AllergenWash can be used safely in HE washers. HE washers use several sensors to indicate the wash progress. HE detergents must be low sudsing to avoid interference with these sensors. AllergenWash is a low sudsing detergent, but to use it in an HE washer you have to reduce the amount of AllergenWash to slightly more than half the volume of the scoop provided. In other words, for a regular size load in a standard washer you use 3/4 of a scoop, in an HE washer for a regular size load you will use slightly more than half, but less than 3/4 of a full scoop. (to be exact, fill 0.66 or 2/3 of the scoop instead of 3/4. I assume you have the scoop that comes with the AllergenWash bottle). Reducing the amount of AllergenWash used in an HE washer does not interfere with its allergen fighting ability, as the HE washer is more efficient and is better in dispersing and agitating the product in the wash.