Is taking laundry powder across national borders by plane likely to cause any problems?
I'm not worried so much about airport security, as border protection forces mistaking it for heroin.
I'm travelling to Hong Kong, Mongolia, South Korea, Japan, and China, but not to the USA.
No, it is not.
They will take a sample and run it through an opioid test; which looks like this (image from Sirchie):
Next, they will probably wonder why on Earth would someone carry laundry powder in their luggage.
The people you need to worry about are customs enforcement, and not border protection (although sometimes, these are the same agencies).
