How long are bedbugs treated with cold fog? - briefly
Cold fog treatment for bedbugs is usually applied for 24–48 hours, then a second cycle is scheduled about one week later to target any newly hatched insects. The process may be repeated after 7–10 days if monitoring indicates continued activity.
How long are bedbugs treated with cold fog? - in detail
Cold‑fog treatment, also known as cryogenic fogging, relies on rapid temperature reduction to kill bed bugs at all life stages. The method uses liquid nitrogen or carbon dioxide to produce a dense, sub‑zero fog that penetrates cracks, voids, and fabric.
A typical fogging session lasts 5–15 minutes of active discharge. After the fog is released, the ambient temperature in the treated space is allowed to drop below –20 °C and remain at that level for 30–45 minutes. This cooling period ensures that eggs, nymphs, and adults are exposed long enough to cause lethal thermal shock.
Most protocols require two to three fogging cycles. The cycles are spaced 24–48 hours apart to address any survivors that may have hatched after the first exposure. Each cycle follows the same active‑fog and cooling sequence.
Factors that modify the overall duration include:
- Size and layout of the area (larger rooms need longer fog generation and cooling time)
- Insulation quality (well‑insulated spaces retain cold longer, reducing required cooling time)
- Initial infestation level (heavier infestations may need additional cycles)
- Ambient temperature before treatment (colder starting temperatures shorten the cooling phase)
Professional guidelines, such as those issued by the EPA and WHO, specify that the target temperature must be maintained for a minimum of 30 minutes after fog dispersal. Temperature loggers should be placed at multiple points to verify compliance. Equipment manufacturers often recommend a fog output calibrated to achieve the required temperature drop within the specified time frame.
Safety measures include:
- Removing heat‑generating devices and open flames
- Sealing doors, windows, and ventilation ducts to prevent fog escape
- Wearing insulated gloves, eye protection, and respiratory protection
- Ventilating the area after the cooling period before re‑occupancy
In practice, a complete cold‑fog eradication program spans 2–4 days. Each day involves a single fogging event of 5–15 minutes, followed by a 30–45 minute cooling interval. The total exposure time for bed bugs across all cycles typically ranges from 60 to 135 minutes of sub‑zero conditions. This schedule balances efficacy with operational safety and minimizes the risk of re‑infestation.