Studies on Evaporation of Hydrazine and Procedures for Cleanup of Small Spills

The evaporation rates of hydrazine (N2H4) from pools of the neat fuel and from aqueous solutions were measured under various environmental conditions. Hydrazine continues to evaporate for long periods of time (several days) even from solutions as dilute as 25-percent N2H4. Solutions of hydrazine appear to absorb carbon dioxide from the atmosphere. Carbon dioxide gas also suppresses evaporation of hydrazine from concrete surfaces. Procedures are outlined for cleanup and decontamination of small spills of hydrazine in the flightline area. Calcium hypochlorite (HTH), sodium hypochlorite solution (household bleach), and hydrogen peroxide with copper catalyst were evaluated for use as possible oxidants to treat dilute hydrazine solutions. Although all three give satisfactory results, either HTH or household bleach is recommended because of availability and ease of use.