Is PEG 400 dangerous to consume?

By: Chris Edwards
August 9, 2017

Occasionally, we are asked by our patients about the safety of Polyethylene Glycol, aka "PEG 400", which is used to reduce viscosity in our O.penVAPE PEG'd vaporizer cartridges. PEG 400 is "a low-molecular-weight grade of polyethylene glycol. It is a clear, colorless, viscous liquid. Due in part to its low toxicity, PEG 400 is widely used in a variety of pharmaceutical formulations".

Recently, a handful of articles have been published suggesting that PEG 400 may cause unsafe compounds to be inhaled when consuming through vaporization of cannabis or tobacco products. For example, https://www.leafly.com/news/health/cannabis-vape-oil-ingredients-to-avoid.

The purpose of this blog post is to take an objective look at the facts. First of all, the "research" group that conducted the study is called the "Medical Marijuana Research Institute." This organization, based in Arizona, is affiliated with an Arizona dispensary called Harvest of Tempe. Harvest of Tempe produces a competing product called Dream Steam. Clearly, there is an immediate conflict of interest by virtue of who is making this claim.

Secondly, Dream Steam uses Medium Chain Triglycerides ("MCT") oil as their carrier, as opposed to PEG 400. The study, which once again is highly biased, concluded that MCT is the safest carrier. However, MCT has a much LOWER smoke point than PEG 400 (350 degrees Farenheit versus 446 degrees Farenheit). So does the study actually suggest that smoking MCT oil is safer than vaping PEG?

The study was supposedly conducted at a temperature of 446 degrees Fahrenheit, which is considerably hotter than O.penVAPE pens can reach. Assuming for a moment that the data shown by the study was correct, a patient would never combust PEG 400 at a temperature even close to 446 degrees Fahrenheit. For reference, O.penVAPE pens reach a theoretical maximum temp of around 340 degrees Fahrenheit.

If you are interested in doing your homework on this topic, we suggest reviewing the following study performed by the US Pharmacopeia Society, an independent, and credible research group having no bias whatsoever. The results of their study were published in High Times last year, which suggests PEG 400 is actually the safest cutting agent for use in vaporizer cartridges because it breaks down less relative to all other alternatives at realistic operating temperatures:

http://hightimes.com/grow/is-e-liquid-safe/

Last, but not least, PEG 400 is the preferred carrier used by pharmaceutical companies for inhalants. An example being Symbicort. PEG 400 is also an FDA GRAS (generally regarded as safe) substance. We hope this helps to clarify the facts, and we are happy to answer any questions that you may have!