How long can lice live on bed linen?

How long can lice live on bed linen? - briefly

Head lice can survive on bedding for about two to five days, depending on temperature and humidity; cooler, dry conditions reduce survival time to roughly 48 hours. They cannot feed without a host, so their lifespan off‑person is limited to this period.

How long can lice live on bed linen? - in detail

Lice are obligate parasites; without a human host they cannot feed and quickly lose viability. On fabric such as sheets, the adult stage survives only a short period, typically 24–48 hours under normal indoor conditions. Factors that shorten this window include low humidity (below 40 %) and temperatures under 68 °F (20 °C). Conversely, warm, humid environments (70–80 °F, 20–30 % relative humidity) can extend survival to about 72 hours, but not beyond three days.

Eggs (nits) are more resilient because they are protected by a hard shell. When detached from a scalp, nits can remain viable for 7–10 days, provided they are kept moist. Dry, heated conditions reduce their lifespan to approximately three days.

Key points for managing contaminated bedding:

  • Wash linens in water ≥ 130 °F (54 °C) for at least 10 minutes.
  • Dry on high heat for a minimum of 20 minutes.
  • Seal unwashed items in a plastic bag for 48 hours to starve lice of a blood source.
  • Vacuum mattresses and surrounding areas to remove stray nits.

In summary, adult lice on sheets are unlikely to survive more than two days, while detached eggs may persist up to a week under favorable conditions. Prompt laundering and heat treatment effectively eliminate the risk of re‑infestation from bedding.