Document dGEXr8DN67BK9dqgZkVQ0QYR
144 Twenty-fifth National Safety Congress
With iheit fondamenult in mind nrt* oos kinds of spring knee leggings were created--one of the first great improve ments in legging construction. However, in some cases there seemed to be justi fied complaints about the circular springs petting too hot for comfort and so the manufacturers promptly eliminated this by covering the springs nr insulating them. Spring knee leggings still are preferred by some and will undoubtedly be used for many years to come.
Bui we find many new so-called springless types of leggings appearing in the field. We also find that the old stunt of wrapping legs in wet burlap is almost ex tinct. thanks to the efforts of safety men.
Subsequently the springiest type of leg ging further combined safety and comfort. The popular appeal oi this type was chiefly its greater comfort and finer ad justability. Every conceivable kind of
fastener is here used to insure case of putting on and to assure quick removal. Entirely new fasteners have l>een devel oped and use has also been made of already existing types.
Individual features carry their appeal to safety men. liet all recognized types of leggings on the market today are much more comfonabk and safe than those of a few year* back.
Leg protection against acid splashes calls for not nearly so many styles of leggings but is adequately covered. The types of leggings and spats that protect against cuts, bruises, and similar injuries are many and varied. Some are made
from a heavy leather base covered with metal reinforcing strips, properly placed to give the needed protection. Others are
made entirely of heavy fibre with or with out metal flares as the hazard demands. Steel studded chrome leather is also osed in some cases. There are styles made from chrome leather reinforced with flexible reeds backed up by felt to act as a shock absorber. A most interesting anti-rattle snake legging is made in a sort of spring knee type, using fibre as a base and cover ing h with water-proofed duck as a fur ther protection while walking through long wet grass.
Pore gram rubber mounted over light leather has been. successfully used at leg and foot protection against sand blast shot. Hip length leggings, while used in lesser numbers, are still standard equip ment hi foundries where protection is needed from the hip down. They range in style from regular pant leg shapes to extensions put on spring knee or springless type leggings and are made from
asbestos doth, fireproofed duck, and leather. A combination of chrome leather bottom with an attachable asbestos top has proved a very desirable style from both a safety and an economical stand point. Here again, as in the knee type, safety, comfort, adjustability, case of put ting on and taking off are important factors. Of course, almost any of these styles of leggings is adaptable for other uses, especially when sparks, molten metal or severe heat are encountered.
In rather rare instances light leggings or spats have been used with more' or less success for teg and foot protection for women.
IYoper protective apparel will speed up production, will keep men on the job. will keep them happy, and will increase profits.
The following questions were brought out in the discussion:
1. Do spats give as good leg protection as leggings?
Xo. 2. Why are spats worn at all?
They are used when workmen have an aversion to leggings or when only low splashes of hot material arc expected. In
the tatter case, however, the workman wearing spats b taking a gamble, bemuse, by the law of average*, the hot splashes may not always be low.
3. What material is the best heat re sister?
Asbestos gives the best protection from severe heat, hot this material will not stand wear and friction as well as some other materials.
Safety Equipment
145
Respiratory Protective Equipment for Use Against Dusts, Fumes and Gases
By PHILIP DRINKER
There appears to be some confusion and one can see large plants for recover
as to the distinction between dusts, ing lead fume--a dry powder. Obvious
fumes, vapors, mists, and gases, with the ly. one does not want the same knuf of
result that respiratory equipment for pro respiratory equipment for two such dif
tection against them occasionally is ferent substances yet the customer often
wrongly applied. The respirator manu asks for a respirator to protect against
facturers hare many examples of soch fumes.
misunderstandings and often are blamed
Lead fume happens to be very difficult
for errors which result solely from eon- to filter out so that the ordinary respir
fusion in nomenclature. Dusts include all types of dry earthy
ator which catches dust particles may lie inadequate against lead fume. The acid
particles small enough to lie blown about fumes, containing both liquid particles
by ordinary air currents. Dust suspen and gas. require a filter to catch the drop
sions may be generated as the result of lets and a gas absorbent to catch the
a grinding, blasting, or comminuting pro gaseous constituent. Therefore. It usu
cess: or they may result from the han dling of finely divided material* as in mixing processes, in sweeping, or the
ally happens that the respirator manufac turer. in self protection, advises the cus tomer to use an air-supplied or air-line
blowing about of wood floor, plant pol respirator because he will then be ade
len*. or common road dust. There is no quately protected whether the fume is of
chemical limitation implied by the term solid particles, like lead, or a liquid and
"dust** while the range in size of dust gas mixture. If the customer stated ex
particles extends from the sob-microscop actly what the suspension consisted of or
ic to small sand grains. Such materials told how it was generated he might be
can be caught very effectively by the able to use less expensive equipment.
modern type of dust respirator.
A vapor is a gas which can be con
Fomea embrace two definite kinds of verted into a liquid at ordinary tempera-
atmospheric suspensions. It is unfortu tores and pressures. Thus, water vapor is
nate that such double-naming exists in a common constituent of the air and is
the trade but one had best admit the fact. contained in concentrations whieh vary
Thus, "lead fume** is a very old term with atmospheric conditions. Respira
used to describe the visible dark grey tory protective equipment is nsed against
suspension which evolves from lead low concentrations of a great many va
heated to high temperatures. The ma pors arising from common organic solv
terial in such suspensions is mostly tiny ents such as benzol. Many such sub
particles of lead (and lead oxide), much stances arc absorbed by activated char
smaller in size than those of the average coal as in gas masks. There is a small
dust, with some lead in the gaseous state. cartridge type respirator in which the
When such a mixture is cooled down to cartridge ii filled with activated charcoal
the point where it can be breathed the for absorbing a vapor such as benzol or
contaminant is then the lead particles with soda-lime for absorbing an acid gas
alone without any gaseous lead.
such as carbon dioxide. Because these
The word "fume** is also used to de scribe the mixture of gas and mist which may come from a bath of Hot nitric acid,
for example. Xone of the material in the suspension is dry--it is all In the form
small cartridges contain comparatively little of the ahsorbant (heir use is lim ited to very low concentrations. They
should not be used for emergency rescue work.
of a true mist (liquid droplets) or as a
A mist consists of a suspension of li
gas. yet it may have a thick brownish col quid droplets together with the gas from
or. One buys fuming sulfuric arid (a which the droplets condensed. The com
liquid) from any chemical supply house monest example b atmospheric fog.