Disinfection of hatching eggs by formaldehyde fumigation - a review

Losses due to microbial contamination of hatching eggs in the poultry industry can run into millions of Euros. Fumigation with formaldehyde gas is an effective way of disinfection before and during incubation as well as near hatching. The present paper is a review of the literature on the conditions and effects of formaldehyde fumigation. In summary: for disinfection against Salmonella species, nest clean eggs should be fumigated prior to incubation at room temperature (25 C) and ambient humidity for at least 20 minutes with a minimum concentration of 600 mg formaldehyde gas per m(3) (i.e. 10 g paraformaldehyde or 45 ml of 40% formalin and 30 g KMnO4). Fumigation under these conditions kills 99.8% of microorganisms on the shell surface and is not associated with increased embryonic mortality. Fumigation should not be performed during the first 9 days of incubation. Fumigation at pipping may damage the respiratory system of chicks and have adverse effects on the health and production performance. In addition, formaldehyde is also hazardous to human health.