Generally speaking, most people are turning towards non-toxic cookware, and that includes kettles too. Many companies have clocked onto consumers' "healthier" habits and have therefore ditched plastic for silicone, stainless steel, or Borosilicate glass. This is because plastic can leech endocrine-disrupting chemicals such as Bisphenol A (BPA) and phthalates. However, when shopping for a metal kettle, you should look out for 04 or 316 food-grade stainless steel.