My plumber tells me that he only fits water fittings that are approved because unapproved fittings such as hoses and taps can give taste and odour problems is this true?

Many common plumbing fittings such as taps, flexible hoses, washing/dishwashing machine hoses or even a simple tap washer can give taste and odour problems if they have not been approved by one of the approval bodies. Hoses The main problem is the rubber used in unapproved hoses which can harbour bacterial growth on its surface. Taps Unapproved taps can have rubber washers or O rings in the body of the tap which can give a TCP taste to the water.