# 2010 Vancouver
Water is essential for human life. More than one billion people worldwide do not have access to safe water supply. The World Health Organization (WHO) estimates that more than 4,000 people die each day from diarrheal diseases resulting from unsafe water and lack of sanitation. Ninety percent are children under the age of five who live in developing countries. Disinfection of the drinking water helps to destroy disease-causing microorganisms. Widely used water disinfectants such as chlorine gas; sodium- or calcium-hypochlorite; chlorine dioxide or ozone are strong oxidizers. According to many publications, chlorinated water may have a strong influence on the physical properties and the lifetime of plastic pipes. In most of these papers, aqueous hypochlorite solutions are used, but less information is available on chlorine dioxide. In a comparative lab study, the influence of chlorinated water using aqueous hypochlorite and chlorine dioxide solutions for chlorination in different polyolefin pipe grades was investigated. Obtaining a better understanding of the ageing mechanism enabled the development of polyolefin pipe materials with improved chlorine resistance.