For the foregoing reasons given, treatment of the insulating 
material does not seem very important. Nevertheless, it is possible by- 
suitable treatment to increase the resistance of planer shavings and 
sawdust to fire, decay, and insects. The following treatments are 
suggested for the benefit of those who may be willing to undergo the ex- 
pense and inconvenience of treatment for the additional insurance of 
satisfactory performance that treatment will provide. It is not known 
that these treatments will have any effect on rats and mice, but they 
include chemicals known to be highly effective against decay, insects, 
and fire. 
Treatment A 
For Decay and Insects 
To each 100 pounds of air-dry sawdust or planer shavings add 3 
pounds of sodium fluoride. The addition may be made by spreading the 
sawdust on a floor, spreading the sodium fluoride over it, and then mix- 
ing the two together by repeated shoveling and stirring. A concrete 
mixer could be used if available. Sodium fluoride is a fine white 
powder that is poisonous to human and animal life. Care should be taken 
to avoid breathing or swallowing the dust. Since sodium fluoride resem- 
bles sugar, table salt, and baking soda so closely that it may be mis- 
taken for them, it is best not to have any left over after the treating 
job is done. Dampening the sawdust with water before spreading the 
fluoride on it should avoid dusting troubles. A still better method of 
application is to dissolve the sodium fluoride in 12 to 15 gallons of 
hot water and mix the water with the sawdust. 
After the chemical is mixed with the wood, the mixture should be 
dried very thoroughly before putting it into the walls of a building. 
Treatment B 
For Fireproofing 
With 100 pounds of dry sawdust mix thoroughly (by sprinkling 
and stirring) a water solution containing 5 pounds of monoammonium 
phosphate and 5 pounds of borax (about 12 to 15 gallons of water should 
be sufficient). If inseat and decay resistance are desired as well as 
fireproofing, both Treatment A and Treatment B can be given at the 
same time, dissolving all the chemicals in the same water. 
No specific information as to cost can be given, for labor and 
chemicals costs vary widely in different localities. Both transporta- 
tion charges and quantity purchased have an important bearing on the 
cost of the chemicals. Current wholesale quotations in trade journals 
R1092 _3_ 
