I think the subject's question is inconsistent. Since they are all health teas, why should preservatives be added? It is always harmful to your health. How to maintain health?

Commonly used preservatives are benzoic acid and its sodium salt, sorbic acid and its sodium salt, sulfur dioxide, sodium metabisulfite, potassium metabisulfite, sodium propionate, calcium propionate, ethyl p-hydroxybenzoate and dehydroacetic acid.

There are many kinds of preservatives as food additives, and more than 30 kinds are allowed to be used in a certain amount. For example, sodium benzoate is generally used in soy sauce. Potassium sorbate is often added to drinks, pickles, condiments and preserves. Sulfite is often used in wine, hawthorn wine and other fruit wines.

Whether food containing harmful substances is harmful to human body mainly depends on the amount of food consumed by human body.

Although the two different concepts of food containing harmful substances and food poisoning should not be confused or equated, it can be said that the dose determines the toxicity. In other words, whether preservatives are harmful or not should be determined by dosage, not by type.

But if you make your own health tea, there is really no need to add preservatives.

Especially children, pregnant women and other sensitive people who are in a special period. In principle, it is recommended not to eat foods containing preservatives. Can't you eat anything well?