Untreated harvested rainwater should not be distributed to which of the following fixture outlets?

Untreated harvested rainwater should not be distributed to kitchen sinks primarily due to health and safety concerns. Kitchen sinks are commonly used for food preparation and dishwashing, which involve direct contact with items that will be ingested. Rainwater can contain contaminants such as bacteria, pathogens, and pollutants that may have accumulated during the collection process, making it unsafe for these applications.

While bathroom sinks, showers, and washing machines may also have some risks, they are typically not involved in the direct serving of food or preparation of meals in the same way that kitchen sinks are. Therefore, kitchen sinks are subject to stricter health regulations regarding water quality, necessitating the use of treated or potable water to ensure safety for culinary purposes. Using untreated rainwater in such settings poses a higher risk of exposure to harmful microorganisms and contaminants, hence it is advised against.