Treatment of discarded blood units: Disinfection with hypochlorite / formalin versus steam sterilization.

ABSTRACT

Blood bank regulations and bio medical waste rules of India advocate disinfection of contaminated blood units. Incineration is not recommended due to poly-vinyl chloride (PVC) content of blood bags. This study was designed to evaluate the efficacy of chemical disinfection of blood units deliberately contaminated with Staphylococcus aureus and E. coli with 1 and 6 % hypochlorite, 10% formalin and 33% formaldehyde and autoclaving of blood units contaminated with the above mentioned vegetative forms and B. stearothermophilus spores. Only 33 % formaldehyde could bring about 5 log reduction of bacteria but it is highly irritating and toxic. Autoclaving at 15 lbs pressure for 2 hours uniformly inactivated the vegetative forms and B. stearothermophilus spores. Thus, autoclaving of PVC blood bags is a safer and reliable method compared to chemical disinfection.