What is the best method of washing infested laundry?

As an exterminator specializing in multi family I have noted that suites surrounding the laundry room are more prone to bed bug infestations than other suites. I have also noted a private home with a relatively small infestation and the owners complained they saw bugs coming out of the heating vents on the floor of the bathroom (the laundry area was directly below the bathroom). In the age of chemical resistant bed bugs it is important that we minimize the inadvertent spread of bed bugs via the laundry.

I think the most likely method of infesting laundry areas is in the transfer of infested clothing from the hamper to the washer – the bugs fall onto the floor in the process. As such our local bed bug authorities have encouraged tenants to purchase dissolvable laundry bags with the hope of minimizing that issue. A better and cheaper solution is to lay a sterilized bed sheet on the ground and place a load of laundry in the middle of the cloth. Then pull the corners together and make a ball of laundry. Then take the ball of cloth directly to the washing machine, place entire “bag” at the bottom of the tub, and then balance the load without lifting the clothing.

A second issue arrises out of the temperature of the water in the washing machine. We know that we need a minimum of 122f to kill the eggs and if the water does not reach that temperature the bugs may survive. Many hot water heaters are set at the factory at 140f but the risk of scalding accidents have brought about recommendations to reduce temperatures to 120f. The temperature of the water in the typical home will probably be somewhere between 120 and 140f.

As an experiment I tested my own washing machine with a load of towels. I set the machine to “large” load and filled the machine on “hot”. My own water temperature at the tap was 136.9f. However, after filling the washing machine and letting it agitate for 1 minute I found the water temperature was 128f – a difference of 8.9 degrees. It seems that by the time the water heated the washer, the towels, and the copper pluming leading to the washer the temperature dropped considerably. As such if I wanted to ensure that my washer reached 122f I need a minimum input temperature of 131f which could cause serious burns within 30 seconds. Of course there are many variables in residential settings such as the size of the plumbing pipes, type of washer, distance of the hot water tank from the washer and how much clothing is in the load so every home will require a slightly different minimum hot water setting to ensure the death of bed bugs. And of course the safety concerns might necessitate a temperature lower than 131f.

From a bed bug perspective I suggest sterilizing infested clothing in the dryer for 10 minutes before washing as the dryer on hot operates at 180f which is extremely efficient in killing bed bugs. Then wash the clothes in warm water and redry.

From an integrated pest management perspective I suggest we need to rethink laundry areas as infested clothing is probably going to be washed before the bugs are noticed. And most people, if they assume they do not have bed bugs, are not going to be super careful about ensuring clothing loads are carefully “bagged” which leads to the spreading of bugs to the basement which makes the exterminator’s job more difficult and costly. As such I suggest that laundry areas be located as close as possible to the bedrooms on the same floor. This way if bed bugs are inadvertently spread via laundry the problem is more contained.

In multi family settings it is almost impossible to get away from communal laundry facilities. As such the best policy is to inspect each suite for bed bugs regularly to minimize the risks to others in the building. If infestations are caught early the risk is smaller.

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