In the continued war on e-cigarettes, we hear about the “potential dangers” of e-cigarette vapor and the “unknown public health risks.”
First, I find it absolutely absurd that we’re attempting to pass laws based on unknowns, but what makes it even more absurd is the fact that there’s very little that isn’t known about e-cigarette vapor at this point. The primary ingredient of concern to those who wish to see e-cigarettes banned is the propylene glycol vapor, which has been studied for over 70 years.
I recently came across a document titled, “Reregistration Eligibility Decision For Propylene Glycol and Dipropylene Glycol“, which was created by the United State Environmental Protection Agency (EPA).
Catchy title. I was intrigued.
This quote caught my eye:
Propylene glycol and dipropylene glycol were first registered in 1950 and 1959, respectively, by the FDA for use in hospitals as air disinfectants. (page 4, paragraph 1).
In a previous post, I had shared the summary of research that had been done in 1942 by Dr. Robertson regarding the antibacterial properties of vaporized propylene glycol, but I had never heard that the FDA wound up approving it for the purpose of an air disinfectant in hospitals.
Indoor Non-Food: Propylene glycol is used on the following use sites: air treatment (eating establishments, hospital, commercial, institutional, household, bathroom, transportational facilities); medical premises and equipment, commercial, institutional and industrial premises and equipment; (page 6, paragraph 2)
Method and Rates of Application
Read the directions included with the automatic dispenser for proper installation of unit and refill. Remove cap from aerosol can and place in a sequential aerosol dispenser which automatically releases a metered amount every 15 minutes. One unit should treat 6000 ft of closed air space… For regular, non-metered applications, spray room until a light fog forms. To sanitize the air, spray 6 to 8 seconds in an average size room (10’x10′). (page 6, paragraph 6)
A common argument used to support the public usage ban is that, “Minnesotans have become accustomed to the standard of clean indoor air.” However, according to the EPA and FDA, so long as there’s a “light fog” of propylene glycol vapor in the air, the air is actually more clean than the standard that Minnesotans have become accustomed to.
General Toxicity Observations
Upon reviewing the available toxicity information, the Agency has concluded that there are no endpoints of concern for oral, dermal, or inhalation exposure to propylene glycol and dipropylene glycol. This conclusion is based on the results of toxicity testing of propylene glycol and dipropylene glycol in which dose levels near or above testing limits (as established in the OPPTS 870 series harmonized test guidelines) were employed in experimental animal studies and no significant toxicity observed.
A review of the available data has shown propylene glycol and dipropylene glycol to be negative for carcinogenicity in studies conducted up to the testing limit doses established by the Agency; therefore, no further carcinogenic analysis is required. (page 10, paragraphs 1 & 2)
Ready for the bombshell? I probably should have put this at the top, as it could have made this post a lot shorter, but I figured the information above was important, too…
2. FQPA Safety Factor
The FQPA Safety Factor (as required by the Food Quality Protection Act of 1996) is intended to provide an additional 10-fold safety factor (10X), to protect for special sensitivity in infants and children to specific pesticide residues in food, drinking water, or residential exposures, or to compensate for an incomplete database. The FQPA Safety Factor has been removed (i.e., reduced to 1X) for propylene glycol and dipropylene glycol because there is no pre- or post-natal evidence for increased susceptibility following exposure. Further, the Agency has concluded that there are no endpoints of concern for oral, dermal, or inhalation exposure to propylene glycol and dipropylene glycol based on the low toxicity observed in studies conducted near or above testing limit doses as established in the OPPTS 870 series harmonized test guidelines. Therefore, quantitative risk assessment was not conducted for propylene glycol and dipropylene glycol.
In a paper published in the American Journal of Public Health by Dr. Robertson in April of 1946, Robertson cites a study published in the Edinburgh Medical Journal, which was conducted in 1944:
The report of the 3 years’ study of the clinical application of the disinfection of air by glycol vapors in a children’s convalescent home showed a marked reduction in the number of acute respiratory infections occurring in the wards treated with both propylene and triethylene glycols. Whereas in the control wards, 132 infections occured during the course of three winters, there were only 13 such instances in the glycol wards during the same period. The fact that children were, for the most part, chronically confined to bed presented an unusually favorable condition for the prophylactic action of the glycol vapor.
An investigation of the effect of triethylene glycol vapor on the respiratory disease incidence in military barracks brought out the fact that, while for the first 3 weeks after new personnel entered the glycolized area the disease rate remained the same as in the control barracks, the second 3 week period showed a 65 percent reduction in acute respiratory infections in the glycol treated barracks. Similar effects were observed in respect to airborne hemolytic streptococci and throat carriers of this microorganism.
I don’t expect the prohibitionist lawmakers to delve this deeply into this subject on their own, but I certainly hope that when presented with this data that they reevaluate their stance on the subject and consider what science has to say. If they don’t, they’re simply basing their judgement off of rhetoric, misinformation, and personal bias and we all know where that gets us.