Factors affecting chlorinated product formation from sodium hypochlorite bleach and limonene reactions in the gas phase

The application of sodium hypochlorite bleach to surfaces causes the release of chlorine (Cl2) and hypochlorous acid (HOCl) into the gas phase where reactions with organic compounds can occur. The purpose of the current study was to investigate the reaction products generated from gas-phase bleach oxidants and limonene, a fragrance compound commonly found in indoor air due to personal care products and cleaning products. Gas-phase reactions were prepared in Teflon chambers housing HOCl, Cl2, and limonene. The resulting chemical products were collected and analyzed using gas-phase preconcentration following by gas chromatography and high-resolution mass spectrometry. Several chlorinated products were detected including a limonene chlorohydrin and limonene species containing one, two, and three chlorines. Product concentration and yields were estimated for the most abundant products, and greater than 80% of the transformed limonene was represented in the detected products. Temporal sampling of the reactions allowed time courses to be plotted for limonene transformation and chlorinated limonene product generation under different conditions including the treatments of HOCl/Cl2, Cl2 only, high vs. low relative humidity, and +/- ozone. These experiments provide additional insight into the chemical transformations initiated by sodium hypochlorite bleach oxidants in the gas phase which may be of interest to human health.