bathwater

Bathwater is water that has been used for bathing. It is typically warm and contains residues from soap, shampoo, body oils, sweat, skin cells, and any bath additives such as oils or salts. The exact composition varies with personal hygiene products, water hardness, and the duration of the bath.

In everyday use, bathwater is disposed of through the drain. In some greywater recycling approaches, bathwater can be reused for non-potable purposes such as landscape irrigation, after appropriate treatment or dilution. However, because it contains detergents and personal-care chemicals, direct reuse on edible crops or in sensitive environments is generally discouraged without proper filtration and treatment.

Health and safety: Bathwater should not be ingested. Supervise young children to prevent drowning or accidental ingestion. Leaving bathwater standing for long periods can encourage bacterial growth, so it should be drained after use and the tub cleaned.

Environmental considerations: The wash water enters municipal wastewater systems. Soaps and additives may affect treatment processes and aquatic ecosystems if large volumes are discharged untreated. Using biodegradable, low-toxicity products minimizes impact.

Cultural note: The phrase don't throw the baby out with the bathwater derives from a historical caution about discarding bathwater too carelessly.