set to be maintained in all workrooms because certain conditions and processes will require a variation from this standard. This is well shown by the following: The packing of certain chemicals must be done in rooms where the temperature is high and the humidity low in order to avoid the deleterious action of moisture on the material handled; and certain classes of hard labor may be more advantageously and efficiently performed at lower temperatures than the usually advised standard which fixes a minimum temperature of 62° F. and a maximum temperature of 72° F. in rooms in which ordinary labor is performed (See Page 18, Welfare Work, Series No. 4, U. S. Government, July, 1918).

VENTILATION

One of the most important methods of eliminating fire and health hazards from any industry is the provision of a suitable and adequate system of ventilation to properly remove dust, gases, vapors, and fumes arising in the various processes used in the particular industry; this system may be local, general, or a combination of both.

Medical inspectors, connected with the investigation, definitely traced the cause of many cases of occupational poisoning to the lack of adequate ventilation of factory workrooms, the employees in such rooms being compelled to constantly inhale deleterious materials arising from machines, or mixing and packing processes; continued inhalation of dust, gases, vapors, and fumes which arise from such barrels, pipes, kettles, or pans results in a lowering of the vital resistance of the body with the production of many cases of illness, and some deaths. Two notable examples of death occurring from such causes are the following:

1. A firm engaged in the manufacture of alcohol from molasses has the molasses brought to its plant in barges from which it is pumped into tanks. A man working at a valve in the bottom of one of these barges was rendered unconscious and removed to a hospital where he died two hours later, the cause of death being given as "poisoning by gas of unknown character." Investigation of this case proved that the fermentation of the slight quantity of molasses adhering to the sides and bottom of the barge had resulted in the formation of a blanket of practically pure carbon

dioxide into which the man had fallen when he entered the barge to make the necessary repairs. Recommendation was made that all such barges be ventilated by the use of a heavy blast of compressed air before permitting workmen to enter them and has entirely eliminated this hazard.

2. A firm was engaged in the manufacture of metanitraniline (MNA), khaki dye, by a reduction process which resulted in the formation of dinitrobenzol during the course of the operation. Two plumbers were at work in the plant when a leak developed in one of the tanks; one of the plumbers, absolutely ignorant of the dangerous nature of this material, was sent into the tank to make the necessary repairs. After working in the tank for a short time, he came out and complained of feeling badly, his lips and face being slightly blue (cyanosis), but recovered sufficiently to start for home on a trolley car; he became seriously ill on the car and was removed to a hospital where he died about six hours later, the cause of death being given as "traumatic pneumonia due to the effects of a gas of unknown nature." Investigation proved absolutely that death was due to dinitrobenzol poisoning. The firm ceased operation, consequently nothing could be done to prevent a recurrence of such accident.

Various sections of the Labor Law and rules of the Industrial Code of the State of New York are very complete and comprehensive in their requirements for ventilation in certain specific processes, but regardless of these sections and rules and the orders. issued thereunder, proper systems and devices for ventilation have not always been provided to deal effectively with the matters in question; some manufacturers seem to think that any tinsmith can devise and install a suitable ventilating system, and that such system should be accepted as a full compliance with a specific order even when it has been demonstrated that such a system is worse than useless for the purpose sought to be attained.

Upward ventilation, by natural or artificial means, should be used for the removal of coal gas, ammonia, hydrocyanic acid, carbon monoxide, steam, fumes of methyl alcohol, nitric oxide, and hydrochloric acid, and the vapors which readily arise from vessels containing lead, arsenic, antimony, or zinc when same are heated to a certain degree, all of these materials being easily

handled by means of a suitable hood placed over the vessel containing them. When fumes or vapors of inflammable liquids, as methyl alcohol, amyl acetate, benzine, or ether, are to be removed by exhaust systems, belt-driven fans with copper or brass blades must be used; under no circumstances should there be used motordriven fans in which the motor or wiring system is in the direct path of the material to be removed.

Chromate of lead, barium sulphate, Paris green, silica, hydrated carbonate of lead, and most pigments and salts which present a dust hazard are raised only with difficulty, but may be very effectively dealt with by means of an exhaust system having a downward suction, this method being especially applicable to box, keg, or barrel filling. Hoods over machines, mills, or parts of machines should not be of a rigid type, but should be so constructed as to be readily raised, lowered, or otherwise adjusted.

The necessity for the proper ventilation of pits, tunnels, and store-rooms, which are often overlooked because seldom used, is well illustrated by the following example: Three men were sent into a pit and tunnel to make repairs on a pipe-line and valve contained therein; after disconnecting the valve, which left the pipeline open, they went out to their lunch. During their absence, the tunnel became partly filled with the fumes of benzol which escaped from the open pipe, this collection of fumes remaining in the tunnel because of the lack of suitable ventilation. Upon re-entering the tunnel, the men only worked for a brief period of time when two of them fell to the floor unconscious while the third one was barely able to get out of the tunnel and summon help; when this help arrived, the two men were dead, the third man owing his escape from a like fate to the fact that he had discovered the condition and had quickly reached the open air.

The piping of all volatile liquids from vats to pans, or other containers or machines, not only aids greatly in the elimination of a possible fire hazard, but results in a great saving of both time and material to the manufacturer. When filling barrels or tanks with volatile liquids, the escape into the workrooms of the fumes of such liquids, with the air which is displaced from the receptacle, may be readily prevented by providing a suitable relief pipe from the barrel or tank to the outer air; this will remove the

necessity for providing a general ventilating system which is usually costly especially in cold weather when fuel and power are important items of expense.

The proper repair of brick walls of furnaces, to prevent the escape of harmful gases into workrooms, is a more sensible and economical method of keeping the workroom air in a safe and desirable condition than the installation of a general ventilating system to modify the effects of such escaped gases by the dilution method.

Louvred monitors, or skylights provided with monitors, furnish a fairly effective means for the removal of smoke and heat from workrooms, but these devices can be rendered more effective by constructing them in such manner that the louvres can be readily opened and closed. During the cold months, when the outdoor temperature is low and wind pressure is high, the side against which the wind blows should be closed and the opposite side opened, thus making the force of the wind current serve as an aspirating medium to withdraw the heat and smoke from the building; if both sides are open, the wind pressure and cold air form a blanket which deflects and forces downward the naturally rising column of warm air, creates unpleasant drafts, and sweeps the smoke about the workrooms. The successful application of these devices has been demonstrated in a number of factories, particularly at Niagara Falls.

A very important matter which must be carefully considered is the provision of forced ventilation for drying ovens and drying rooms, this importance being due to the fact that the indrawn air must pass through a fan, then through a heater containing coils of pipe in which steam is circulating at various pressures, and, finally, into the drier or dry room. The temperature of the steam pipes in the heaters varies according to the steam pressure carried (228° F. for 5 lbs., 256° F. for 15 lbs., and 267° F. for 25 lbs. pressure). If the intake, or fan inlet, is so located that the air is drawn from a factory room, this air may contain dust which is quickly decomposed on contact with a certain degree of heat, and there will be created a hazard of fire and explosion, the latter of which may be of sufficient violence to destroy not only the drying device, but the entire building in which such device is contained.

Explosions of drying devices are known to have been produced by the ignition of organic colors, by friction or spark ignition, in the piping system of such device.

These are but a few of the many actual conditions met with in ordinary practice; each factory, or process, presents its own individual problem which may be solved by careful study, and result in the saving of considerable material and the elimination, or at least the reduction, of risk to both the plant and the employee.

ACCIDENTS AND OCCUPATIONAL DISEASES

Employees in factories engaged in the manufacture or compounding of chemicals are subjected to the danger of accidents from the same general causes as the workmen in other classes of manufacturing, these including injuries due to contact with falling objects, wounds and contusions from the handling of sharp or heavy materials, falls from ladders, wounds inflicted by tools and machines, and falls on slippery or uneven floors. In addition to the above, owing to the nature of the material handled, they are subjected to the danger of burns from acids or molten metal, the corrosive effect on the body tissues of caustic alkalies, alkaline earths, and chromium salts, and the poisonous effects of the inhalation of certain dusts, gases, fumes, and vapors. The irritant effects of sulphurous oxide, formaldehyde, sublimed sulphur, and the vapors of both nitric and sulphuric acids are too well known, through experience, to require further description. The pleasant odor of some of the poisonous vapors, as hydrocyanic acid, nitrobenzol, and methyl alcohol, is misleading to many workmen who only associate danger with an unpleasant odor and a quickly irritant effect; carbon monoxide has no odor, but is extremely deadly in its action.

One important fact brought out by this investigation is the refutation of the statement made by many writers, both American and English, that the toxic effects of trinitrotoluol (TNT) are due solely to the absorption of the finished product through the skin, or to the inhalation of the material in dust form; careful investigation proved that the majority of cases of illness from this substance were due to the inhalation of the fumes generated through the nitration of the toluol, the fumes of the first nitra