2. Materials and methods
2.1. Test chemicals
Formalin (commercial grade) for the flow rate evaluation and efficacy tests was
obtained from Argent Chemical Company, Redmond, WA. A reagent grade formulation
used to prepare analytical standards was acquired from Sigma Chemical Company, St.
Louis, MO. Both formulations contained 37% formaldehyde gas dissolved in water with
lo-15% methonal added for stabilization. Hydrogen peroxide (technical grade) was
obtained from Eka Nobel, Marietta, GA, and contained 35% active ingredient. Treatment
concentrations were based on active ingredient. Sodium chloride (food-grade and
uniodized) was acquired from Morton International Inc., Chicago, IL.