First of all, try to choose brand products with integrity. Secondly, when you are in the exhibition hall, you should focus on the new samples that seem to have just moved in. You can open places that are not often opened, such as the lower drawer, and then put your face together and blink to see if your eyes are irritating. If so, it means it is not environmentally friendly.
Products that have been in the exhibition hall for a long time generally have no obvious taste, so they are not considered. New samples, you can try a few more. As long as one of them feels that it is not environmentally friendly, the products of this merchant are not optional.
As far as I know, many unscrupulous merchants now use a mixture of qualified and unqualified plates in order to reduce costs.
In addition, buying samples from merchants is sometimes a good choice, not only cheap, but also similar in taste. In addition, it also avoids the inconsistency between the products and samples given by the merchants.