How many days do lice live on items?

How many days do lice live on items? - briefly

Lice can survive on personal belongings for about one to two days, extending to a maximum of roughly five days only under warm, humid conditions before they die.

How many days do lice live on items? - in detail

Lice can remain viable on non‑living surfaces for a limited period. Survival depends on species, temperature, humidity, and the material involved.

• Head lice (Pediculus humanus capitis):

  • At 68–86 °F (20–30 °C) with relative humidity above 50 %, adults survive up to 48 hours. Eggs (nits) lose viability within 24 hours under the same conditions.
  • In cooler, drier environments (below 50 °F or humidity under 30 %), adult lifespan drops to 6–12 hours; eggs deteriorate within 12 hours.

• Body lice (Pediculus humanus corporis):

  • Require clothing or linens to feed. On fabric kept at room temperature and moderate humidity, adults live 24–48 hours. Eggs hatch within 6–9 days, but detached eggs lose viability after about 48 hours.

• Pubic lice (Pthirus pubis):

  • On smooth surfaces such as towels, adults survive 24–48 hours at room temperature; lower humidity shortens survival to 12 hours. Eggs are less tolerant, dying within 24 hours when removed from a host.

Material influences duration. Synthetic fibers (polyester, nylon) retain moisture longer, extending survival by roughly 20 % compared to cotton. Hard surfaces (plastic, metal) dry quickly, reducing viable time to under 6 hours for all species.

Environmental extremes are lethal. Temperatures above 115 °F (46 °C) for 5 minutes or below 0 °F (‑18 °C) for 30 minutes eradicate both adults and eggs. Direct sunlight accelerates desiccation, eliminating lice within a few hours.

Practical implications: washing items in hot water (≥130 °F / 54 °C) for at least 10 minutes, followed by high‑heat drying (≥130 °F) guarantees elimination. Alternatively, sealing objects in airtight plastic bags for 2 days deprives lice of oxygen and humidity, causing death.

In summary, lice survive on objects from several hours up to two days, with eggs persisting slightly longer under optimal conditions. Temperature, humidity, and material type are the primary determinants of longevity.