Practical Lessons on Spontaneous Combustion
The National Cash Register Company, of Dayton, O., has been giving demonstrations of spontaneous combustion for the benefit of its employees, as the result of a fire that occurred at the factory two months ago. The fire started in a bin where oily rags had been carelessly thrown. On one rag, it is believed, there was a little linseed oil. Drying of this oil, under certain conditions, is likely to start a fire. In order to show the employees the danger of allowing waste paper of any kind to accumulate, it was decided to demonstrate just how fires may be started without the application of a match or spark of any kind. A large tin box, from which one side had been removed, was placed in the hall window of the safety office. In this each morning are placed three rags, saturated with linseed oil and loosely confined in a dry rag to hold the heat. A few hours later the rags become a smoldering mass, ready to burst into flames. The explanation is that linseed oil is fast-drying. When finely divided on a cotton cloth a large surface of the oil is exposed to the air. Large quantities of oxygen are absorbed and heat is produced. The outside cloth conserves this heat. Finally the temperature becomes so high that the cloth burns. Hundreds of fires in various parts of the countrv have been started from such causes. Soot, linen, paper, cotton or woolen stuffs, when soaked with relatively small qufmtities of oils and exposed to limited access of air, take fire. Members of the National Cash Register Company’s health and safety committee recently investigated a fire discovered in a floor mop. The mop had been used to polish floors and was soaked in a fastdrving oil. Spontaneous combustion resulted. On another occasion at the company’s plant a fire was discovered in a charcoal bin. Charcoal dust, when slightly moistened, absorbs oxygen so rapidly that it burns. Steel and iron dust act in a similar way. The only safe rule to follow, the safety committee points out, is to keep all workshops clean and to refuse to allow rubbish or waste materials to accumulate. In Germany, where the fire prevention laws are most strictly enforced, the yearly per capita loss due to fires has been reduced to 20 cents. In the United States it is $2.55.