Efficacy of chlorine sanitizer spray bottles exposed to various temperatures and ambient light

Abstract

Background: Gastroenteritis is largely under reported across Canada. It is estimated that one reported case represents on average 313 cases. In addition, improper cleaning is one of the top ten reported causes of food borne illness. Sanitization is important to reduce the number of pathogenic microorganisms present on food contact surfaces to a safe level. Correct concentrations of sodium hypochlorite are to be prepared and used within the range of 100ppm – 200ppm on food contact surfaces. The purpose of this study was to evaluate the rate of degradation of sodium hypochlorite in spray bottles to assess if these solutions need to be prepared fresh daily to achieve efficacy. Two variables seen within a food service establishment were chosen to evaluate the rate of degradation, temperature and ambient light. Method: Room temperature (20˚C), 35˚C and ambient light exposure were tested to evaluate their effect on the degradation of free chlorine in spray bottles over time in days. The experiment was preformed by setting up 3 individual spray bottles at 20˚C with no light, 20˚C with ambient light and 35˚C with no light. The sodium hypochlorite was then sampled and recorded periodically three times a week over a 15-day period to determine the stability of the chorine solutions prepared at around 200ppm. Results: In the order of spray bottles tested, 20˚C no light, 20˚C ambient light and 35˚C no light, a correlation coefficient of -0.3027, -0.8235 and -0.8169 were recorded. In addition, the following test spray bottles held a r-squared value of 0.0916, 0.6781 and 0.6674. A p-value of 0.5094, 0.0249 and 0.0249 were also assessed, with a corresponding power of 8.99%, 73.74% and 71.75%. Conclusions: By calculating the linear regression formula, it was concluded that chlorine solution in spray bottles do not need to be prepared fresh daily. For 200ppm 20˚C no light, 200ppm 20˚C ambient light and 200ppm 35˚C no light, at days 128, 67 and 45, the estimated concentration of sodium hypochlorite will be at the minimum requirement of 100ppm respectively.