Respiratory Health in Aseptic Packaging with Hydrogen Peroxide: A Report of Two Cases

Abstract

In the consumer market, there is an increasing demand for various types of fruit juices. To prevent rapid deterioration of the juice the packaging is performed aseptically, commonly employing 5–35% hydrogen peroxide. The workers who operate the packaging machines may encounter inhalation exposure to hydrogen peroxide vapours, and incidental splashes or skin contact with the substance are also possible. Hydrogen peroxide (H 2 O 2 ) is an endogenous metabolite of oxygen and occurs at submicromolar concentrations in aerobic cells. Hydrogen peroxide is able to penetrate biological membranes like water, and the substance oxidises biomolecules unless it is degraded to oxygen and water which readily happens in the presence of catalase or glutathione peroxidase. After oral ingestion or surgical application to body cavities, the rapid breakdown of H 2 O 2 may result in oxygen embolism, sometimes with serious consequences. In local contact, hydrogen peroxide is irritating or corrosive depending on the concentration. Workers engaged in tank loading complained of nose irritation at a measured vapour concentration of 3.5 mg/m . In a controlled study with volunteer subjects, the threshold concentration of the airborne vapour for airway irritancy was 10 mg/m . In the eye, 5% hydrogen peroxide water solution is irritating, and a concentration of 8% or higher caused irreversible damage in the rabbit eye . In rabbit skin, a 10% solution in water was mildly irritating and a 35% solution caused epidermal necrosis probably due to oxygen embolism in the capillaries, whereas 50% or higher concentrations were corrosive. Many workers have noted that inadvertent skin contact to the more concentrated solutions causes white spots which spontaneously disappear within some hours; the change of colour is due to formation of oxygen microbubbles in the skin. Based on a review of historical skin testing results involving hairdressers at two dermatological clinics, hydrogen peroxide is not a skin sensitiser. Long term effects of hydrogen peroxide vapours in the respiratory system have not been adequately elucidated. A limited study performed fifty years ago with dogs suggested that hydrogen peroxide induced lung toxicity at 10 mg/m . In the open literature, there is a case report of a heavily exposed dairy worker who developed interstitial pneumonitis, which the authors attributed to hydrogen peroxide exposure. Presently, the lack of reliable data precludes any possibility of making a health risk assessment for workers who are typically exposed to hydrogen peroxide via inhalation. It would therefore be worthwhile to gather such information from occupational health monitoring programmes and, after critical data analysis, to report them. The present paper deals with the symptoms and respiratory morbidity experienced by a small group of workers exposed to hydrogen peroxide at a fruit juice factory. Althought this investigation is limited by the small number of persons involved, and the restricted method employed, the special circumstances of a change in exposure from high to reasonably low levels, and monitoring of the health status over time, add more weight to the study.