On 20th March 2019, Ma Man Kei and Lo Pak Sam College invited Prof. Xuanjun Zhang, Assistant Professor from the Faculty of Health Sciences at the University of Macau to give a lunch seminar entitled “Daily Life Chemistry and Health”. Prof. Zhang began his talk by introducing the applications and disadvantage of formaldehyde. He pointed out that formaldehyde is regularly used in various types of building materials, preservatives and food industry. He then moved on to talk about the decoration methods in chinaware, he said the dyes used to decorate potteries contain poisonous ingredients such as lead. He explained that there are two methods of decorating potteries, underglaze and overglaze. In underglaze, the dye is painted to the surface on the pottery and covered with a transparent ceramic glaze and fired in the kilin. In contrast, overglaze decoration is where the decoration is applied on top of the already fired and glazed surface pottery.