cleaned before the commencement of each shift or in an interval
during each shift. No person except those engaged in cleaning
shall be present during the operation. If cleaning is effected
by sweeping, the occupier shall require the persons doing it to
wear the respirators provided or other protection for the mouth
and nose.
12. The occupier shall not permit the workers to bring spirits
into the factory.
13. A lavatory and cloakroom and, separated from them and in
a part of the building free from dust, a meal room shall be
provided. These rooms shall be kept clean, free from dust, and
be heated during the winter.
In the lavatory and cloakroom water, soap, and towels shall be
provided and adequate arrangements shall be made for keeping
the clothing taken off before commencing work.
The occupier shall give the persons employed opportunity to
take a warm bath daily before leaving work in a bathroom
erected inside the factory and heated during the winter.
14. No woman or male young person under eighteen years of age
shall work or remain in a room into which basic slag is brought.
Persons under eighteen years of age shall not be employed in
beating sacks which have contained basic slag.
15. No person employed in breaking or grinding, emptying,
packing, or storing basic slag, shall work more than ten hours
daily.
There shall be intervals during working hours amounting in the
aggregate to two hours, one of them lasting at least an hour.
If duration of employment daily is limited to seven hours with
never longer than four hours’ work without an interval, only
one interval of at least one hour is required.
16. For work mentioned in Para. 15 no person shall be employed
without a certificate from an approved surgeon stating that he
is free of disease of the lungs and not alcoholic. The occupier
shall place the supervision of the health of the workers under
a surgeon who shall examine them at least once a month for
signs of disease of the respiratory organs and alcoholism.
Workers engaged in the operations mentioned in Para. 15 shall
be suspended from employment when the surgeon suspects such
illness or alcoholism. Those showing marked susceptibility to
the effect of basic slag dust shall be permanently suspended.
17. A health Register shall be kept in which shall be entered
the precise employment, duration of work, and state of health
of the persons employed.
18. The occupier shall obtain a guarantee from the workers that
no alcohol or food shall be taken into the workrooms.
Preparation of Hydrofluoric Acid
(See also pp. 37 and 171)
The fumes given off in the preparation of hydrofluoric acid require to be
collected in leaden coolers and vessels; that which escapes requires to
be absorbed by a water spray in towers. The apparatus must be impervious
and kept under a slight negative pressure.
Chromium Compounds
(See also pp. 55-8 and 185)
The German Imperial Decree, dated May 16, 1907, contains the preventive
measures necessary in bichromate factories. According to this, workers
suffering from ulceration of the skin (chrome holes, eczema) are not to
be employed except on a medical certificate that they are free from such
affections, and daily examination for signs of ulceration is enjoined,
so that those affected may receive prompt treatment. Further, periodical
medical examination of the workers is required at monthly intervals.
Respirators (for work in which dust cannot be avoided), with lavatory,
cloakroom, and meal room accommodation, are to be provided, and also
baths. In handling bichromates wearing of impervious gloves may be
necessary, and smearing the hands and face with vaseline is recommended.
In addition diffusion of dust and fumes must be minimised; machines
in which mixing, crushing, and grinding are done must be impervious,
and provided with exhaust ventilation. Charging of the furnaces, where
possible, should be effected mechanically and the fumes developed both in
manipulation of the furnaces and from hot bichromate liquor removed by an
exhaust.
A leaflet containing directions for workers coming into contact with
chromium compounds in chemical factories, dyeing, tanning, wood staining,
calico printing, wall paper printing, painting, &c., has been drawn up by
Lewin. It contains a list of the poisonous chrome compounds and of the
industries in which chrome poisoning occurs, information as to the action
of chrome upon the skin and mucous membrane, and the preventive measures
necessary. Among the last named are: smearing the skin with oil, use of
impervious gloves, respirators in work where dust arises, necessity of
cleanliness, and periodical medical examination.
For the _chrome tanning industry_ the following leaflet was drawn up
by the Imperial Health Office in Berlin, which succinctly states the
measures against chrome poisoning in these industries and contains much
practical information for the workers:
In chrome tanning by the two bath process, the first bath
containing potassium bichromate and hydrochloric acid has a
corroding effect upon broken surfaces of the skin (scratches,
chapped hands, eruptions, &c.). In consequence, they develop
into round ulcers (chrome holes) with hard raised edges which
are difficult to heal and go on increasing in size unless work
at the process is temporarily given up. In persons with very
sensitive skin, even though the surface may be intact, handling
the liquor brings on sometimes an obstinate rash (eczema) on
the hands and forearms.
The solution used in the one bath process has no corrosive
action, but it is a strong poison, just as is the solution of
potassium bichromate of the two bath process. If swallowed, the
solutions cause vomiting, diarrhœa, kidney trouble, and even
death. Chromium compounds can also enter the body through skin
wounds and cause illness.
_Prevention._—In order to prevent the occurrence of chrome
ulceration, workers employed with chrome or chrome solutions
must be especially careful in avoiding injury to the skin of
the hands or forearms. This applies especially to workers who
carry the vessels containing bichromate, who weigh and dissolve
the potassium bichromate, or who come into contact with the
tanning liquor or with undressed skins and hides which have
lain in the liquor.
If, in spite of precautions, eruptions, rashes, or ulceration
occur, all work necessitating contact with corrosive tanning
liquors should be suspended until they are healed.
In order to reduce risk of action of the liquor on the skin,
workers employed in the process described would do well if,
before commencing work, they carefully smeared hands and
forearms with unsalted lard, vaseline, or the like, and during
work avoided, as much as possible, soiling the bare hands and
arms with the liquor.
If, nevertheless, a worker has contracted a chrome hole, or
eruption, he should consult a medical man, informing him at the
same time of the nature of his work.
To avoid internal absorption of chrome, workers preparing the
baths must carefully avoid inhaling the dust of chromium salts.
These and all other workers engaged with the liquors containing
chromium must not take food and drink while at work. Working
suits should be taken off and face and hands washed with soap
before eating or drinking, and before leaving the factory.
Petroleum, Benzine
(See also pp. 59-64 and 222-4)
As crude petroleum and the higher fractions first distilled from it
affect the skin injuriously, wetting the skin should be avoided, and
careful cleanliness on the part of the workers enjoined. Workers exposed
to the influence of gases escaping from naphtha springs and wells should
be equipped with breathing apparatus (smoke helmets); this applies to
those who have to enter stills and other apparatus connected with the
distillation of petroleum.
In the preparation of petroleum by sulphuric acid sulphur dioxide in
great quantity is developed, constituting a distinct danger to the
workers. This process, therefore, should be carried on in closed vessels
furnished with mechanical stirrers or compressed air agitators. The most
suitable apparatus is that illustrated in fig. 13.
Petroleum tanks must be thoroughly aired before they are cleaned and
should be entered only by workers equipped with breathing apparatus.
Apparatus containing petroleum and benzine requires, as far as possible,
to be closed in and air tight (as, for example, in the extraction of fat
from bones and oil seed, in the rubber industry, and in chemical cleaning
establishments); where benzine fumes develop they should be immediately
drawn away by suitably applied exhaust ventilation. This is necessary, on
account of the danger of fire, in chemical cleaning establishments where
purification is effected by means of benzine in closed drums.
Regulations for benzine extraction plants are contained in the Prussian
Ministerial Decree, dated January 5, 1909, for benzine extraction
works, and also in that of August 3, 1903, for dry-cleaning premises,
to which last were added ‘Directions for safety,’ containing important
regulations as to risk from fire. From our standpoint the following
points are of interest: care is to be taken to provide and maintain
exhaust ventilation directly across the floor. The air, however, must
not be allowed to pass near any fire. Drying rooms especially are to be
lofty and airy, and separated from other workrooms. In factories with
mechanical power the authorities may require provision of artificial
ventilation for the drying rooms. Washing machines, centrifugalising
machines, and benzine rinsing vessels should be furnished with
well-fitting covers to be removed only for such time as is absolutely
necessary for putting in and taking out the articles to be cleaned,
shaken, or rinsed. The vessels named are to be examined as to their
imperviousness at least once every quarter by a properly qualified
person. The condition in which they are found is to be noted in a book to
be shown to the Factory Inspector and police authorities on demand.
Lastly, substitution for benzine of other less poisonous substances such
as carbon tetrachloride has been urged.
Phosphorus, Lucifer Matches
(See also pp. 49-53 and 190)
In view of the danger of the lucifer match industry, measures were
taken at an early date in almost all civilised states to guard against
phosphorus poisoning, and in many countries have led to the prohibition
of the use of white phosphorus. Complete prohibition of its manufacture
and use was first enacted in Finland (1872) and in Denmark (1874).
Prohibition was decreed in Switzerland in 1879 (in January 1882 this was
revoked, but again enacted in 1893), and in the Netherlands in 1901. In
Germany the law prohibiting the use of white phosphorus came into force
in January 1908, and runs as follows:
1. White or yellow phosphorus shall not be employed in the
production of matches and other lighting substances. Lighting
substances made with white phosphorus shall not be kept for
sale, or sold, or otherwise brought on the market. Provided
that this shall not apply to ignition strips which serve for
the lighting of safety lamps.
2. Persons wilfully infringing this law shall be punished
by a fine of 2000 marks. If the infringement occurs through
ignorance the fine shall consist of 150 marks.
In addition to the fine, all prohibited articles produced,
imported, or brought into the trade shall be confiscated,
as well as the implements used in their production, without
reference to whether they belong to the person convicted or
not. If prosecution or conviction of the guilty party cannot be
brought home, confiscation nevertheless is to be carried out
independently.
Roumania and France have a state monopoly of matches; in these states
no white phosphorus matches have been produced since 1900 and 1898
respectively. France, by the Law of December 17, 1908, signified
concurrence with the International Convention in regard to the
prohibition of the use of white phosphorus.
In Sweden and Norway the prohibition of white phosphorus is in force
only for the home trade. A Swedish Decree, dated December 9, 1896,
permitted factories carrying on the manufacture for export to use white
phosphorus, and almost precisely similar provisions are contained in the
Norwegian Decree. The Swedish Decree, dated March 30, 1900, permits white
phosphorus matches to be exported, but not to be sold in the country. In
Austria difficulties in regard to prohibition of white phosphorus arose
owing to trade conditions (especially in the East), and the attitude of
the states competing in the lucifer match trade, particularly Italy and
Japan. Austria, therefore, made agreement with international prohibition
of white phosphorus, dependent on the attitude of Japan; since Japan did
not concur, the decision of Austria fell through. When, however, Italy in
the year 1906 joined the Convention, the difficulties were also overcome
in Austria, and by a law similar to that of Germany, dated July 13, 1909,
prohibition of the manufacture and sale of white phosphorus matches dates
from the year 1912.[H]
Belgium has refrained from prohibition of white phosphorus, but on the
other hand has passed a series of enactments relating to the match
manufacture, of which the most essential are here cited, since they
characterise the measures which come into consideration for factories in
which white phosphorus is still employed.
_Royal Decree, dated March 25, 1890, modified by the Royal
Decree, dated February 12, 1895, and November 17, 1902,
concerning employment in lucifer match factories._
1. In match factories where white phosphorus is used, mixing
the paste and drying the dipped matches shall be carried on in
a place specially set apart for the purpose.
2. Mixing the paste shall be carried on in an entirely closed
vessel or in one connected with an efficient exhaust draught
locally applied.
The proportion of white phosphorus in the paste shall not
exceed in weight 8 per cent. of the total material, not
including water.
3. Hoods and ducts communicating with an exhaust draught shall
be installed at the level of the plates for dipping white
phosphorus matches, and over the vessels containing the paste.
4. Drying rooms for white phosphorus matches, if entered by the
workers, shall be mechanically ventilated.
5. Rooms in which phosphorus fumes can arise shall be lofty and
well ventilated, preferably by an exhaust at the level of the
work benches, communicating with the main chimney stack.
The workrooms shall be kept clean. No food or drink shall be
taken in them.
6. In every match factory the workers shall have at their
disposal a special cloak room and suitable and sufficient
washing accommodation, so as to be able to change clothes
before commencing, and at the end of, work, and to wash the
hands and face on leaving.
Cleanliness will be obligatory upon the workers manipulating
phosphorus paste or matches.
7. Workers coming into contact with phosphorus paste or matches
shall be examined monthly by a surgeon appointed by the
Minister of Industry, who shall be paid by the occupier.
Workers having decayed, unstopped teeth, or exhibiting symptoms
of gingivitis or stomatitis, or in poor health at the time of
examination, shall be temporarily suspended from work.
The surgeon shall enter the results of his monthly examinations
in a prescribed register.
This register shall be shown to the Factory Inspector on demand.
These decrees are supplemented by further orders regarding the taking of
samples of paste in match factories and store houses (Royal Orders of
March 25, 1890; February 12, 1895; April 18, 1898; November 17, 1902).
As is evident from the Belgian enactment, in states where prohibition of
white phosphorus is not in force, palliative measures only are possible
and even then they can only be enforced in large factories when automatic
machinery is used to eliminate hand labour in dangerous operations. In
this respect the introduction of closed, ventilated, mechanical mixing
apparatus provided with mechanical stirrers, closed and ventilated
mechanical dipping and drying apparatus, are especially important.
Certain modern American machines carry through the whole complicated
process of the phosphorous match industry automatically. Seeing that
prohibition of white phosphorus is an accomplished fact and that matches
free from risk in their manufacture answer every purpose, the universal
enforcement of the prohibition of white phosphorus should be striven for
in civilised states.
Carbon bisulphide
(See also pp. 68-71 and 193-5)
Use of carbon bisulphide in the vulcanising of indiarubber goods by
dipping them into the liquid and subsequently drying them (usually in
a current of hot air) causes development of carbon bisulphide fumes in
considerable quantity, especially if the articles to be dried are laid
on shelves or hung up in the workroom, a procedure which should never be
permitted. Drying must be carried out under local exhaust ventilation.
All vessels holding carbon bisulphide used for dipping can be placed in
a wooden channel above the dipping vessels, provided with openings for
manipulation, and connected with an exhaust system.
The following are the German Imperial Regulations, dated March 1, 1902,
for vulcanising of indiarubber by means of carbon bisulphide:
VULCANISING BY MEANS OF CARBON BISULPHIDE
(Notice concerning the erection and management of industrial
premises in which indiarubber goods are vulcanised by means of
carbon bisulphide or chloride of sulphur.)
The following regulations shall apply in accordance with
paragraph 120 (_e_) of the Industrial Code:
1. The floor of such rooms as are used for the vulcanising
of indiarubber goods by means of carbon bisulphide shall not
be lower than the surrounding ground. The rooms shall have
windows opening into the outer air, and the lower halves shall
be capable of being opened so as to render possible sufficient
renewal of air.
The rooms shall be ventilated by fans mechanically driven. With
the approval of the higher authorities permission to dispense
with mechanical draught may be allowed, provided that in other
ways powerful change of air is secured. With the approval of
the higher authorities special ventilating arrangements can be
dispensed with if the fumes of carbon bisulphide are removed
immediately, at the point where they are produced, by means
of a powerful draught, and in this way purity of the air be
secured.
2. The vulcanising rooms shall not be used as a dwelling, or
for sleeping in, or for preparing food in, or as a store,
or drying room, nor shall other processes than those of
vulcanising be carried on in them. No persons, except those
engaged in vulcanising processes, shall be allowed in the rooms.
There shall be at least 20 cubic meters (700 cubic feet) of air
space allowed for each person employed therein.
3. Only such quantities of carbon bisulphide shall be brought
into the vulcanising rooms as shall serve for the day’s supply.
Further storage shall be made in a special place separate from
the workrooms. Vessels to hold the vulcanising liquid shall be
strongly made, and when filled and not in use shall be well
covered.
4. Vulcanising and drying rooms shall be warmed only by steam
or hot-water pipes.
These rooms shall be lighted only by means of strong
incandescent electric lamps.
Exceptions from paragraphs 1 and 2 may be allowed by the higher
authorities.
5. Machines intended for vulcanising long sheets of cloth shall
be covered over (_e.g._, with a glass casing) so as to prevent
as far as possible the entrance of carbon bisulphide fumes into
the workrooms, and from the casing the air shall be drawn away
effectually by means of a fan mechanically driven. Entrance to
the space which is enclosed shall only be allowed in case of
defects in the working.
In cases where a covering of the machine is not practicable
for technical reasons the higher authorities can, if suitable
means of protection are used (especially when the machine is
placed in an open hall, and provided that no person works at
the machine for more than two days a week), allow of exception
to the above arrangement.
6. Vulcanising of other articles (not mentioned in par. 5),
unless carried out in the open air, shall be done in covered-in
boxes into which the worker need only introduce his hands, and
so arranged as to keep the fumes away from the face of the
worker.
The air must be drawn away from the box by means of a powerful
draught.
7. Rule 6 shall apply in vulcanising both the outside and
inside of indiarubber goods. In vulcanising the inside no
worker shall be allowed to suck the fluid through with the
mouth.
8. The goods after their immersion in the vulcanising fluid
shall not lie open in the room, but shall either be placed
under a ventilated cover or at once be carried into the drying
chamber.
The drying chamber or drying rooms in which the wares are
exposed to artificial heat immediately after vulcanising
shall be so arranged that actual entrance into them for the
putting in or taking out of the vulcanised goods shall not
be necessary. No person shall be allowed to enter the drying
chamber while work is going on. The higher authorities can
permit of exceptions to this rule in the case of the drying of
long rolls if sufficient protecting arrangements are made.
9. When vulcanisation is effected by means of chloride of
sulphur the vessels or chambers used for holding it shall be so
arranged that escape of the fumes is prevented.
No person shall enter the vulcanising chamber until the air in
the chamber has been completely changed; it shall not be used
for purposes other than vulcanising.
10. Employment in vulcanising with carbon bisulphide or in
other work exposing the workers to carbon bisulphide vapour
shall not be allowed without a break for more than two hours
and in no case for more than four hours in one day; after two
hours a pause of at least one hour must be allowed before
resumption.
No person under 18 years of age shall be employed.
11. The occupier shall provide all workers employed in work
mentioned in paragraph 10 with proper and sufficient overalls.
By suitable notices and supervision he shall see that when not
in use they are kept in their proper place.
12. Separate washing accommodation and dressing-rooms for each
sex shall be provided, distinct from the workrooms, for all
persons employed as stated in paragraph 11.
Water, soap, and towels and arrangements for keeping the
clothes put off before the commencement of work shall be
provided in sufficient amount.
13. The occupier shall appoint a duly qualified medical
practitioner (whose name shall be sent to the Inspector of
Factories) to supervise the health of those exposed to the
effects of carbon bisulphide. He shall examine the workers once
every month with a view to the detection of poisoning by carbon
bisulphide.
By direction of the medical practitioner workers showing signs
of carbon bisulphide poisoning shall be suspended from work
and those who appear peculiarly susceptible shall be suspended
permanently from work in processes mentioned in paragraph 10.
14. The occupier shall keep a book, or make some official
responsible for its keeping, of the changes in the personnel in
the processes mentioned in paragraph 10 and as to their state
of health. The book shall contain—
(1) The name of the person keeping the book;
(2) The name of the appointed surgeon;
(3) Surname, Christian name, age, residence, date of first
employment, and date of leaving of every worker mentioned in
paragraph 10, and the nature of the employment;
(4) The date of any illness and its nature;
(5) Date of recovery;
(6) The dates and results of the prescribed medical examination.
15. The occupier shall require the workers to subscribe to the
following conditions:—
No worker shall take food into the vulcanising rooms;
The workers shall use the protection afforded in paragraphs 5-7
and use the overalls in the work named;
The workers shall obey the directions of the occupier given in
accordance with Rule 5, paragraphs 1 and 2, Rule 8, paragraphs
1 and 2, and Rule 9, paragraph 2. Workers contravening these
orders shall be liable to dismissal without further notice.
If in a factory regulations already exist (paragraph 134(a) of
the Industrial Code) the above shall be included.
16. In the vulcanising rooms mentioned in Rule 1 there shall be
posted up a notice by the police stating—
(_a_) The cubic capacity of the rooms;
(_b_) The number of workers who may be employed.
Further, in every vulcanising room there shall be posted up in
a conspicuous place and in clear characters Rules 1-15 and the
conditions in paragraph 15.
Reference should be made also to the Prussian Ministerial Decree, dated
February 23, 1910, on the preparation, storing, and manufacture of carbon
bisulphide, and to the French Ministerial Circular, dated January 20,
1909 (Manufacture of Indiarubber).
Employment of benzine and chloride of sulphur for vulcanising is, from a
hygienic standpoint, to be preferred to that of the much more dangerous
carbon bisulphide. The same applies also to the process of the extraction
of fat.
In the references made to general arrangements for the protection of
workers dealing with poisons, stress was laid on the complete enclosing
of extraction apparatus. This applies, of course, to extraction by means
of carbon bisulphide, both on grounds of economy, health, and risk from
fire.
On account of the risk to health, efforts have been made to substitute
other means of equal efficiency, free from danger. Such a substitute may
be found in _carbon tetrachloride_. This extracts well, and dissolves
grease spots (like benzine), is not explosive, is scarcely inflammable,
and is less poisonous than the substances commonly used for extraction.
Its employment is to be recommended on hygienic grounds, but the
relatively high price may stand in the way of its use.
Illuminating Gas Industry. Production of Tar and Coke
(See also pp. 71-90 and 199)
In illuminating gas factories imperviousness of the whole working system
is especially important from an economical and hygienic standpoint,
since only in this way can danger to the working staff be avoided. This
applies especially to the retorts, from which no gas should be allowed
to escape. If the exhaust is working satisfactorily this should not be
possible, as the pressure of the gas in the retorts during distillation
will be a negative one. Correct regulation of pressure is thus of the
greatest importance in the prevention of poisoning in gas works.
Further, special precaution is necessary in operations with gas purifying
material containing cyanogen, since otherwise the workers suffer from the
gases developed from the gas lime.
Work with gas purifying material should be so arranged that injurious
gases are carried away by suitable ventilating arrangements.
Consideration for the neighbourhood forbids their discharge into the open
air, and forbids also operations with the gas purifying material in the
open air; therefore non-injurious removal of these gases is necessary.
Quenching of the coke also should, on account of the annoyance to the
working staff and to lessen nuisance to the neighbourhood, be carried out
so that the fumes are drawn into the main chimney stack.
In coke ovens escape of tarry constituents and of poisonous emanations
are prevented by imperviousness of the apparatus, by sufficiency of the
exhaust draught, and especially by passing the products of distillation,
which cannot be condensed, under a fire, or by absorbing them either with
water or oil.
Special precautionary measures are needed further in the distillation of
the washing oil, and generally escape of poisonous emanations must be
prevented by the greatest possible imperviousness of the distillation
system and corresponding regulation of pressure.
Gas Motors (Power Gas Stations)
(See also pp. 80-5)
The following points, taken from an Austrian Ministerial Decree (dated
December 2, 1903), for the prevention of poisoning in power gas works,
may be useful:
POWER GAS INSTALLATIONS
In mixed gas installations (Dowson, water gas) of the older
system, the way in which the gas is produced causes the whole
apparatus and pipes to be under slight negative pressure,
because the steam required for the process must be blown into
the generator. In these works, therefore, a small special steam
boiler is required and a gas receiver to store the gas.
In more modern suction generator gas installations the piston
is used to suck in steam and air as well as the gases arising
in the generator and to draw them into the motor cylinder. Thus
the whole system is kept in a condition of slight negative
pressure during the process. While the suction generator gas
system is working, only so much gas is produced as the motor
uses for the time being, so that with this system there is no
greater store of gas than is requisite.
In such an installation the following rules should be borne in
mind:
1. All the apparatus (gas pipes, valves, &c.) must be
constructed and maintained in a completely impervious
condition. Any water seals especially which may be in use must
receive attention.
2. Precautions must be taken to prevent the gases from the
generator passing into the coolers and purifiers when the
engine is at rest.
3. Care is to be taken when the apparatus is at rest to prevent
any possible subsequent escape of gas into the room where the
apparatus is installed.
4. The return of explosive gas out of the gas engine into the
gas pipe by failure to ignite or other accident, must be made
impossible.
5. The apparatus through which the generator is charged must
possess a tightly fitting double valve to prevent escape of gas
into the room during charging.
6. The pipes for conducting away the unpleasantly smelling
bituminous constituents in the water mixed with sulphuretted
hydrogen from the scrubbers must not communicate with the
workroom.
7. Precautions must be taken to minimise the danger during the
cleaning of the generator (removal of ashes and slag).
8. All stop-cocks and valves are to be so arranged that their
position at any time (open or shut) is clearly visible from
outside.
9. Purifiers with a capacity greater than two cubic meters
must be provided with appliances which make possible thorough
removal of the gas before they are opened.
10. The gas washing and cleaning apparatus and pipes are to be
fitted with gauges indicating the pressure existing in them at
any moment.
11. When a suction gas plant is first installed and also at
times when there is no gas in the pipes and plant between the
generator and the engine, gas must be blown in until all air is
expelled before the engine is set going.
12. During the cleaning of apparatus and pipes which, when in
action, contain gas, the rooms must be thoroughly ventilated.
13. Rooms in which suction gas plant is installed must be of
such a height that all the plant and its connections can be
easily reached for cleaning, &c., and be capable of such free
ventilation as to render impossible an accumulation of gas.
14. These rooms must be separated from living rooms by a wall
without any openings in it. Emanations also must be prevented
as far as possible from entering into living or working rooms
situated over the gas engine.
15. Erection of apparatus for generating and purifying suction
gas in cellars shall only be allowed if specially effective
ventilation is provided by natural or mechanical means.
Other Regulations are those of the Prussian Ministerial Decree, dated
June 20, 1904, as to the arrangement and management of suction gas
premises.
ACETYLENE GAS INSTALLATIONS
(See also pp. 85-7)
The following regulations for the protection of workers in acetylene gas
installations are taken from the Prussian Ministerial Decree, dated 2
November, 1897:
1. Preparation and condensation of acetylene on the one hand,
and liquefaction on the other, must be carried on in separate
buildings.
2. If the pressure employed for condensation of the gas exceeds
eight atmospheres, this work must take place in a room set
apart for the purpose.
3. Rooms in which acetylene is prepared, condensed, or
liquefied shall not be used as, nor be in direct connection
with, living rooms. They must be well lighted and ventilated.
4. The carbide must be kept in closed watertight vessels, so
as to ensure perfect dryness and only such quantities shall
be taken out as are needed. The vessels must be kept in dry,
light, well-ventilated rooms; cellar rooms may not be used for
storage purposes.
5. Crushing of carbide must be done with the greatest possible
avoidance of dust. Workers are to be provided with respirators
and goggles.
6. Acetylene gasometers must be fitted up in the open air or in
a well-ventilated room, separated from the gas generator. Every
gas receiver must have a water gauge showing the pressure in
the receiver.
7. Between the gasometer and receiver a gas purifier must be
provided so as to remove impurities (phosphoretted hydrogen,
arseniuretted hydrogen, carbon bisulphide, ammonia, &c.).
8. Condensation of acetylene gas at a pressure exceeding ten
atmospheres shall only be done in combination with cooling.
DISTRIBUTION AND USE OF POWER AND ILLUMINATING GAS
The Austrian Gas Regulations (of July 18, 1906) contain general
provisions as to impermeability and security of the gas pipes and the
precautions to be observed in their installation. Special directions
follow as to main flues, material, dimensions, branches, and connections,
valve arrangements, testing of the pipes against leakage, directions
for discovering leaks, and other defects; also the nature of the branch
pipes (dimensions and material), valves, cocks, syphons, water seals, and
pressure gauges. In addition there are directions as to testing pipes and
how to deal with escape of gas, freezing of pipes, and other mishaps.
Ammonia
(See also pp. 90-3 and 175)
In the production of ammonia and ammonium salts (ammonium sulphate)
combination of the ammoniacal vapour with the sulphuric acid is
accompanied with the formation of volatile dangerous gases containing
sulphuretted hydrogen and cyanogen compounds, which produce marked
oppression and sometimes endanger the health of the workers. Drawing-off
these fumes into the furnace (practised sometimes in small industries)
is not advisable, as the sulphuretted hydrogen is burnt to sulphur
dioxide; if it is burnt absorption of the sulphur dioxide should follow,
or working it up into sulphuric acid (Leymann). Often these gases are
freed from cyanogen compounds and sulphuretted hydrogen by means of gas
purifying materials, such as are used in gas works. The whole apparatus
must be impervious. Where liquids containing ammonia are used exhaust
ventilation is necessary.
Cyanogen, Cyanogen Compounds
(See also pp. 93-5 and 195-7)
Processes in which cyanogen gas can develop, require to be done under a
powerful exhaust draught.
In the production of cyanogen compounds possibility of the escape of
hydrocyanic acid (prussic acid) has to be borne in mind. Such escape is
possible in its production from raw animal products.
The most careful cleanliness and observance of general measures for
personal hygiene are necessary in factories in which cyanogen compounds
are manufactured or handled. In crushing cyanide of potassium the workers
should wear indiarubber gloves and respirators. The products should be
stored in closed vessels in dry store rooms set apart for the purpose.
Modern cyanide of potassium factories which work up molasses, from which
the sugar has been removed, and also residuary distillery liquors, so
far conform with hygienic requirements that all the apparatus is under
negative pressure, so that poisonous gases cannot escape into the
workrooms.
Coal Tar, Tar Products
(See also pp. 96-119)
Care must be taken for the removal of injurious gases developed in the
manipulation and use of tar (tar distillation) and in the processes
of cleaning connected therewith. This can be most effectively done by
carrying on the processes in closed apparatus. Hofmann describes such
a factory where all mixing vessels in which the distillation products
are further treated are completely closed in, so that even in mixing and
running off, no contact is possible with the material.
The vessels for holding tar, tar-water, &c., must be impervious and
kept covered. Only the cold pitch and asphalt should be stored in open
pits. The cooling of the distillation products and residues, so long as
they give off poisonous and strongly-smelling fumes, should be carried
out in metal or bricked receivers. Such directions find a place in the
‘Technical Instructions’ appended to the German Factory Code. Without
doubt, tar is, because of its smell and for other reasons, unpleasant to
handle, and the danger to health from contact with it is not a matter
of indifference. Spilling of small quantities of tar during transport
and other manipulations can hardly be avoided. Careful cleanliness,
therefore, on the part of workers is strongly urged. It may be mentioned
that if tar is covered with a layer of tar-water, treatment with acid
fluids develops sulphur and cyanogen compounds, which may affect the
workers. Tar water should, therefore, be separated carefully from the tar
and used for the preparation of ammonia.
The same remarks as to cleanliness, &c., apply in the manufacture of
felt, lamp-black, and briquettes, with use of tar. Saturation of felt,
and manufacture of tar plaster should be done in closed apparatus.
In the production of lamp-black, even with a great number of soot
chambers, there is escape of soot causing nuisance to workers and the
neighbourhood. Complete avoidance of this seems to be difficult, so that
measures for personal hygiene must be assured. In briquette factories it
has been found useful to heat the tar by means of steam instead of by
direct fire, which renders possible the use of a closed apparatus and
mechanical stirring.
In the distillation of tar, during the first distillation period (first
runnings) unpleasant and injurious gases containing ammonia and sulphur
escape from the stills. These should (according to Leymann) be carried
away through closed pipes branching off from the lower end of the
running-off pipe, either into the furnace (in doing which a possible back
flash of flame is to be guarded against) or be subjected to purification
by lime or oxide of iron (similar to that in the case of illuminating
gas) with a view to recovery of ammonia and sulphur. The lower end of the
distillation pipes should be U-shaped so as to form a liquid seal—the
pipes for the drawing off of the gases branching off before the curve. In
the later stages of distillation risk can be checked by careful cooling
and imperviousness of the apparatus.
Very unpleasant yellow fumes develop in great quantity when pitch is run
off from the hot still. Hence hot pitch should not be run off into open
pitch receptacles, but be cooled first in closed receptacles.
The crude products obtained by distillation (light oil, creosote oil)
are subjected to purification consisting in treatment on the one hand
with alkali and on the other with acid and followed by fractional
distillation. In these processes injurious fumes may develop, therefore
they must—as already mentioned—be carried on in closed vessels provided
with means of escape for fumes and appliances for mechanical stirring;
the fumes drawn off must be led into the chimney stack.
In the distillation of brown coal, of tar, and of resin, it is necessary,
as in the distillation of coal tar, to insist above all on careful
cooling and condensation, and thorough absorption of uncondensed gases
in washing towers. Special precautionary rules are necessary to guard
against the danger of entering tar stills for cleaning purposes. Such
directions were approved in Great Britain in 1904 in view of accidents
which occurred in this way:
TAR DISTILLING
The following directions[I] are approved by the Home Office
and are applicable to factories in which is carried on the
distillation of tar for the production of naphtha, light oil,
creosote oil, and pitch.
1. During the process of cleaning, every tar still should
be completely isolated from adjoining tar stills either by
disconnecting the pipe leading from the swan neck to the
condenser worm, or by disconnecting the waste gas pipe fixed
to the worm end or receiver. Blank flanges should be inserted
between the disconnections. In addition, the pit discharge pipe
or cock at the bottom of the still should be disconnected.
2. Every tar still should be ventilated and allowed to cool
before persons are allowed to enter.
3. Every tar still should be inspected by the foreman or other
responsible person before any workman is allowed to enter.
4. The inspecting foreman on first entering any tar still
or tank, and all persons employed in tar stills or tanks in
which there are no cross stays or obstructions likely to cause
entanglement, should be provided with a belt securely fastened
round the body with a rope attached, the free end being left
with two men outside whose sole duty should be to watch and
draw out any person appearing to be affected by gas. The belt
and rope should be adjusted and worn in such a manner that the
wearer can be drawn up head foremost and through the manhole
and not across it.
5. A bottle of compressed oxygen, with mouthpiece, should be
kept at all times ready for use; and printed instructions as
to the use of this bottle, and the method to be employed for
resuscitation by means of artificial respiration should be kept
constantly affixed. A draft of such instructions is appended.
6. A supply of suitable chemical respirators properly charged
and in good condition should be kept ready for use in case
of emergency arising from sulphuretted hydrogen or certain
poisonous gases. (Granules of carbon saturated with a solution
of caustic soda readily absorb sulphuretted hydrogen and may be
used for charging respirators.)
7. The use of naked lights should be strictly prohibited in
any portion of the works where gas of an inflammable nature is
liable to be given off.
8. Each still should be provided with a proper safety valve,
which should at all times be kept in efficient working
condition.
GASSING
_Symptoms._—The first symptoms are giddiness, weakness in the
legs, and palpitation of the heart. If a man feels these he
should at once move into fresh warm air, when he will quickly
recover if slightly affected. He should avoid exposure to cold.
He should not walk home too soon after recovery; any exertion
is harmful.
_First Aid._—Remove the patient into fresh warm air. Send for
the oxygen apparatus. Send for a doctor. Begin artificial
breathing at once if the patient is insensible and continue it
for at least half-an-hour, or until natural breathing returns.
Give oxygen[J] at the same time and continue it after natural
breathing returns.
_Artificial Breathing_ (_Schäfer Method_).—Place the patient
face downwards as shown in the diagrams.
Kneel at the side of the patient and place your hands flat in
the small of his back with thumbs nearly touching, and the
fingers spread out on each side of the body over the lowest
ribs (_see_ Diagram 1).
[Illustration: DIAGRAM 1]
Then promote artificial breathing by leaning forward over the
patient and, without violence, produce a firm, steady, downward
pressure (_see_ Diagram 2). Next release all pressure by
swinging your body backwards without lifting your hands from
the patient (_see_ Diagram 1).
[Illustration: DIAGRAM 2]
Repeat this pressure and relaxation of pressure without any
marked pause between the movements, _about 15 times a minute_,
until breathing is established.
In my opinion as expressed in the general discussion, use of breathing
apparatus (smoke helmets) with oxygen is strongly advisable; these
implements must be put on before entering the still.
In creosoting wood, opening the apparatus and taking out the steeped
wood should only be done when the apparatus is sufficiently cooled, as
otherwise injurious fumes escape.
In heating asphalt unpleasant fumes arise which should be drawn off into
a furnace, or absorbed by a condenser charged with oil (Leymann); open
pans should be avoided, as injurious to workers.
Organic Dye-stuffs, Coal-Tar Colours.
(See also pp. 107-19 and 204-15)
The hygienic measures to be adopted for the prevention of industrial
poisoning in coal-tar colour factories are chiefly concerned with the
poisonous nature on the one hand of the raw material (benzene, toluene,
&c.) and on the other of the intermediate products (nitrobenzene,
aniline, toluidine, &c.) and the subsidiary substances (chlorine, acids,
especially nitric acid, &c.,) used.
The most important measures are as follows:
In purifying the raw materials (benzene, &c.) the distillation requires
to be done under effective cooling and in impervious apparatus. If
injurious solvents are employed (such as pyridine in the production of
anthracene) the manipulations should be performed in closed apparatus
if possible, under negative pressure. The fumes exhausted should be
carefully condensed by cooling or absorbed by a spray of water or oil.
In view of the poisonous nature of benzene, the apparatus, stills,
receivers, tanks, tank waggons, &c., should only be entered for the
purpose of cleaning or repairing after preliminary thorough removal of
all residue of benzene, complete isolation from all similar apparatus
near, and thorough ventilation. Workers entering the stills, &c.,
should always be equipped with breathing apparatus (smoke helmets) and
with a supply of oxygen. Other aids, such as safety belts which are held
by helpers, are not here advocated in view of the often sudden fatal
poisoning, especially as the rescuer is easily induced to spring to the
assistance of his unfortunate mate without the necessary equipment. The
frequency of such accidents calls urgently for the use of breathing
apparatus.
In the manufacture of _diazo-_ and _nitroso-compounds_ and generally in
nitrating operations poisonous nitrous fumes are developed. By reduction
in an acid solution, acid fumes and singularly pungent-smelling compounds
can be given off. If reduction by means of tin is practised, the arsenic
in the tin can cause evolution of the extremely poisonous arseniuretted
hydrogen gas. In sulphonating, sulphur dioxide can develop; and
sulphuretted hydrogen gas on heating with sulphur or sulphide of sodium.
All manipulations should take place in tightly closed-in apparatus
provided with exhaust, and the gases drawn off should be absorbed or
effectively carried away. In the case of many injurious gases it is
not sufficient merely to conduct them into the flue; they ought to
be condensed and got rid of. Thus acid fumes (nitrous fumes, sulphur
dioxide, hydrochloric acid vapour, chlorine gas) are neutralised by water
or milk of lime, or a solution of soda; ammonia or alcohol by water;
sulphuretted hydrogen and arseniuretted hydrogen by lime and oxide of
iron; aniline, &c., by dilute acids.
Production of _nitrobenzene_, by nitrating benzene requires to be done in
closed apparatus, provided with mechanical agitators. In the subsequent
separation of the nitrating acids from the resulting nitro-compounds,
escape of vapourised nitro-compounds can scarcely be avoided even if
closed apparatus is used. Provision, therefore, must be made for abundant
ventilation of the workrooms. The reduction of the nitro-compounds
(nitrobenzene, nitrotoluene) to aniline (toluidine) must similarly take
place in closed agitating vessels. Introduction of the iron filings and
sulphuric or hydrochloric acids, also the subsequent saturation with
lime, and driving over of the aniline, &c., with steam, and collection
of the distillate, must take place in completely closed apparatus.
Nevertheless, escape of small quantities of aniline is very difficult to
prevent unless ample ventilation is provided.
In the production of _fuchsin_ by heating aniline hydrochloride
(toluidine, red oil) with nitrobenzene (formerly arsenic acid) in closed
vessels, furnished with mechanical stirring apparatus the aniline
remaining unconverted after the melting escapes in the form of steam
carrying aniline fumes, even with careful condensation, so that thorough
ventilation and the other general measures for the protection of workers
set forth on pp. 242 _et seq._ are required.
Marked injury to health and distress to workers through acid fumes are
sometimes caused by the denitration of the waste mixture of sulphuric
and nitric acids in the nitrating process, that is, by the separation of
nitric acid from the acid mixture. This denitration takes place usually
in the Glover towers of the lead chamber system which is often associated
with the manufacture of aniline. The mixed nitro-compounds of the waste
acids, however, are often not completely condensed, but pass through the
chambers and Gay-Lussac towers and escape into the air, whence arises
the constant smell of nitrobenzene in aniline factories (Leymann). In
the production of _naphthylamine_ and recovery of chlorinated products,
escaping chlorine should be led into chloride of lime chambers,
hydrochloric acid fumes into towers to be absorbed by water and milk of
lime or a solution of soda.
In aniline factories danger can scarcely be wholly avoided, as the
workers, on the one hand, come into contact with poisonous substances,
nitrobenzene, aniline, &c., and on the other hand, in spite of all
technical hygienic measures, can hardly help breathing in some of the
aniline. Apart from the technical regulations, therefore, there must
be insistence on cleanliness of the workrooms, personal cleanliness on
the part of the workers (washing, baths, working suits, cloak-rooms,
&c.). Besides this, contact with aniline, nitrobenzene, &c., wetting of
the body and clothes with these substances, and, especially spilling,
splashing, and scattering these fluids must be carefully avoided.
The workers require to be suitably instructed as to the symptoms of
nitrobenzene and aniline poisoning, and the right steps to take, if
poisoned. The oxygen apparatus must always be at hand, ready for use; the
workers must be instructed how to use it. Further, workers, especially
those newly employed, must be under supervision in order that assistance
may be rendered them on the first signs of poisoning; medical assistance
ought to be within easy reach. Workers also should know of the tendency
of aniline to cause cancer of the bladder.
Precautions against the poisonous nitro-derivatives of benzene
(nitrophenol, picric acid, &c.), which are in the form of poisonous dust,
must take the form of entirely closed-in grinding and packing apparatus,
or, at all events, removal of the dust at its source.
Among official regulations may be mentioned the Prussian Ministerial
Edict, dated December 18, 1908, as to purification and storage of
benzene, and further the Regulations dated December 13, 1907, and
December 30, 1908, in force in Great Britain for the manufacture
of nitro- and amido-derivatives of benzene, and the manufacture of
explosives with use of dinitrobenzene or dinitrotoluene.
VI
_PREVENTIVE REGULATIONS—THE EXTRACTION OF METALS (SMELTING WORK IN
GENERAL)_
Danger is incurred when the furnace leaks, a condition which generally
occurs in the course of time, or if gases escape during the necessary
manipulations through the working doors. This can be avoided by
maintaining the walls in as air-tight a state as possible; but as very
small leakages are almost unavoidable the best course is to so regulate
the draught in the furnace (by means of fans) that a slight negative
pressure always exists in it. Naturally, poisonous gases escaping from
the furnace such as sulphur dioxide, carbonic oxide, carbon dioxide,
and hydrocarbons require to be drawn away and rendered harmless. This
can often be done by merely conducting them into the main flue. Gases
containing carbonic oxide possess high heating capacity, and their
escape can usually be prevented by suitable cupola bells. They can be
led away in impervious conduits and utilised for heating purposes or
for driving gas engines. Entering the flues for cleaning or repairing
purposes is especially dangerous; and as it is difficult to isolate one
portion entirely from another, such operations might well be carried on
by persons equipped with breathing apparatus (smoke helmets or oxygen
apparatus).
In roasting operations handwork can be largely replaced by furnaces
worked mechanically. If the gases generated are rich in sulphur dioxide
they can be utilised for the manufacture of sulphuric acid or for
the production of liquid sulphur dioxide either directly or after
concentration; if not, they must be rendered harmless by treatment with
milk of lime in absorption towers. Other methods of rendering the sulphur
dioxide (unsuited for manufacture of sulphuric acid) harmless depend on
treatment with minerals containing calcium carbonate, or magnesium or
aluminium hydrate, sodium sulphide, &c. Sometimes the sulphurous gases
are led into blast furnaces containing oxide of iron and coal (so as to
form sulphide of iron) or are absorbed by means of moist scraps of sheet
iron or brown coal or peat briquettes.
Use of chlorine compounds in the extraction of metals from ores (silver,
copper) causes evolution of chlorine and hydrochloric acid vapour. These
should be dealt with in absorption towers. Metallic fumes are collected
by suitable condensing arrangements. Flue dust is retained in flue dust
chambers, but in the cleaning of such condensing flues and chambers
danger to the workers is considerable and they should be equipped with
respirators, working suits, &c. Personal hygiene must be insisted on.
Iron
(See also pp. 146-51)
In blast furnace work, industrial poisoning occurs mainly from escaping
gases rich in carbonic oxide. They may also contain sulphur dioxide and
cyanogen compounds. The high proportion of carbonic oxide, however, makes
these gases valuable and serviceable, because of their great heating
value. They are, therefore, now led away and utilised, the furnace being
closed by a cupola bell only opened by means of a mechanical contrivance
when charging is necessary; while this is being done the ignited blast
furnace gases pour out, and the workers retire from the opening, so
that danger to them is avoided. The construction of a blast furnace
with a cupola bell can be seen in fig. 29. The blast furnace gases are
conducted away by an opening in the side, and pass along special pipes
to be utilised, after having gone through a purifying process mainly for
the removal of flue dust, &c. The gases serve partly for the heating of
the blast for the furnace itself, and partly for driving the gas engines
which serve the electrical power apparatus, electric lighting, &c., in
the works. Through the rational utilisation of the blast furnace gases,
the workers are protected from their injurious action during the working
of the furnace. Serious gas poisoning, however, occurs not infrequently
to workers who have to enter the gas mains for cleaning purposes.
Workers, therefore, should only be permitted to enter the flues, &c.,
a considerable time after the process has been stopped and after as
complete and thorough a ventilation of the system as is possible.
Any portion of the gas system which is to undergo cleaning must be
completely isolated. Ventilation is best effected by the introduction of
compressed air. Thus a foundry (in the Duisburg district) has provided
all its cellars and passages, through which gas pipes pass, and which
must be entered during repairs, with compressed air pipes. It is,
however, advisable that gas conduits should only be entered by workers
equipped with breathing apparatus and oxygen supply. Naturally adequate
instruction of workers and training in first aid are necessary, as well
as a sufficient supply of oxygen in constant readiness.
Injurious gases can escape from the furnace during tapping and slag
running; poisonous gases with a disagreeable odour, from presence of
sulphuretted hydrogen, also arise in granulating the slag, that is, when
the fluid slag is led into water for subsequent use in preparation of
cement. These gases should be collected by hoods, and be carried away as
far as possible.
In the manufacture of _steel_ by the _Bessemer_ or _Thomas-Gilchrist_
process, the dark smoke arising out of the converter during the blowing
operation should be drawn off (led into flues), as it is injurious to
health. In the _Martin_ furnaces poisoning may occur, especially when
the gas flues are entered after cessation of work. In letting out the
gas in order to stop the furnaces, the gas and air valves must first be
closed and the outlet valves for gas be opened only after the pipes have
been filled with steam. Steam is to be driven through until the pipes
are quite free from gas, and the system only entered after it has become
thoroughly cooled. If need arises for entering portions of the system
while neighbouring parts are still filled with gas, the workers employed
require to be provided with breathing apparatus and smoke helmets.
In the transport of _ferro-silicon_ several cases of poisoning have
occurred. Cautionary regulations, therefore, relating to this work have
been found necessary.
Such directions are contained in the police regulations of the Prussian
Minister of Trade and Industry respecting the transport on the Rhine of
corrosive and poisonous substances (dated September 29, 1910).
It is prescribed: (1) that ferro-silicon be packed in strong watertight
cases of wood or metal; (2) that on the cases be inscribed, legibly and
indelibly, the notice ‘Ferro-silicon. To be kept dry! With care!’ (3)
that the substance be delivered dry and in dry cases; (4) that the cases
be stored in airy places on the deck of the ship in such a manner that
they are protected from wet.
Further, care is to be taken that the storage on ships is done in such a
way that possible damage to the material in which it is packed entails no
risk. The harbour authorities where loading or landing takes place can
deal with special cases as they think fit.
International regulation as to transport of ferro-silicon in the spirit
of the above regulations would be most desirable in view of the oversea
trade in this substance.[K]
Lead
(See also pp. 120-40 and 177-82)
For protection against lead poisoning, the most widely spread of the slow
industrial poisonings, all those measures are of moment which we have
described in our general discussion on protection against danger from
poison in industries, both personal and general.
Personal hygiene, especially careful washing after work, prohibition of
eating in workrooms, suitable working clothes, provision of cloak rooms,
meal rooms, baths, &c., are important and effective measures for the
protection of workers against industrial lead poisoning.
The worker should naturally be adequately instructed as to the risk.
Appropriate printed notices are especially adapted for this purpose.
Further, selection of workers should be made under medical supervision.
Workers who suffer from specific disease which, if associated with lead
poisoning, may prove dangerous, should be excluded from all contact
with lead. Among such illnesses must be reckoned tuberculosis in all
its forms, alcoholism, epilepsy, tendency to mental disease (nervous
disposition, hysteria, neurasthenia, &c.), rheumatism, and disease of the
kidneys.
Overtime work undoubtedly increases risk; therefore working hours should
be shortened as much as possible, and handwork replaced by machine work
where possible. Young persons and women especially should be excluded
from work in lead. Alternation of employment also is beneficial and
essential in very dangerous lead work, because the poison accumulates in
the body and only during intervals wherein absolutely no poison can be
absorbed has it time to be eliminated.
Periodical medical examination by a surgeon is of great value with
systematic entry of the results of examination in a health register. As
bearing on this, early diagnosis is of the greatest importance, so that
workers in whom the first signs of lead poisoning appear may at once be
suspended or transferred to other work.
Lead workers should take suitable nourishing food and avoid particularly
alcoholic excess.
When the danger is due to fumes or dust in the air the measures
prescribed on pages 242-55 apply, particularly those which aim at keeping
the workrooms and the air in the factories free of them by locally
applied exhaust ventilation.
In order to replace or reduce the use of lead we strongly advocate the
use of non-poisonous, or at any rate less poisonous, substances, where
this can be done without technical difficulties, as, for instance,
carborundum discs instead of lead in polishing of precious stones,
leadless glaze in pottery for lead glaze (so far as this is possible,
as to which see page 319), beds free of lead (in different industries)
for lead beds. In a number of cases, however, such substitution is
impracticable on technical grounds or can only partially be carried out,
as, for example, in letterpress printing and in the paint and colour
industry, in which the prohibition of lead has often been repeatedly
urged. So far, unfortunately, it must be admitted that repeated attempts
to find a non-poisonous substitute for lead colours, especially for
white lead, of equal value technically, have not succeeded. Endeavours
have been made to substitute for lead, zinc preparations (zinc white,
lithopone, &c.), but hitherto (in regard to durability, opacity, &c.)
with incomplete success.
Mention must be made of the measures based upon the relatively
non-poisonous nature of lead sulphide. Lead sulphide is, in spite of
various assertions to the contrary, practically non-poisonous; a fact
attributable to its insolubility in water and weak acids. As lead
sulphide is the only non-poisonous lead compound it is a duty to take
advantage of this fact for purposes of lead prophylaxis.
Attempts with this end in view were made by the introduction of sulphur
soaps in lead factories. Soaps containing in large quantity soluble
alkaline sulphides convert lead compounds adhering to the skin into
black lead sulphide. The lead compounds are in this way made harmless,
and besides this the worker is impelled to remove the staining by
washing. Such a sulphur soap has been brought into the market under the
name of akremnin soap, but does not enjoy special popularity with the
workmen on account of its unpleasant smell.
The struggle against the risks of lead employment has been going on ever
since efforts for the protection of workers were commenced.
The International Association for Labour Legislation has made valuable
inquiries in this direction. The question of lead poisoning had been
repeatedly discussed by this Association and its branches in various
countries. The International Labour Bureau also took up the issue and
in 1906—supported by the Institute for General Welfare in Frankfurt
a-M.—offered a prize for the best treatise on the prevention of
industrial lead poisoning. The outcome of this competition was the volume
compiled by Leymann, ‘Die Bekämpfung der Bleigefahr in der Industrie’
(published by Fischer, Jena, 1908).
In connection with the resolution adopted at the third Congress of the
International Association for Labour Legislation the Union of Social
Reform (as the German branch is called) addressed the Federal Council on
the white lead question, the chief points insisted upon being the need
for: (1) regulations for the house painting industry in pursuance of