There are some good third party testing resources out there- check out Clean Label Project and Lab Door
Both of these sites are great places to check out heavy metal levels of various supplements, protein, etc.
Research studies showed that VEGAN protein powders were much higher in heavy metals that non vegan. It was shocking. I’ve seen the study years ago and was just looking for it again. The Environmental Working Group, a women scientist founded organization, has a great web site to find out toxic levels of all kinds of products we use. Someone told me today that their web site is not as user friendly as it once was. I thought this was the organization that published the info but cannot seem to find it. I used to teach nutrition. Most Americans eat more protein than needed. Too much protein is hard on the kidneys which have to process all the ammonia.
Im sorry I gotta be the guy that says, none of them are safe. They aren’t regulated. Any numbers you’re receiving could have been taken at any time from any batch. Not only have countless supplements been proven to contain harmful substances, they are also inconsistent in composition. So you could be getting far more or less in each batch you purchase.
Aside from all that, if you aren’t concerned about your health, they are expensive and essentially useless. What’s wrong with just eating food? How much protein do you really need?