VEGETABLE AND FRUIT DEHYDRATION 141 



or soap, are not conducive to habits of cleanliness on the part of the 

 employees. Some of the best food plants in the country have their 

 washing facilities outside the rest rooms and the toilet room. The 

 employees must wash their hands where they can be seen by the super- 

 visor and the other employees in the plant. No one is permitted to go 

 back to his work unless he has washed his hands in that place. Hot 

 water, sanitary soap dispensers, and individual towels are provided. 



CONTROL OF INSECTS AND MITES 



Food manufacturing or processing "plants, including dehydration 

 plants, have the almost universal problem of insect and mite control. 

 The most effective means of preventing the access of such pests to 

 both the raw and finished materials is by the use of tight construction, 

 ratproofing, screens, and thorough sanitation. Unceasing vigilance is 

 necessary in removing the waste food materials upon which these pests 

 thrive. There should be regular and thorough inspection of the 

 premises and sampling of the products. Scalding water or vapor heat 

 in the form or live steam will kill all forms of insect life on direct 

 exposure. 



Fumigation 



A common method used in the control and extermination of insects 

 and mites is fumigation. It can be used to treat suspected products, 

 to check known infestations, and to clean out infestations and the 

 premises housing them. It is especially suitable for areas that can 

 be tightly enclosed. Fumigation is quick and effective and if properly 

 handled leaves no complicating after effects. It should be done by 

 trained or experienced personnel, with proper equipment, and at the 

 right time and temperature. The chemical to be used is determined 

 by the product and insects to be treated, and by the storage conditions 

 under which the treatment is to be made. The absorption and adsorp- 

 tion of the gases by the infested materials must be considered. After 

 treatment, the product must be properly aerated to allow the escape 

 of contaminating gases. 



Specially constructed, tight, ventilated fumigation rooms are 

 extremely useful in treating sacked and packaged material. Steel 

 vacuum fumigators are up-to-date devices for the treatment of 

 insect-infested products. Some of these are large enough to enclose 

 one or more freight boxcars at a single treatment. If possible, all 

 iumigants should be applied from the exterior. Gas masks equipped 

 with an unsaturated canister of proper type for the fumigant used 

 should be worn when handling or applying toxic chemicals. _ All 

 iumigants which are effective in killing insects are also toxic to 

 humans. Some gases, such as hydrocyanic acid gas, methyl bromide, 

 and others, are extremely dangerous and should be used only under 

 expert supervision. The correct length of exposure varies with the 

 concentration of the gas and the temperature. The temperature for 

 the best results is usually 70° F. or higher. 



Sprays 



A. spray composed chiefly of 10 to 15 percent oil emulsion, in which 

 tche viscosity of the oil is 90 or above, combined with an emulsifying 

 agent, is of great value in disinfecting empty bins. Water-white 



