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This morning it was -13°F here in central NY. For those of you who aren’t familiar with inhumane, cold temperatures…-13°F is really cold. I hope you never have to experience it.
So I thought today was as good a day as any to talk about heat.
In February 2010, two British scientists from the University of Sheffield, R. A. Naylor and C. J. Boase, published their studies on "Practical Solutions for Treating Laundry Infested with Cimex lectularius (Hemiperta: Cimicidae)" (aka Bed Bugs) in the Journal of Economic Entomology. For a more detailed summary of their findings, see fellow entomologist Mike Merchant’s blog: http://insectsinthecity.blogspot.com/2010/03/guidelines-for-killing-bed-bugs-in.html
Naylor and Boase used freezing, dry cleaning, washing, and drying to kill all life stages of the bed bugs. I’m only going to report to you what worked 100% on all life stages (the eggs are hardest to kill).
|
Weight of dry laundry |
Appliance |
Target temperature |
Time needed |
|
5.5 lbs |
Freezer |
1.4°F* |
10 hours* |
|
--- |
Dry cleaners |
--- |
--- |
|
7 lbs |
Washer |
140°F |
30 minutes |
|
7 lbs |
Clothes dryer |
120°F |
30 minutes |
*Update (10/2012): Research out of UMN found that it takes 3 days at 0°F to kill a bed bug!
Keep in mind that appliances and building-wide water temperature settings will vary. Be mindful of whether your freezers, washers, and dryers are capable of reaching the target temperatures. How can you know? Hot water temperature should be set for the building. The temperatures of dryers and freezers can be determined fairly accurately using an infrared thermometer. Purchasing one of these instruments may be overkill if you’re going to use it for this application alone, but there are all sorts of great uses for infrared thermometers (both fun and practical). Look into it and see for yourself.
Below you’ll find this month’s newsletter article for you to share with residents. I only included dryer recommendations based on this study because this seems to be the most practical recommendation for low-income housing in the US. And I didn’t want the article to be too long.
On a related note: one product you may have heard about is the dissolvable laundry bag. I do know of some housing authorities that are supplying dissolvable laundry bags to residents who are working to get rid of bed bugs. They are an option that you may want to make available to reduce the likelihood that residents will re-infest their belongings and homes by using the same container to transport fabric from and back to their homes.
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Did you know: you can kill bed bugs and their eggs with a clothes dryer?
You will need: 2 trash bags for each load of laundry.
- Put about 7 pounds of laundry in a trash bag. Any fabric that can take high heat can be put in the dryer. Consider bags, pillows, and curtains as well as clothes and bedding.
- Empty the bag of laundry into a dryer.
- Tie off the empty trash bag and throw it away.
- Run the dryer for 30 minutes on the hottest setting.
- Take laundry out of the dryer and put it into the other, unused, trash bag.
- Bring home the bed bug free laundry in the bed bug free bag.
Bed bugs like to hide in more than just fabric. If you find a bed bug, call [ENTER PHA WORK ORDER #]. [PHA] will pay for pest control services if you report the problem and cooperate with control efforts. For more pest control information, check out StopPests on Facebook or Twitter.
good information...
there is always a concern about whether the heat in the dryer is reaching the kill point.
if the system is controlled by thermostat, and there is a licenced heat and air conditioning tech to confirm it is reaching that kill temp, then that's great, but i have found some systems just don't deliver the temperature. One could check by using an infrared thermometer to do spot checks by stopping the cycle for a few seconds, opening the door and taking a surface reading on the clothing towards the end of the cycle when it has lost most of the moisture. Surface readings when the clothing is not at end of cycle can be deceiving as the surface is hot but the mass of clothing may not be at the kill temp at the end of the cycle. Taking the reading at the end of the cycle gives a more accurate confirmation. Another way to measure the temp is using a datalogger temperature sensor that takes readings on a set frequency and the data can be downloaded into a computer by a usb cable.
The loggers have to be well protected (I put the ones i used into a thick sock and leave them in the dryer for the full cycle). It absolutely confirms the kill temp.
the infrared thermometers are pretty good and not expensive, and easy to use. We learned some of the nuances by using both during a trial run and that is how we know that the infrareds are not accurate early in the cycle as the core temp of the laundry load is not at kill when the infrareds show kill on surface early on.
Most dryers reach the kill temp without an issue, and the commercial laundry driers are pretty good, but if there was a deficient system, and heavy infestation, it won't kill the eggs.
Posted by: Sam Bryks | 01/24/2011 at 09:27 PM
The target temperatures for the washer and dryer correspond to what I've heard from other reputable sources, but I've heard various things about the amount of time they need to be sustained at that temperature.
This is what I've been wondering for awhile though: if someone were to wash and dry their clothes to get rid of the bedbugs...where do the bed bugs go? should we also be instructing people to clean out the washer and dryer after use - to prevent the dead bed bugs from getting on the next person's laundry???
Posted by: Steph Reitmeier | 01/25/2011 at 02:43 PM
Hi Steph,
With washing, the bed bugs should just go out with the water. In a dryer, the dead bugs may get caught in the lint screen.
I think the risk of dead bed bugs getting on the next person's laundry is low. Plus, one shouldn't treat for bed bugs until a live bed bug or viable egg is found. Finding a dead bed bug in clean laundry would not warrant further control, just continued vigilant inspection.
Thanks for your creative thinking!
Posted by: Allie Taisey | 01/28/2011 at 02:55 PM
Can I kill the eggs of bedbugs if I just use the dryer and not the washing machine?
Posted by: Elizabeth | 04/02/2011 at 01:01 AM
Elizabeth-
Absolutely. 30 minutes on high heat will kill bed bugs and their eggs if the clothes are dry going into the machine.
Posted by: Allie | 04/06/2011 at 10:33 AM
I really like your post. I found it incredibly usefull. I have to visit your website again some day.Thanks for posting your insights and experiences.
Posted by: Bed Bugs Exterminator Gramercy Nyc | 07/14/2011 at 04:36 AM
This is a problem that effects a lot of people from all walks of life, bugs, all bugs can invade someones home and more or less take over without intervention.
Posted by: Bee Exterminator GreenwichVillage Nyc | 07/22/2011 at 03:28 AM
Some really helpful info here. I was looking exactly for the temperature to kill these bugs. I already use a clothes dryer and it seems to work good for me. Thanks again.
Posted by: Best Washer And Dryer Reviews | 01/22/2012 at 02:11 PM