The best sanitization out door and the cheapest one is a 5% solution of Sodium Hypochlorite solution. WHO and CDC (USA) recommendation are for Sodium Hypochlorite only and not any source of chlorine, like bleaching powder, TCCA or any other chemicals.
This can be used through a spraying bottle, spraying pumps, knapsack sprayers or sprayers commonly used for Agricultural purposes. A rechargeable knapsack sprayer is an inexpensive solution and popular for use in large outdoor spaces, godowns, schools etc.
The preferred hand sanitizer is alcohol based according to WHO recommendations. Alcohol based sanitizer should have a minimum of 75% Alcohol, which may be ethanol or Isopropyl Alcholo with less than 1% Glycerin (Glycerol, perfume etc. and distilled water/ demineralized or deionized water added as required.
Since this formulation is relatively expensive, it is advisable to use a fogging machine, which atomized the liquid and emits in the form of a mist. It is a great money saver.
Just two days ago, US FDA has issued warning for 9 brands of hand sanitizers. The reason among others is use of Methanol instead of Ethanol. Methanol is poisonous that causes many deaths through spurious liquor in which methanol has been added instead of Ethanol.
Issued in Public Interest by Society for Andaman & Nicobar Ecology