Chapter XI: Part I (6)

Use of _arsenic colours_ is becoming less and less. But in colour printing of paper and colouring of chalk they are still employed. They are used, too, as mordants in dyeing, but cases of poisoning from these sources in recent years are not to be found.

The dust in many glass works contains, it is stated, as much as 1·5 per cent of white arsenic.

Despite the numerous opportunities for arsenical poisoning in industries it is rare or, at any rate, is only rarely reported.

ARSENIURETTED HYDROGEN POISONING.—Industrial poisoning from arseniuretted hydrogen is caused mostly by inhalation of the gases developed by the action on one another of acids and metals which contain arsenic. Hydrogen gas as usually prepared for filling balloons gives occasion for poisoning.

In Breslau in 1902 five workmen became affected, of whom three died from inhalation of arseniuretted hydrogen gas in filling toy balloons.[1]

Further, use of hydrogen in lead burning may expose to risk, and also preparation of zinc chloride flux.

Of thirty-nine recorded cases of arseniuretted hydrogen poisoning twelve were chemists, eleven workers filling toy balloons, seven aniline workers, five lead smelters, three balloonists, and in one the origin could not be traced. Nineteen of these proved fatal within from three to twenty-four days.[2]

Cases are recorded (1) in the reduction of nitroso-methylaniline with zinc and hydrochloric acid; (2) in the preparation of zinc chloride from zinc ashes and hydrochloric acid; (3) from manufacture of zinc sulphate from crude sulphuric acid and zinc dust; (4) in spelter works in the refining of silver from the zinc crust with impure hydrochloric acid; and (5) in the formation room of accumulator factories.

The English factory inspectors’ report describes in 1906 occurrence of three cases in an electrolytic process for the recovery of copper in which the copper dissolved in sulphuric acid was deposited at the cathode, and hydrogen at the lead anode. In the 1907 report mention is made of two cases, one affecting a chemist separating bismuth from a solution of bismuth chloride in hydrochloric acid, and the other (which proved fatal) a man who had cleaned a vitriol tank.

The poisoning resulting from ferro-silicon is in part referable to development of arseniuretted hydrogen gas.

ANTIMONY

It seems doubtful if industrial poisoning can really be traced to antimony or its compounds; generally the arsenic present with the antimony is at fault. Erben[1] considers that industrial antimony poisoning occurs among workmen employed in smelting antimony alloys in making tartar emetic through inhalation of fumes of oxide of antimony.

A case is cited of a workman in Hamburg engaged in pulverising pure antimony who was attacked with vomiting which lasted for several days, and the inspector of factories noted epistaxis (nose bleeding) and vomiting as following on the crushing of antimony ore.

Compositors in addition to chronic lead poisoning may suffer, it is alleged, from chronic antimony poisoning, showing itself in diminution in the number of white blood corpuscles and marked eosinophilia. These changes in the blood could be brought about experimentally in rabbits. Antimony was found by the Marsh test in the stools of those affected.

IRON

_Pig iron_ is obtained by smelting iron ores in blast furnaces (fig. 29), through the upper opening of which charges of ore, limestone or similar material to act as a flux, and coke are fed in succession. The furnaces are worked continuously, using a blast of heated air; carbon monoxide is produced and effects the reduction of the ore to molten iron. The latter accumulates in the hearth and is covered with molten slag; this flows constantly away through an opening and is collected in slag bogies for removal, or is sometimes cooled in water.

The crude iron is tapped from time to time, and is led in a fluid condition into moulds called ‘pigs,’ in which it solidifies. Cast iron is occasionally used direct from the blast furnace for the purpose of making rough castings, but generally it is further refined before being used in a foundry by remelting with cast iron scrap in a cupola furnace.

_a_ Hearth; _b_ Bosh; _c_ Shaft; _d_ Gas uptake; _e_ Down-comer; _f_ Tuyères with water cooling arrangement; _g_ Blast pipes; _h_ Tapping hole; _k_ Supporting columns; _l_ Furnace bottom; _m_ Charging hopper; _n_ Bell with raising and lowering arrangement.]

_Wrought iron_ is made by treating pig iron in refinery and puddling furnaces; in these much of the carbon is removed as carbon monoxide, and from the puddling furnace the iron is obtained as a pasty mass which can be worked into bars, rods, or plates.

_Steel_ is made in various ways. The Acid Bessemer process consists in forcing compressed air in numerous small streams through molten cast iron, in iron vessels (converters) which are lined with ganister, a silicious sandstone. These can be rotated on trunnions. Basic Bessemer steel is made in similar converters by the Thomas-Gilchrist or basic process, which can be applied to pig irons containing phosphorus. The latter is removed by giving the converter a basic lining of calcined magnesium limestone mixed with tar.

In the _Martin_ process steel is obtained by melting together pig iron with steel scrap, wrought iron scrap, &c., on the hearth of a Siemens regenerative furnace with a silicious lining.

In iron smelting the most important danger is from _blast furnace gas_ rich in carbonic oxide. Sulphur dioxide, hydrocyanic acid, and arseniuretted hydrogen gas may possibly be present.

When work was carried out in blast furnaces with open tops the workers engaged in charging ran considerable risk. But as the blast furnace gas is rich in carbonic oxide and has high heating capacity these gases are now always led off and utilised; the charging point is closed by a cup (Parry’s cup and cone charger) and only opened from time to time mechanically, when the workers retire so far from the opening as to be unaffected by the escaping gas. The gas is led away (fig. 29) through a side opening into special gas mains, is subjected to a purifying process in order to rid it of flue dust, and then used to heat the blast, fire the boilers, or drive gas engines.

Severe blast furnace gas poisoning, however, does occur in entering the mains for cleaning purposes. Numerous cases of the kind are quoted in the section on Carbonic oxide poisoning.

The gases evolved on tapping and slag running can also act injuriously, and unpleasant emanations be given off in granulating the slag (by receiving the fluid slag in water).

In the puddling process much carbonic oxide is present. Other processes, however, can scarcely give rise to poisoning.

The _basic slag_ produced in the Thomas-Gilchrist process is a valuable manure on account of the phosphorus it contains; it is ground in edge runners, and then reduced to a very fine dust in mills and disintegrators. This dust has a corrosive action already referred to in the chapter on Phosphorus and Artificial Manures.

The poisoning caused by _ferro-silicon_ is of interest. Iron with high proportion of silicon has been made in recent years on a large scale for production of steel. Some 4000 tons of ferro-silicon are annually exported to Great Britain from France and Germany. It is made by melting together iron ore, quartz, coke, and lime (as flux) at very high temperature in electrical furnaces. The coke reduces the quartz and ore to silicon and metal with the production of ferro-silicon. Certain grades, namely those with about 50 per cent. silicon, have the property of decomposing or disintegrating into powder on exposure for any length of time to the air, with production of very poisonous gases containing phosphoretted and arseniuretted hydrogen. The iron and quartz often contain phosphates, which in presence of carbon and at the high temperature of the electrical furnace would no doubt be converted into phosphides combining with the lime to form calcium phosphide; similarly any arsenic present would yield calcium arsenide. These would be decomposed in presence of water and evolve phosphoretted and arseniuretted hydrogen gas. In addition to its poisonous properties it has also given rise to explosions.

[In January 1905 fifty steerage passengers were made seriously ill and eleven of them died. In 1907 five passengers died on a Swedish steamer as the result of poisonous gases given off from ferro-silicon, and more recently five lives were lost on the steamer _Aston_ carrying the material from Antwerp to Grimsby.[C] This accident led to full investigation of the subject by Dr. Copeman, F.R.S., one of the Medical Inspectors of the Local Government Board, Mr. S. R. Bennett, one of H.M. Inspectors of Factories, and Dr. Wilson Hake, Ph.D., F.I.C., in which the conclusions arrived at are summarised as follows:

1. Numerous accidents, fatal and otherwise, have been caused
within the last few years by the escape of poisonous and
explosive gases from consignments of ferro-silicon, which,
in every instance, have been found to consist of so-called
high-grade ferro-silicon, produced in the electric furnace.

2. These accidents, for the most part, have occurred during
transport of the ferro-silicon by water, whether in sea-going
vessels or in barges and canal-boats plying on inland waters.

3. These accidents have occurred in various countries and on
vessels of different nationalities, while the ferro-silicon
carried has, in almost every instance, been the product of a
different manufactory.

4. Ferro-silicon, especially of grades containing from 40 per
cent. to 60 per cent. of silicon, is invariably found to evolve
considerable quantities of phosphoretted hydrogen gas, and, in
less amount, of arseniuretted hydrogen, both of which are of a
highly poisonous nature. A certain amount of the gas evolved
is present, as such, in the alloy, being ‘occluded’ in minute
spaces with which its substance is often permeated.

5. As the result of careful investigation, it has been
shown that certain grades of ferro-silicon—notably such as
contain about 33 per cent., 50 per cent., and 60 per cent. of
silicon—even when manufactured from fairly pure constituents,
are both brittle and liable to disintegrate spontaneously, this
latter characteristic being apt to be specially marked in the
case of the 50 per cent. grade.

All these grades are commonly employed at the present time.

6. In the event of disintegration occurring, the amount of
surface exposed will, obviously, be greater than if the mass
were solid.

7. Evolution of poisonous gases is greatly increased by the
action of moisture, or of moist air, under the influence
of which phosphoretted hydrogen is generated from calcium
phosphide, which, in turn, is formed, in large part, at any
rate, from the calcium phosphate present in anthracite and
quartz, at the high temperature of the electric furnace. If
spontaneous disintegration of the alloy also occurs, much
larger quantities of gas would be given off from such friable
and unstable material, other conditions being equal. The
greater or less tendency of a given sample to evolve poisonous
gases, and even a rough estimate of their probable amount may
be arrived at by the use of test-papers prepared with silver
nitrate.

8. There is no evidence that low-grade ferro-silicon (10 to
15 per cent.), produced in the blast-furnace, has ever given
rise to accidents of similar character to those known to have
been caused by the high-grade electrically produced alloy.
Blast-furnace ferro-silicon does not evolve poisonous gases
even in presence of moisture.

9. As regards ferro-silicon produced in the electric furnace,
the evidence available goes to show that certain percentage
grades are practically quite innocuous. This statement applies
to grades of alloy of a silicon content up to and including
30 per cent., and probably also, though in considerably less
degree, to those of 70 per cent. and over.

10. In view of the fact that the use of ferro-silicon of grades
ranging between 30 per cent. and 70 per cent. apparently is
not essential in metallurgical operations, with the possible
exception of basic steel manufacture, it will be advisable that
the production of this alloy of grades ranging between these
percentages should be discontinued in the future.

11. The proprietors of iron and steel works making use
of ferro-silicon will assist in the protection of their
workpeople, and at the same time act for the public benefit by
restricting their orders to grades of this material, either
not exceeding 30 per cent., or of 70 per cent. and upwards,
according to the special nature of their requirements.

12. But as, pending international agreement on the question,
intermediate percentages of ferro-silicon will doubtless
continue to be manufactured and sold, the issue, by the Board
of Trade, of special regulations will be necessary in order to
obviate, so far as may be possible, chance of further accidents
during the transport of this substance.

_Inter alia_, these regulations should require a declaration
of the nature, percentage, date of manufacture, and place of
origin of any such consignment.

The suggested regulations are printed on p. 291.]

ZINC

Industrial poisoning from zinc is unknown. The chronic zinc poisoning among spelter workers described by Schlockow with nervous symptoms is undoubtedly to be attributed to lead.

COPPER: BRASS

_Occurrence of brass-founder’s ague._—Opinion is divided as to whether pure copper is poisonous or not. Lehmann has at any rate shown experimentally that as an industrial poison it is without importance.

Occurrence, however, of brass-founder’s ague is undoubtedly frequent. Although neither pure zinc nor pure copper give rise to poisoning, yet the pouring of brass (an alloy of zinc and copper) sets up a peculiar train of symptoms. As the symptoms are transient, and medical attendance is only very rarely sought after, knowledge of its frequency is difficult to obtain.

Sigel,[1] who has experimented on himself, believes that the symptoms result from inhalation of superheated zinc fumes. In large well-appointed brass casting shops (as in those of Zeiss in Jena) incidence is rare.

Lehmann[2] very recently has expressed his decided opinion that brass-founder’s ague is a zinc poisoning due to inhalation of zinc oxide and not zinc fumes. This conclusion he came to as the result of experiments on a workman predisposed to attacks of brass-founder’s ague. Lehmann’s surmise is that the symptoms are due to an auto-intoxication from absorption of dead epithelial cells lining the respiratory tract, the cells having been destroyed by inhalation of the zinc oxide. He found that he could produce typical symptoms in a worker by inhalation of the fumes given off in burning pure zinc.

_Metal pickling._—The object of metal dipping is to give metal objects, especially of brass (buckles, lamps, electric fittings, candlesticks, &c.), a clean or mat surface and is effected by dipping in baths of nitric, hydrochloric, or sulphuric acid. Generally after dipping in the dilute bath the articles go for one or two minutes into strong acid, from which injurious fumes, especially nitrous fumes, develop with occasionally fatal effect (see the chapter on Nitric Acid). Unfortunately, there are no references in the literature of the subject as to the frequency of such attacks.

Recovery of gold and silver has been already referred to in the chapters on Mercury, Lead, and Cyanogen.

Mention must be made of _argyria_. This is not poisoning in the proper sense of the word, as injury to health is hardly caused. Argyria results from absorption of small doses of silver salts which, excreted in the form of reduced metallic silver, give the skin a shiny black colour. Cases are most frequently seen in silverers of glass pearls who do the work by suction. Local argyria has been described by Lewin in silvering of mirrors and in photographers.

III. OCCURRENCE OF INDUSTRIAL POISONING IN VARIOUS INDUSTRIES

The most important facts have now been stated as to the occurrence of poisoning in industry, and there remain only a few gaps to fill in and to survey briefly the risks in certain important groups of industry.

TREATMENT OF STONE AND EARTHS

Lime Burning: Glass Industry

Lead poisoning in the ceramic industry (earthenware, porcelain, glass, polishing of precious stones, &c.) has been dealt with in detail in the chapter on Lead. There is further the possibility of chrome-ulceration, of arsenic poisoning, and conceivably also of manganese. Further, poisoning by _carbonic oxide_ and carbon dioxide may occur from the escape of furnace gases where hygienic conditions are bad. In charging lime kilns poisoning by carbonic oxide has occurred. The report of the Union of Chemical Industry in 1906 describes the case of a workman who was assisting in filling the kiln with limestone. As the furnace door was opened for the purpose gas escaped in such amount as to render him unconscious. He was picked up thirty minutes later, but efforts at resuscitation failed.

Carbonic oxide poisoning, again, may arise from the use of Siemens regenerative furnaces, especially glass furnaces: details are given in the chapter on Illuminating Gas.

_Hydrofluoric acid_ is present as an industrial poison in _glass etching_ (see Fluorine Compounds). Persons employed in this process suffer from inflammation of the respiratory tract and ulceration of the skin of the hands. I could not find any precise statement as to the frequency of the occurrence of such injuries. Use of sand-blasting to roughen the surface of glass has to some extent taken the place of etching by hydrofluoric acid.

TREATMENT OF ANIMAL PRODUCTS

In _tanning_ use of arsenic compounds for detaching the wool from skins and of gas lime for getting rid of hair may cause injury to health. With the latter there is possibility of the action of cyanogen compounds (see the chapters on Arsenic and Cyanogen).

PREPARATION OF VEGETABLE FOOD STUFFS AND THE LIKE

In _fermentation_ processes as in breweries and the sugar industry accumulations of carbonic acid gas occur, and suffocation from this source has been repeatedly described. Mention in this connection should be made of the use of salufer containing some 2 per cent. of silicofluoric acid as a preservative and antiseptic in beer brewing. In the _sulphuring_ of hops, wine, &c., the workers may run risk from the injurious action of sulphur dioxide. _Arsenic_ in the sulphuric acid used for the production of _dextrine_ may set up industrial poisoning. Poisoning from _ammonia_ gas can occur in _cold storage_ premises. Industrial poisoning from tobacco is not proved, but the injurious effect of the aroma and dust of tobacco—especially in women—in badly arranged tobacco factories is probable.

WOOD WORKING

_Injurious woods._—In recent literature there are several interesting references to injury to health from certain poisonous kinds of wood—skin affections in workers manipulating satinwood, and affections of the heart and general health in workers making shuttles of African boxwood. Details of these forms of poisoning are reported from England and Bavaria. The wood used for making the shuttles was West African boxwood (Gonioma Kamassi). It appears that the wood contains an alkaloidal poison which affects the heart’s action. The workers suffered from headache, feeling of sleepiness, lachrymation, coryza, difficulty of breathing, nausea, and weakness. Four workers had to give up the work because of the difficulty in breathing. Inquiry was made by Dr. John Hay of Liverpool in 1908 and by the medical inspector of factories in 1905. The following table shows the symptoms found:

+----------------------+-----------------------------------+
| | Persons Examined. |
| +-----------------+-----------------+
| Symptoms. | 1905. | 1907-1908. |
| +-------+---------+-------+---------+
| |Number.|Per cent.|Number.|Per Cent.|
| (1) | (2) | (3) | (4) | (5) |
+----------------------+-------+---------+-------+---------+
|Headache | 27 | 24·1 | 18 | 22·8 |
|Feeling of somnolence | 10 | 9·0 | 17 | 21·5 |
|Running of eyes | 13 | 11·6 | 9 | 11·3 |
|Running of nose | 28 | 25·0 | 20 | 28·0 |
|Breathing affected | 34 | 30·4 | 13 | 16·4 |
|Nausea or sickness | 13 | 11·6 | 3 | 3·8 |
|Faintness or weakness | 11 | 9·6 | 1 | 1·2 |
+----------------------+-------+---------+-------+---------+

The later inquiry shows considerable diminution in the amount of complaint as to respiratory trouble. This may have been due to the improved conditions of working, freely acknowledged by the men. Men were examined who had complained of the effects of the wood in 1905, and had continued uninterruptedly at the same kind of work during the interval without any obvious further injury to their health, although they preferred working on other woods.

East Indian boxwood had to be discarded in the shuttle trade owing to its irritant action on the eyes. Sabicu wood from Cuba was stated to give off ‘a snuffy dust under the machine and hand planes, the effect of which upon the worker is to cause a running at the eyes and nose, and a general feeling of cold in the head. The symptoms pass off in an hour or so after discontinuance of work.’ Reference was made in the report for 1906 to eczematous eruptions produced by so-called Borneo rosewood, a wood used owing to its brilliant colour and exquisite grain in fret-saw work. The Director of the Imperial Institute experimented with this wood, but failed to discover injurious properties in it. At the same time experiments with the wood and sawdust of East and West Indian satinwood were undertaken, but also without result.

From inquiries subsequently made it appeared that much confusion existed as to the designation ‘satinwood,’ as under this name were classed both East and West Indian satinwood and also satin walnut. The evidence was clear that East Indian satinwood was more irritating than West Indian. Satin walnut wood is apparently harmless. In the shipbuilding yards of East London, Glasgow, and Bristol affections of the skin were recognised, but susceptibility to the wood varied. One man asserted that merely laying a shaving on the back of his hand would produce a sore place. The injurious effects here seem to disappear quickly. Exhaust ventilation is applied, but there is a tendency to give up the use of the wood.

Isolated cases of illness have been ascribed to working teak and olive wood. In Sheffield the following are held to be irritating: ebony, magenta rosewood, West Indian boxwood, cocos wood. Some kinds of mahogany are said to affect the eyes and nose.

Use of methylated spirit in polishing furniture is said to lead to injury to health although not to set up actual poisoning. Lead poisoning can occur from the sand-papering of coats of paint applied to wood.

In impregnating wood with creosote and tar the effects on the skin noted in the chapter on Tar are observed.

TEXTILE INDUSTRY

In getting rid of the grease from animal wool carbon bisulphide or _benzine_ may be used.

The process of _carbonising_ in the production of shoddy may give rise to injury to health from acid fumes. Lead poisoning used to be caused by the knocking together of the leaden weights attached to the Jacquard looms. This is a thing of the past, as now iron weights are universal.

Opportunity for lead poisoning is given in the weighting of yarn—especially of silk with lead compounds.

In _bleaching_ use of chlorine and sulphur dioxide has to be borne in mind.

In _chemical cleaning_ poisoning by benzine may occur.

In _dyeing_ and _printing_ use of poisonous colours is lessening, as they have been supplanted by aniline colours. On occurrence of aniline poisoning in aniline black dyeing see the section on Aniline. Use of lead colours and of chromate of lead are dealt with in special sections.