RESEARCH SUMMARY 



THE AUTHOR 



Treated ponderosa pine needle and aspen excelsior fuel 

 beds were burned to quantify the fire-retarding capabilities 

 of five samples of monoammonium phosphates. The 

 samples were the same except for their manufacturing 

 processes, which could cause chemical impurities that 

 may decrease combustion-retarding effectiveness. Treat- 

 ment levels were normalized by converting to phosphate 

 equivalents when comparing effectiveness. To obtain 

 about equal penetration, approximately 0.26 gal (1 liter) of 

 a solution containing one of the chemicals was applied to 

 each bed. Different chemical treatment levels were 

 obtained by varying the solution concentrations. Solutions 

 were sprayed onto the fuel beds from a fan-type nozzle, 

 and after drying completely, the fuel was burned in a 

 5-mi/h (8-km/h) wind at 90° F (32.2° C) and 20 percent rela- 

 tive humidity. Analysis of covariance and percent 

 reduction in combustion rates were methods used to 

 compare levels of effectiveness. Test results indicate no 

 significant differences between the combustion-retarding 

 abilities of the five monoammonium phosphates, and all 

 proved to be as effective as standard diammonium phos- 

 phate when compared at equivalent phosphorous applica- 

 tion levels. 



AYLMER D. BLAKELY received his B.S. degree in forestry 

 in 1960, and his M.S. degree in forestry in 1970 from the 

 University of Montana. In 1967, he joined the Inter- 

 mountain Station's Northern Forest Fire Laboratory in 

 Missoula, Mont., where he currently works in fire retardent 

 chemical and delivery systems research in the Fire 

 Control Technology Research Work Unit. 



The use of trade, firm, or corporation names in this 

 publication is for the information and convenience of 

 the reader. Such use does not constitute an official 

 endorsement or approval by the U.S. Department of 

 Agriculture of any product or service to the exclusion 

 of others that may be suitable. 



