents; Heat and'Humidity; Drinking Water; Food Service........ 57
4. NOISE CONTROL Engineering and Medical Control; What Type of Noise; Getting Them to Wear Ear Protection; Hearing Aids.................................. 77
5. PERSONAL P R O T E C T IO N -P A R T 1 Eye, Respiratory and Head Protection .......................................... 89
6. PERSONAL PROTECTION-- PART 2 Men's Furnishings; Foot Protection; Protective Clothing; Hands and Arms; Leg Protection; Safety Belts . . . ...................................131
STAFF
panics D. Saul, Robert
ORs: E. L. Alpaugh,
s jjftrry C. Johnson, Arthur % ijfrcn, Harry N. Rosen- fm
IgRobert L, Meyer
NATOr; Jack Horner
|SJA FF
[Jo' sIetsh Sa
SING STAFF
m1
cs
:: Oliver Mickila
1
^Opinions advanced in
i l^^o n al expressions of
III " " `arily those of the
Si f
tejSNEws is published
Council. Copy-
Safety Council M Hncd as second clas i i
*t the Post Ofgce a
I
lhc; act of March 3
g f e S6.50 a year. Singh
subject to 10 pe
>_nof Safety Counci for yeariy sub
r '"!3 0,1 request. Mem ^.Circulation.
were primed. 8M1b
7. MATERIALS HANDLING Analyze Materials Handling; Trucks and Tractors; Hoisting Equip ment; Conveyors; Wire Rope and Slings; Chain and Slings; Fiber
Rope; Aids to Manual H andling.....................................................179
8. MACHINE OPERATION AMD GUARDING Guarding the Machine; Electrical Equipment; T o o ls........'. ......... 195
9. PLANT PROTECTION Fire-Fighting Methods; Portable Extinguishers; Automatic Protec tion; Training Fire Fighters; Flammable Liquids; Static Electricity; Spontaneous Ignition.........................................................................211
10. MEDICAL AND HEALTH SERVICE Medical Service; Care of Injured; Resuscitation .......................... 241
11. SAFETY PROMOTION AND TRAINING Lines of Safety Communication; Signs for Instruction, Direction and Warning; Planning Effective Meetings .....................................257
12. PRODUCT AND SOURCE DIRECTORIES Directory of Safety Equipment Sources; Classified Product Index; Advertisers' Index ......................................................................... 7 275
2 That Vital 15 Per Cent -- Editorial
3 Safety Gains in 1958 4 When the Employee Is a
Customer 5 "Federal Specs"--Uncle Sam's
Shopping Guide 6 Wire from Washington 7 Equipment for Safety Men, Too
(Diary of a Safety Engineer) -- Bill Andrews
1
8 Learning to Live with the Atom
10 Make Plans Before Disaster Strikes
11 Methylene Chloride -- Data Sheet 474
112 Safety Library
173 Consultation Corner ,
268 New Posters
P L A IN T IF F 'S E X H IB IT
0 z% L\
S ectio,i 3-- Industrial Health Engineering
Industrial Ventilation
Providing dean air far the workplace
by the American Standards A ssoli
tion.
3
Where contaminants are to k
removal at their source is necess*^
Ventilation is often complied
by the necessity of maintaining
comfortable temperature. Exha^f
ing impure air is usually practice!*
but in cold weather it may be
cult and expensive to warm ]ai
volumes of incoming air.
^
Natural ventilation is adequate fe
some buildings housing n o n -h a ^
ous operations. Air circulation -,
aided by doors, windows, roof vcsi!
tilators, and monitors. The nuntbci
of outlets should be planned
hot weather when the temperauj
difference inducing the draft isfg
the lowest point.
Jgj car
Air intakes should be locatefffl too
that incoming air is properly
id
pered and does not cause undig - mix
fortable drafts in cold weather. -r'
DUS"/ CONTROL system for removal of asbestos fiber from ore milled in the building. Capacity is 2,500,000' cfm. Area of cloth bags in filter system is about 30 acres, with four miles of ducts and 4,000 dust enclosures, ('Johns-Manville Corp.)
CLEAN AIR is necessary for the health and comfort of those who occupy any enclosed space. For some occupancies, open windows may be adequate. For others elabor ate 'exhaust systems may be needed to remove contaminants from the workroom air. Ventilation also in cludes control of heat and humidity.
Maintaining air hygiene require ments may be complicated by the generation of toxic or nuisance air contaminants in industrial proc essed
Air pollution has become a prob lem for whole areas as well as for individual plants. In some regions, particularly those which are built up and where the topography does not permit the quick dissipation of contaminated air, gases, dusts, and combustion by-products must be treated to make them safe and un objectionable before venting to the outside.
Natural ventilation-- air circula tion through openings in walls un assisted by mechanical equipment -- i: satisfactory only when the building layout permits .free circulatic n of air and where plant proc
esses do not generate objectionable air contaminants.
Principles of ventilation. Ven tilating systems are based on either of two general principles, or a com bination of the two:
1. Plenum ventilation. Air is driven into the room by fans, dilut ing the room air with fresh air, forcing out stale air through doors, windows, and cracks. This method is limited to buildings where con taminants are non-toxic and limited in quantity.
2. Exhaust (vacuum) systems. Air is drawn from a room by fans and is replaced by air entering through doors, windows, and other openings.
General Ventilation
Where processes are not injurious to health, general ventilation is usu ally satisfactory. It is also satisfac tory where dilution of air contami nants will keep the concentration below permissible limits for continu ous exposure. Standards for many contaminants have been compiled
Artificial general ventilation l$i=t hu; quires properly located inlets a i 1 (V'L outlets. Air coming into the roots' must be uncontaminated and dis cahvaoridge repcoiirnctuslasthioonu.ld be located io Lo
Contaminant heavier than nil* can be removed most effectively through openings at floor level, do
Fans and blowers. Both portal and stationary types are usefulA increasing circulation of air affords relief from heat. 1 not substitutes for exhaust vei| tion where air contaminants mf be removed.
For moving large volumes o S blowing is more efficient th a n | tion.
Devices for air circulation | | come less effective as tempera| and humidity rise.
Caution should be used in | movement, particularly with vei| ties over 200 fpm. When relati| cool air is blown over workers# high velocity, objectionable dr are created.
Control Measures
Where there is a definite so'
of air contamination, general vet
lation alone is seldom sufficig
Control involves three steps; %
1. Identifying the substance B
locating its source.
iL
It
Nat ion al Safety News, March, l|j
S e c tio n 5--'/ffc/iisfr/ir/ Health E n g in e e rin g
j p | eric sampling to denature and extent of
create a sufficient movement of air to withdraw contaminants at point
pletely as possible. Air. velocity de creases approximately with the
lamination. T w iner control measures. J ,: tie source may in-
or more Of these meas-
of origin and convey them to a safe point for disposal.
An exhaust system consists of four major parts:
square of the distance from the
hood opening. Air velocity for effective control
varies with the process and mate
htior or enclosure of the ardo'is operation. a j exhaust ventilation,
1. Hoods or enclosures near source of contaminant.
2. Piping to connect hoods into system.
rial exhausted. Generally speaking, the better the enclosure and design of the hood, the lower the velocity needed.
raiit nal changes; substitu-
3. Collection equipment.
Hoods or enclosures may be in
, 0f irocess or materials.
4. Fan.
the form of booths, canopies, lateral
idS
hoods, downdrafts through grill
jon (onnes the operation
Dust is usually more difficult to openings below the process, or slot-
tefinife location. Exposure is control than gases, vapors, mists, type hoods. The object is to remove
eliminated or restricted to a and fumes. Dusty operations tend the contaminants without drawing
- ted, trained, and equipped to project particles so that the hood it through the breathing zone of the
must provide velocities sufficient to operators and with minimum inter
p tio i which combine ex Entilahort with isolation and !tf i tclude: sandblasting ffiak out and tumbling-bar ISratio ns in foundries, dry fpmd mixing of volatile liq-
draw them into the exhaust system. Exhaust hoods should enclose the
process as completely as possible or the hood should be located to take advantage of the directional effects of the dust flow.
Dust-removal systems generally
ference with processing. Hoods can be made more efficient
by addition of flanges.
Ducts connect the hoods to the central fan, distribute the air flow in direct proportion to the require
c.reating excessive heat, noise should also be
ever possible.
require higher air velocities and ducts of heavier gauge metal than those designed for gases.
Each part has its independent
ments of each inlet, and maintain adequate pipe velocity to convey the contaminant to the point of dis charge.
function but ail must be designed to
-- To page 73
Exh aust Systems
ex must systems are an nt means of occupational'
work together efficiently.
The exhaust hood is the most important part of the system. It
References--Veirtilaiion, Dust Control
?control. Their purpose is to should enclose the process as com- National Safety Council
i s iff.SB
Accident Prevention Manual for Indus trial Operations, 1955.
Local Exhaust Systems, Checking Per formance of; Data Sheet D-428.
Vapor Degreasers; Data Sheet D-429. Exhaust Ventilation Systems, Instruments for Testing; Data Sheet D-431.
National Safety News
Conditions U nder' Control; Aug. 1951. . Practical Aspects of Dust Suppression; Part I, Feb. 1953; Part II, May 1953.
Heat, Hazard and Humidity; May 1953. Protection Against Radiant Heat; A. M. Wallach, June 1953. Public Health Is Their Responsibility; July 1954.
Recovers Coal, Removes Fly Ash; Apr. 1955.
Out Goes the Bad Air; Oct. 1955.
iS -? labil
American Society of Heating and Air Conditioning Engineers
Heating, Ventilating and Air Condition'ing Guide, 1956.
American Standards Assn.
Light and Ventilation, Building Code Re quirements for, A53.1-1946.
Toxic Dusts and Gases, Allowable Con centrations for, Z37 Series.
Blower and Exhaust Systems for Dust, Stock and Vapor Removal, Regulations for Installation of, Z33.1-1950.
ITION! under control. Heating, ventilating, and air-conditioning in the Reynolds
^ C o m p a n y 's office building, Richmond, Va., is regulated from this central control .../-(Mirnie ipolis-Honeywell.)
Books
Industrial Health Engineering; Allen D. Brandt, John Wiley & Sons, 1947.
The Industrial Environment and Its Con trol; J. M. Dalla Valle, Pittman Publish ing Co., 1948.
M ar
H?0/ Satisfy News, March, 1959
7
S ectio n 3-- In d u striai Health Engin e erin g
and hangers on elevat-
i_ 5 are used instead of locfc-
scmc industries, such as
^ Bnd foundries. Damp work
-
b; dried between shifts
V,, . : n 0 ian be hastened by
^ S l T a t the ceiling. This ar-
^nt conserves floor space.
Roam
`fitst roor i should be provided 10 or :nore women are emWhe e there are fewer I `and a separate room is not
ble, sui able space may be I off.
.10 wo nen, minimum space ' fq* ft- 'vith at least 2 sq. ft.
-h ad iitional woman em-
dfless than 100 women, at bed or couch should be
ci. For 100 to 200 workers, ,,8, and . bed for each addi'%250 werkers. * * *
intilaticin
jam page 61
The system should be balanced so ~leach hood draws the proper
uht of air When this condition ucen obta. ned, all means of adent shotld be permanently
Areas sf branch pipes and Tducts can be calculated to give
t air velocities throughout the
(Serial us 3d for ducts must reIprasive action of dust or cor."effects of gases and vapors,
turns in ducts take extra 1and cause a large pressure
snPPs wSh slean-out gates should 'Provide.: a: the bottom of vertijifuns, and clean-out gates at
lar intervals on the bottom side horizontal runs.
shou d have a capacity r,-% higbe.' than calculated re
gents to allow for leakage in . astern, accumulation of mate. , 0:1 fan blades, and similar diifi#ies. in h e re the contaminant is hot ^as a na'ural tendency to rise g 1the open lion can be provided
an effective enclosure type natural draft ventilation is 33 satisfactory.
SofeSy News, March, 1959
Portable ventilators are used for supplying fresh air to confined spaces for temporary work. Ex amples are tanks, tank cars, vats, underground cable manholes, pipe galleries, ship holds, and airplane wing compartments and fuselages.
Where objectionable fumes are produced, as in welding under some conditions, ventilators exhaust con taminated air.
Disposal of Contaminants
Equally as important as collect ing the air contaminants is its dis
posal. Gases, vapors, and mists, may often be discharged to the out side atmosphere at a point where they will not recirculate around the premises in harmful concentrations.
Dusts, both harmful and nui sance, require the use of dust col lectors in the system.
Recirculation of air is generally undesirable, particularly when the air has contained gas or fumes. Where only nuisance dusts are in volved, recirculation after cleaning is often permissible.
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1443 FOURTHI'STREHET./(Slnc'lo 19l09)-iUERKEI.EY:,:.IQfCALIFORNIA'
C irc le Item N o. 47---Read er Service C a r d
73
Section 3-- Industrial Health Engineering
Leading industrial doctors advise immedic:e washing with plenty of running water as ti .R -best first aid treatment for any chemical h. the eyes. Records prove that washing with v citer for ten minutes or more, close to the crcident, is necessary to reduce or eliminate eve damage.
Forehead operation leaves hands free to c sen eyelids so water can be directed where rsr chemicals might be lodged. Sanitary white triced enamel bowl is resistant to most fumes,
Over 500 industrial plant installations have Ireen made to date.
W rits For Details,
VALVE N E W
Chain Operated B M B R G S N C Y
Q rick Action eli-Closing
SJfO W SF L
The B & A Shower is the quickest and most satisfac tory way to saturate a work er with gallons of water the Jnstcrt an accident occurs, to prevent a dis figuring bum--even a fatality.
Sf ecial shower head, no holes to clog--can be used where unfiltered water prevails.
Write For Details.
Recirculation is not desirable when handling dusts containing such substances as lead, silica, and asbestos.
Air coming from the cleaning device must fall within the permis sible range for toxic or flammable dusts.
Dust Collectors
Methods of removing dust from the air exhausted by the system in clude:
1. Filtration. 2. Electrostatic precipitation. 3. Wet collectors. 4. Dynamic precipitation. 5. Supersonic flocculation.
F ilters are porous mediums through which dust-laden air is drawn. Some are designed to collect dust in the form of a layer on the upstream surface. This is character istic of cloth and paper filters. Thicker types, such as those of metal mesh or glass fiber treated with oil, have greater dust-holding capacity but do not collect the finer particles.
A filter should have:
1. Low initial resistance to air flow. 2. Reasonable length of service. 3. Efficiency under changes of tem
perature and humidity. 4. Low flammability. 5. Reasonable replacement cost or
ease of cleaning. 6. Low maintenance cost. 7. Freedom from odors.
Cyclones. A cyclone consist, an outer cylinder fitted with an! verted cone-shaped hopper and! inner concentric cylinder ^ serves as a discharge duct. Air fi the main duct of the exhaust ,, tem, under high velocity, enters large chamber where the air is a circular motion. The heavier '' tides are thrown to the outer by centrifugal force and fall a]i the wall. Air escapes through top.
Cyclones are the most effec for large particles, such as sawdf, shavings, or heavy lint. After pag ing through them, air cannotlf returned to the workroom witM further filtering. Cyclones are f f !' tively inefficient for removing s particles.
Multiple small diameter cycle of small taper collect finer parTM than the common large dian,_, ones, mostly because of highelif locities and greater, centrifug force.
Dynamic separators combine' and collector in one unit. This; of separator is somewhat lik cyclone, but the centrifugal s
HIGH VOLUME
Electrostatic precipitation is high
C IS P IG U R IN G
I I'A C IA L C U T S ,
/-HD B U R N S '
ly efficient--particularly for fine dusts which are difficult to remove
by other methods. It offers low re
l^ lo o V
NEW
% LOBW&CAOST
SAF-T-BAGS
5 PINT 1 GALLON 5 GALLON
are widely used for the safe handling of glass bottles' con taining harmful chemicals; also the storage' and recovery of expensive serums, biologicals, and other costly products.
Painful cuts, disfiguring bums, loss of eyesight, or even tx fatality, do result from corro sive liquid splash and flying glass when unprotected bottles shatter.
Write For Details.
A SSO C IA T E SJN C
sistance to air flow. First cost and maintenance cost are relatively high.
Portable units are helpful in re moving dust and smoke from small rooms.
Precipitators are less effective in collecting large particles moving with considerable force. For high concentrations of dust they gener ally require pre-cleaners. They are valuable when the process requires a practically dust-free atmosphere.
A combination of viscous filter and electrostatic precipitation with a self-cleaning feature is used on some models. It solves the problem of dust capacity and of heavy par
. . . accurately samples the ai
air pollutants, including radipc particulate matter, dusts, smoke;^
. . . detects and measures cor and industrial health hazards.
. . . designed for indoor or ou; testing-- accurately samples par late matter as small as 1/1 00^
micron.
^
. . . inhales an entire area.
. . . portable . . . plugs in any|j V, A.C. outlet.
. . . indispensable for series 1
testing.
Write far information to:
The
A ir Sampler Division 777 Fifth Avenue, Pept-
Brooklyn 32, N. Y.
P.
Box 7542, Dept. N.S., C hicago &, III.
Lircla [tarn No. 48-- Re ad e r Service C a r d
ticles.
Circle Item No. 49-- Read er Service
74
National Safety News
ion is performed by the blades. It is more efficient
fS&e cvclcne.
. .
fejm e types water spray is m-
*' w|th the dust at the inlet,
f le c tio n increases efficiency
jjjjjlK dusts.
M callectnrs use several devices g ^ jin in g contact of water with ^ ^ to u s te d air so that dust partij jQim a s.udge. One type con-
' pf spra/s or water curtains ih which dust-laden air is "" Si These are efficient collectors
pwujy types of dust. t imports nt application is in the ntion of dust explosions from Bg aluminum or magnesium.
personic flocculation. Suspend, is passed through a field of pnic vbrations, inaudible to
plan e a g e n e ra te d by a highliency siren. Vibration floccu"|the fins particles, and the Sjates are then collected by f e s or other measures for coltlhc relath ely coarse particles.
Personal protective equipment is needed where exposure is occasional or where complete protection is not practicable. Removal of the hazard at its source should remain the objective.
Section 3--'fndtfifrfai Heoftft Engineering
Sanitation and maintenance must receive constant attention to keep equipment at top effectiveness and prevent development of unhygienic conditions.
Supervision and training of em ployees, particularly in hazardous operations, are important.
Medical control is an important check on other methods. Engineer ing control is sometimes inadequate and symptoms of absorption of toxic materials by a worker may be the first real warning.
The safety department should be notified of the introduction of new materials and processes so possible hazards may be assessed and safe guards provided.
Workers exposed to toxic sub stances should have frequent physi cal examinations. * * *
plus
vitamins Bi B2 and C
In hot weather, most people eat less-thus fail to meet the body's m inim um vitamin needs, or to replace all salt lost by the system.
N ow -"Pep-U ps" with BOTH vital elements help your workers main tain full physical efficiency. Hold down the Hot W eather Rise in Accident Rates, with
Wiping Up Grease
with VITAMINS ADDED
Removing oil and grease from machine tools and dies and other wiping jobs may be done by paper wipers, industrial wiping towels, and waste or salvaged rags.
Either of the first two methods is more likely to promote good house
Each salt crystal Individually cooted for slow, controlled dis solving - W / ll N O T C A U S E
"S A IT SICKNESS"
in Cortven/on/ All-Weather Sanitary, Expendable DISPENSERS of Attractive, Durable Styrono Plastic
at ho extra cost
keeping. Paper wipers are collected
and burned at the end of the day, reducing the fire hazard. Convenient receptacles are needed. The paper is highly absorbent and has enough wet strength for use with solvents.
Wiping towels of sturdy cotton cloth are absorbent and offer some protection to the hands where work is done around metal chips and turnings or on rough surfaces. Cloth towels are furnished by industrial laundries.
Special Introductory Offer
20% DISCOUNT
an all order! far "Pop-Up* with Vitamins" received before April 15.
1000-Tablet Dlipenser, Cat. No, 1424. SDO-Tablnt Dis penser, No. 1414. 1500-Tabici Bulk Carton, No. 1431.
Early Order Discount 3% D I S C O U N T
on all orders for "Pep'Upi Impregnated without Vitamins" received bofore April 15.
lOOO-Toblef Diipanvr, Cat. No, 1124. 5 0 0 -T a b k i Di*poruar. No. 11)4, 5.500-Tobjel Bulk Carton, No. 1131. Alio available--.Enteric Cooled "P op-U p t", object to same 5 % Early Qrdnr Dttcounl.
With salvaged rags and waste,
men sometimes keep partly used
rags behind benches, in corners and
under machines, creating a house
. ; 1 .{
keeping problem and a fire hazard.
Safe metal containers should be
provided and their use required.
item Nh. 50--Ruador Servici Card S a fe / Wows, March, 1959
Cleanliness around steam pipes
Girds Ifem No. 51-- Reader Sarvtco Caret 7S