Chapter XXXI

INDIA-RUBBER: DANGERS INCIDENTAL TO THE USE OF
BISULPHIDE OF CARBON AND NAPHTHA

Indiarubber is used in the manufacture of waterproof garments, door-mats, toys for children, insulators of electric wires, tobacco pouches, etc. In the production of these articles large numbers of people find employment. During my visits to indiarubber works in Manchester and London I had several opportunities of observing some of the dangers incidental to the trade.

On entering a waterproof garment manufactory one encounters an extremely pungent vapour, which dries and heats the nose and throat, and is apt to make the eyes run water. This is the fume that comes from naphtha, which is used to dissolve the rubber and to form the dough that is spread as a thin layer by means of a roller machine upon the cloth about to be waterproofed. Both coal tar and mineral naphtha are employed. The vapour of naphtha is extremely irritating, and can be detected over the whole of the factory. The colour of the waterproofed material depends upon the pigment that is employed. If, for example, black is wanted, all that has to be added to the dough, composed of indiarubber and naphtha, is lamp black. The men who feed the roller machines, and who regulate the distribution of the dough upon the cloth, are constantly breathing the irritating atmosphere, but I did not find any special complaint in regard to it from them. It is the girls who work in the overheated and often overcrowded rooms of the factory that suffer most. They are usually very anæmic and complain much of headache. So saturated are they with the fumes of naphtha that even after they have left the factory they still feel the taste of naphtha in their food. In the workrooms these girls are employed rolling and pressing the garments; joining the seams, etc., by rubber dissolved in naphtha. On a winter’s night, when the gas is full ablaze, the air of the workroom is extremely pungent, so that girls are often obliged to leave the room and go into the open air for a short period. The fumes of naphtha are more unpleasant than really dangerous; still there is no doubt that the constant inhalation of these fumes during working hours and the distaste for food thereby created cannot but in time undermine the health of the female worker, and render her more or less unfit for duty.

The dangerous process in the manufacture of indiarubber goods is not that in which naphtha is used, but _bisulphide of carbon_. In order to render rubber goods capable of withstanding alternations of heat and cold, and of retaining their elasticity in all kinds of weather, they must be _vulcanised_. The vulcanising agent is either the common flowers of sulphur or a compound of sulphur. When 50 to 60 per cent. of sulphur is added to rubber there is obtained a very hard product known as _ebonite_. Considerable care has to be taken in using sulphur. If, for example, too much sulphur is added to rubber, the goods become hard; 5 per cent. gives good elasticity. There are various ways of bringing indiarubber goods under the influence of sulphur. It may be done in the primary mixing of the dough, so that all that is subsequently required in the treatment of the waterproofed materials is exposure to a great heat, say 260° F. in a closed oven. Another method is to hang up non-vulcanised waterproofed goods for several hours in a hot stove in which there is a basin containing chloride of sulphur heated over a flame. These processes can scarcely be called dangerous, for they are conducted in closed chambers. The real danger lies in using as the vulcanising agent bisulphide of carbon, to which is often added a small quantity of chloride of sulphur. The bisulphide of carbon has an extremely offensive odour: it is very volatile and highly inflammable, but it is an excellent solvent for caoutchouc. To vulcanise indiarubber goods by means of bisulphide of carbon, the materials are passed through a solution containing about one thousand parts of bisulphide of carbon and from two to ten of chloride of sulphur. The indiarubber is dissolved by the carbon bisulphide and becomes incorporated with the sulphur given up by the chloride.

It is difficult to prevent the nauseating, offensive, and repellent vapour given off by carbon bisulphide penetrating the atmosphere of a workroom even when the room is provided with fans. Fortunately, in some respects, the work is carried on in the top storey of the factory. Here the long webs of cloth coated with indiarubber are vulcanised by being passed through a trough of bisulphide of carbon placed in front of rollers. Escaping at the distal end of the machine the cloth is afterwards hung up to dry. All the time the men are at work in this room they are exposed to the vapour of the bisulphide. Inhalation of the vapour is liable to induce a subacute inflammatory condition of the nerves of the limbs known as _peripheral neuritis_, in consequence of which men lose the power in their arms and legs. Some of the men whom I examined had been paralysed in their lower extremities, had been off work for several months, and had only slowly regained the use of their limbs. Occasionally men may work as long as three or four years in the bisulphide department without becoming paralysed. Before actually losing the power in their legs the men suffer from inco-ordination; they stagger when walking. The workmen complain of the carbon bisulphide vapour making them drowsy and of their sleep being heavy. After working for a few hours in the vulcanising department, they feel tired and sleepy. Thick or foggy weather rather tends to favour the development of these unpleasant symptoms.

The pernicious effects of bisulphide of carbon are by no means confined to the men. The women and girls who dip very fine indiarubber goods--for example, children’s balloons, tobacco pouches, etc.--into the bisulphide, suffer even more severely than the men. The poisoning shows itself under two forms. In one the symptoms which are slowly developed are dizziness, headache, vomiting, lassitude, and not infrequently paralysis of the arms or legs. Many of the female workers complain of tasting the nauseous bisulphide in their food. The appetite thus becomes impaired. In the other form of poisoning, which may be spoken of as acute, the individual is really intoxicated. Girls have told me that on leaving the factory at night they have simply staggered home, they have even fallen as if drunk, or at the end of a day’s work they have had a splitting headache, and on reaching home have sat down, tired out, and fallen asleep before touching their evening meal. This sleep is heavy and non-refreshing. In the morning they drag themselves to the factory feeling ill and headachy, and, like people who are accustomed to the intemperate use of alcohol, they only get relief and recover their nervous equilibrium by renewed inhalation of the vapour of the bisulphide of carbon. Sad as this state of things is, it is nothing to the extremely violent maniacal condition into which some of the workers, both male and female, are known to have been thrown. Some of them have become the victims of acute insanity, and in their frenzy have precipitated themselves from the top rooms of the factory to the ground. In consequence of bisulphide of carbon being extremely explosive, vulcanisation by means of it has generally to be carried on in rooms, one side of which is perfectly open. This open front is usually protected by iron bars.

Bisulphide of carbon, in addition to causing paralysis of the limbs and an exalted condition of the brain, induces a temporary form of amblyopia, or blindness. Women often suffer from excessive menstruation, and, if pregnant, they may abort. Girls sometimes become hysterical and excited. This form of _toxic hysteria_, like that in plumbism, often masks a deeper form of bisulphide of carbon poisoning. The individual becomes extremely loquacious; she shouts or sings, becomes very irritable, and may, when in this mood, perpetrate acts that are beyond her control and even beyond her consciousness. Just as in some people, after the excitement of alcoholic intoxication has passed off, there comes a stage of depression, physical and mental, so too after intoxication by bisulphide of carbon there is a period marked by great weakness of mind and body. Prolonged exposure to the vapour of bisulphide induces an enfeeblement of the intelligence that recalls the mental weakness of chronic alcoholic inebriety.

In addition to the risks from naphtha and bisulphide of carbon, indiarubber workers are said to be liable to consumption. Dr Philip of Edinburgh states that within a period of eight years he had under his care in the Hospital for Consumption 70 indiarubber workers, and that 85 per cent. of these suffered from respiratory diseases, the bulk of which was phthisis. His experience as to pulmonary phthisis has not been altogether confirmed by that of medical men elsewhere.

_Prevention of Poisoning._--Ventilation of the workrooms is of the first importance. This cannot be secured by open windows alone. Owing to the inflammability of carbon bisulphide no fires and no naked lights are allowed in the workroom. The workpeople complain, therefore, of the cold, and as a consequence cannot but have their vital resistance reduced thereby. The air of this particular part of the factory is redolent of the offensive odour coming from the open troughs and basins. As carbon bisulphide is heavier than the ordinary atmosphere, the artificial means of ventilation that are required are such as shall draw the air of the workroom downwards away from the worker. No young person should be allowed to work in the vulcanisation of indiarubber by means of carbon bisulphide, nor should any adult be allowed to work more than five hours a day--two and a half at a stretch--separated by at least an hour’s interval, which should be spent in the open air, if possible, and away from the factory.

This is a kind of work in which there ought to be alternation of employment. All receptacles containing carbon bisulphide when not in use should be covered. The machines should be provided with down-draught suction fans. During the drying of the vulcanised waterproof goods no person should be allowed to enter the room where these products are hanging unless on business that is absolutely necessary. Naphtha receptacles should, when not in use, be kept covered. No food should be eaten in the bisulphide department, and it should be discouraged also where naphtha is used. Girls say that they sometimes can only eat food in the workrooms, because they do not taste the naphtha there. In the open air the food tastes as though it contained naphtha. Workers in the bisulphide process should be medically examined once a month, and the slightest indication of commencing paralysis or other nervous manifestation should be followed by suspension from work. Five hundred cubic feet of air space should be allowed to each worker.

Poisoning by bisulphide of carbon in its minor form generally disappears on removing the individual from his employment. By many of the workers, particularly girls who are extremely poor and ill-fed, suspension from work would be keenly felt, for to them the loss of the weekly wage is a serious matter. When peripheral neuritis has been induced and causes paralysis, recovery is usually tedious. The patient under these circumstances should be taken to a hospital, where under the influence of good food, rest, electricity, and tonic treatment, health will in most instances be regained.

In the _Allgm. Medic. Central Zeitung_, 22nd December 1900, Lazarus, a surgeon-dentist, draws attention to a new malady to which workers in gutta-percha are liable. In one year he observed twenty cases of dental caries and necrosis of the jawbone not unlike that met with in lucifer matchmakers, and known as phosphorus necrosis. Those workers, who on entering the factory were already the subjects of decayed teeth and carious stumps, are the most predisposed. With the exception of a young woman, aged 19 years, and who had worked in the factory for only two years all the other females who suffered were from 25 to 35 years of age. While Lazarus recommends a dental examination of the teeth of all the workers before entering a gutta-percha factory, he offers no suggestion as to the probable causes of the necrosis of the jaw in the patients who came under his care for treatment.

THOMAS OLIVER.