In general, the inner liner is made of special clay with fine texture and high iron content at 1 100℃, mainly reddish brown and hard texture. Non-toxic, just use it.

Some products containing manganese dioxide and nickel oxide are really toxic. It is carcinogenic.

I have never used this brand before. If it is produced by a regular manufacturer with a certificate of inspection and a large sales volume, there will generally be no problem.