ANSI E1.29-2009 pdf download Product Safety Standard for Theatrical Fog Generators That Create Aerosols of Water, Aqueous Solutions of Glycol or Glycerin, or Highly Refined Alkane Mineral Oil
2.2.6.1 Fog generators that use glycol, glycerin, or white mineral oil The hygiene of the aerosols produced by fog generators that produce aerosols of glycol, glycerin, or white mineral oil (highly refined alkane oil), or any combination of these chemicals, with or without water, shall be evaluated by the tests described in clauses 2.2.6.1 .1 through 2.2.6.1 .3.
2.2.6.1.1 The fog generator and fluid shall be evaluated as a possible vector for harmful micro- organisms. Forty covered Petri dishes with sterile nutrient agar shall be distributed in 20 sampling pairs about a testing room. One of each of the pairs shall be uncovered and exposed to the air in the room for 20 minutes and then covered. Immediately following this, the fog generator being evaluated shall be used according to its user operating instructions to fog the same room to a concentration of twice the glycol and glycerin peak exposure limits stated in the current edition of ANSI E1 .5, or to 50 mg/m 3 for highly refined alkane mineral oil, as appropriate for the fog fluid used with the machine. The fog level shall be maintained for 20 minutes while the un-exposed Petri dishes of each of the pairs are uncovered and exposed to the fog for 20 minutes and then covered. All 40 Petri dishes shall be allowed to incubate at 20 degrees C for three days and then the Petri dishes shall be evaluated for bacteria and fungus growth. The Petri dishes exposed to the fog shall not have significantly larger fungus or bacterial colonies than the Petri dishes not exposed to the fog. The null hypothesis shall be that there is no significant difference between the two means of the two sets of samples. The null hypothesis shall not be rejected if the mean for the fog exposed samples is below the mean for the non-fog exposed samples, or if the mean is higher but the probability of the difference being attributable to chance is above 0.9. The fog generator produces an aerosol that is acceptable if the null hypothesis is not rejected. The fog generator and fog fluid combination shall be considered unlikely to be a vector of harmful micro-organisms if the null hypothesis is not rejected.