may be due to a match being accidentally pulled from the pocket and falling to the floor where it is stepped on and ignited. In all plants in which explosives, volatile liquids, or inflammable substances are made or used, the clothing of all employees should be searched for matches, by authorized persons, at least twice a week, such search being made at irregular hours in order to prevent any warning being given. As the guilty person will usually deny his guilt, the causation of fires by smoking, carrying of matches or cigar lighters, or the possession of lenses, cannot always be definitely proved; hence, many firms which handle black powder, nitrostarch, trinitrotoluol, etc., seek to eliminate this danger by exercising the right to immediately discharge any employee detected with any of these articles in his possession. This discharging of employees for these violations should be made a mandatory rule of the Industrial Code because it was found that fires and explosions had occurred in various factories from the ignition of benzine vapor, flashlight.powder, methyl alcohol, and ethyl alcohol by such agencies as static sparks, electric fuse sparks, sparking motors, and sparks due to the nails in workmen's shoes striking on concrete floors, and it is reasonable to believe that the careless handling of matches, lenses, etc., could easily produce like results. To determine the extent of violations of the rules against carrying matches in plants where serious fire hazards were present (plants manufacturing wood alcohol, colors, etc.), the investigators would casually ask a workman here and there for a match, and, in many instances, the matches were immediately handed out, thus showing the little attention given to prohibitory notices regarding them.

All buildings in which such explosives as fulminate of mercury and trinitrotoluol are made or handled, should receive careful attention as to location, construction, and equipment; these buildings should be at least two hundred and fifty feet from each other, constructed of fire-resisting material, equipped with the necessary number of doors opening outward, and provided with floors covered with lead in such manner that there are no crevices.

In addition to the above, all buildings in which trinitrotoluol is handled or used should be equipped with sprinkler systems in

which an extinguishing agent is used, as well as with patent fire extinguishers, and the necessary water connections for fire hose. In all buildings in which the material handled or made presents a possible fire hazard from sparking of motors, fuses, electric bells, and electric switches, all these electrical devices must be placed outside of any room in which such hazard may be present.

Considerable heat is generated by the passing of sunlight through glass and it is believed that many barn fires, which are usually charged to tramps smoking in hay lofts, are really due to the action of the sun's rays passing through the window glass, or, through glass bottles or other glass receptacles placed on shelves or ledges, such glass acting as a lens. While the danger of fire from this source may seem remote, the State of New Jersey has recognized its possibility and prohibits the carrying of lenses by employees or others into any building in which dynamite, nitrocellulose, or trinitrotoluol is made or used.

In one instance in which a fire occurred in a factory in New York State engaged in the manufacture of dyes, it was found that the finished product, in the form of fine powder, was placed in open barrels along a wall and near the windows; the path of the fire was traced directly from these barrels to the other parts of the factory building and, as no reasonable cause could be found which would indicate contact with sparks or flame, it is within reason to believe that this fire may have been started by the action of the rays of the sun, passing through the window glass, on the powdered dye in the barrels.

Spontaneous combustion, or ignition, has been given as the cause of many fires in factories principally because no other reasonable cause could be found, and in most instances this conclusion has been perfectly correct.

When one considers the long list of substances which, by heat, friction, chemical combination of gases, action of light, or pressure, can be ignited, or cause other substances near them to burst into flame, it becomes apparent that not only men having a chemical training, but every factory proprietor, mercantile owner, superintendent, and foreman should have a full knowledge of the physical properties of and be fully acquainted with the list of

substances which should not be stored in the same room or closet, or near heated pipes, or in direct sunlight.

The oily rag, or piece of oily waste, usually found on the floor, shelves, or other places in engine rooms, which is used to wipe oil

FIG. 8 The victim of a color flash.

It may have been a vapor explosion, dust explosion or spontaneous ignition, the cause being questionable.

and dirt from machinery constitutes a fire hazard in any factory. but particularly in factories where there may be, either present or generated, hydrogen or carbon monoxide gases, or vapors of

ether, benzine, alcohol, benzol, chloroform, acetone, amyl alcohol, or amyl acetate. Investigators found instances in which two pieces of oil soaked waste lying close together on the floors of actories, but entirely away from fire, were smoldering; it is a well known fact that cotton waste moistened with oil and permitted to remain covered in a warm place for a time will have its temperature raised sufficiently to ignite it, and that a focused ray of sunlight passing through a window and reaching oily waste will readily generate sufficient heat to raise such oily waste to its kindling point.

Sodium peroxide, which is manufactured in two factories in the State of New York, must never be permitted to come into contact with any organic materials owing to its high oxidizing properties; during its manufacture it must be guarded against contact with furnace gases, through leaks in retorts, etc., because this will result in a chemical combination which can cause an explosion. Metallic sodium will decompose water with the generation of sufficient heat to ignite the liberated hydrogen gas and thereby produce an explosion.

In the manufacture of Prussian blue, the drying process is a danger point due to the possibility of overheating the drying device; instances of the drying material being aglow, from this cause, when the drier was opened were found during the investigation. Antimony and chlorine gas, brought into contact with each other, will ignite and produce a fire of their own accord. Dust, and vapors of alcohol, benzine, benzol, ether, and turpentine may readily be ignited by static sparks created by rapidly revolving belts, especially in dry cold weather, and result in both fire and explosion. Nitric or sulphuric acid, escaping from breakage or upsetting of carboys, coming in contact with excelsior, cotton rags, or wool will readily ignite these substances. The spon

taneous ignition of coal stored under certain conditions is such a familiar subject that nothing more need be said about it in this bulletin. Ammonia in contact with chlorine gas, alcohol in contact with permanganic acid, and the sudden warming of impure guncotton to a temperature of 186 C. will all produce spontaneous explosions.

Many other conditions, in which spontaneous combustion and explosions may take place, could be named, but an attempt has been made to confine this Bulletin to those substances which are actually manufactured or handled in the State of New York, and constitute common hazards; some substances are as dangerous, if not more so, than those mentioned, but as they are rarely, or never, used here, they need not be considered.

Spontaneous combustion is usually of a hidden and mysterious nature, occurring in places where men seldom enter or work; hence, the application of knowledge of chemical reactions produced or taking place when certain materials are brought together, this reaction sometimes being slow and sometimes sudden, is essential in every branch of the chemical industry.

According to Schwartz (Fire and Explosion Risks, pp. 70-71), in order to aid in the prevention of fires, the following materials should not be stored together indiscriminately:

Organic substances with nitric acid, carriers of oxygen, ozone, peracids, picrates, chlorates, liquid air, fulminates, fats, or oils. Lampblack or carbonaceous substances with fats, oils, sulphur, metallic sulphides, or carriers of oxygen.

Metals in powder, as bronzes, with damp substances, water, dusty materials, mineral acids, oil of turpentine, peracids, or flowers of sulphur.

Resins, turpentine, or ethereal oils with iodine, chlorine, mineral acids, carriers of oxygen, or dangerous liquids, probably the most dangerous of these being nitric and sulphuric acids.

Peracids with organic substances, sulphur, metallic powders, bronzes, carbon, or dangerous liquids (liquids, the vapors of which are inflammable and form explosive mixtures with air).

Carriers of oxygen, liquefied oxygen, or ozone with fulminates, chlorates, organic substances (coal, sugar, starch), picrates, bronzes, metallic powders, dangerous liquids (ether, acetone, or carbon disulphide), lampblack, resins, phosphorus, sulphur, nitric acid, hydrogen sulphide, or dusty substances (fibrous waste).

Dangerous liquids (ether, acetone, benzol) with carriers of oxygen, ozone, liquefied oxygen, oil of turpentine, ethereal oils, or peracids.