The state stipulates that the content of formaldehyde in every 100 grams of floor samples does not exceed 0.5 mg, which is the requirement of Class A (Eo grade, equivalent to the environmental protection standard of similar products in Europe), and the content of formaldehyde in every 100 grams of floor samples does not exceed 40 mg, which is the requirement of Class B. So it's not completely absent, it's just a small amount, but it's also reflected in the superposition effect!