from here : http://www.cannabisculture.com/forum...b=5&o=&fpart=1

Unresolved Controversy:
-Vapezilla uses a borosilicate glass around their whip. (See below).
- Wicked Root's marketing strategy seems overbearing and strange (reminiscent of the Vapir, to be honest). Large claims and several mirror sites dominate the web - the company, Wicked Roots, owns several different URLs and stages "reviews" that all claim their product is number one. (This is explained in much more detail below.) They also spam message boards. You can tell who works for Wicked Roots because they have links to their company in every post. Is this a bad thing? Not per se, but it's all unsubstantiated, which makes it controversial.

Price: $300 for analog model, $500 for digital (with display).


Some Terms to Know:

borosilicate glass n. - General term referring to a range of glasses containing silica (typically over 60%) and boric oxide (5-20%). Two specific glasses cover most applications: low expansion Pyrex-type glass; and highly durable 'neutral' glass. Glass fibers, ceramic glazes, and vitreous enamels are also borosilicates.

Boric Acid n. - A flame-retardant compound used to treat wood and other materials. Boric oxide has remarkable and relevant glass-forming, fluxing, and viscosity lowering properties

http://www.chemicalland21.com/arokor...RIC%20ACID.htm

So why do I mention this?

Well, borosilicate glass is on the United States' EPA Toxic Substance Control Act (TSCA) inventory list. It is also considered hazardous under the criteria of the Federal OSHA Hazard Communication Standard 29 CFR 1910.1200.

Here is a link to a study which found that borosilicate glass is stable and generally safe, but poses a toxicity risk when exposed to heat and breakage (glass dust and fibers):

http://www.hummelcroton.com/msds/glsbr_m.html