How long is the expiration date for soap?

pu1. I don't think there's an expiration date for chemical soap

2017-10-30

OK

pu2. If the soap flows into the river, it will decay and the ingredients will disappear, so there will be an expiration date

2017-10-30

OK

pu3. I heard that natural soap sold these days has functional ingredients such as houttuynia cordata, aloe, EM ingredients, flophoris, and grains, so these have a shelf life of 3 years

2017-10-30

OK