Plastic Compounds in Tea Bags: Source of Potential Toxins
The now defunct Dexter Corporation was the initial owner on the patent6 of a method for treating both tea bags and coffee filters with latex (plastic), to aid in preventing tears that allow the tea leaves/coffee grounds to leak. This invention "saturates and completely impregnates" the entire web material. Therein lies one of the problems with paper tea bags as they are frequently treated with epichlorohydrin, which hydrolyzes to the carcinogen 3-MCPD when contact with water occurs.
Dow Chemical Co is one of the largest producers of epichlorohydrin. According to safety literature7 from Dow, it's a very dangerous chemical that requires using extra precautions when handling. Granted, that doesn't automatically render it dangerous in the final product, but it can still be a cause for concern, particularly as it can turn into a carcinogen when water is added. There are many unanswered questions with respect to the potential hazards of using this chemical in products specifically designed to be used with boiling water...
A good way to protect yourself and your family in this area is to purchase your tea from manufacturers who can certify that their tea bags do not contain this compound. Organic India, for example, has sent me a confirmation that the paper used for their tea bags does not contain epichlorohydrin. In a 2009 article, Kristie Leong, MD also claims to have done her own inquiries and that Bigelow Tea Company does not use the chemical in their bags8. Many plastic tea bags are advertised as "silky" or "mesh bags," or they'll have fancy shapes or oversized bags. I'd suggest avoiding those as well if you want to be on the safe side.
Your best option would be to opt for loose tea. This does take longer, but it can be well worth the wait. One of my favorite teas is Royal Matcha Green Tea, which has one of the highest levels of the potent antioxidant epigallocatechin gallate (EGCG). Unlike other teas which you steep and strain, matcha tea is a powder made from ground green tea leaves. You add the powder right into the water. You are consuming the whole leaf, which makes matcha one of the healthiest green teas available. Another excellent option is loose Tulsi tea leaves. This well-known Ayurvedic herb is also full of antioxidants that fight free radicals in your body and prevent oxidation damage.