On May 19, the Frontal 21 news program produced by Germany’s ZDF television network broadcast a program on Gasodor® S-Free odorant. By omitting certain information, the producers were able to create the impression that the odorant is not safe as a warning for natural gas. Specifically, the program named two reasons for questioning the suitability of Gasodor® S-Free as an odorant: the substance reportedly smells like an everyday odor and can trigger allergic reactions. Although a several different experts were interviewed over the course of researching the program, Frontal 21 did not broadcast all of their responses.
Frontal 21 visited the Engler-Bunte Institute at the Universität Karlsruhe, for instance, to ask the experts at the German Technical and Scientific Association for Gas and Water (Deutscher Verein des Gas und Wasserfachs e.V., or DVGW) about the accusations. The DVGW approved Gasodor® S-Free for the market in 2001 as the first sulfur-free odorant. The program, however, did not include responses from experts (Engineering professor Dr. Rainer Reimert, and industrial engineer Dr. Frank Graf), nor was there any mention of the fact that the institute operates an office for certifying odorants. Substances are only approved after they have been reviewed according to strict guidelines and scientific methods to ensure suitability. Plus, the DVGW is an independent institute and does not derive any financial gain from the use of Gasodor® S-Free odorant.
Because the responses of DVGW experts were utterly absent from the program, their statements can be read below to allow readers to form their own opinions.
The following are the DVGW’s responses to the questions posed on Frontal 21:
Frontal 21: “Critics maintain that this odorant is not suitable, because it is a common smell that in no way indicates cause for alarm.”
DVGW: “Numerous studies were performed in accordance with valid standards (DIN EN 13725, VDI 3882-1) to determine the characteristics, threshold and intensity of the odorant. The results showed that Gasodor® S-Free is perceived as an unmistakable warning. This was confirmed by collecting reports of gas received in areas where the new odorant had been introduced into the gas supply and subjecting these reports to statistical analysis. Of particular note is the fact that, during the development phase, studies were performed in which Gasodor® S-Free was compared with everyday smells – and the difference could always be detected. The only known case in which switching to Gasodor® S-Free made it more difficult to detect the presence of gas involved a dental laboratory, where staff used a variety of organic solvents, one of which was acrylic-based. It would be difficult to describe that as an ‘everyday odor,’ however. Compare this to the risk of confusing odors posed by THT, a sulfur-containing odorant dating back to the days when coal gas was still used; the smell is reminiscent of the odor of foods containing garlic. The Cologne-Bonn airport recently had to be closed, in fact, because of a ‘gas alarm’ that, in this case, was triggered by a piece of meat in a garlic-based marinade.”
Frontal 21: “Critics claim that Gasodor® S-Free” is allergenic.”
DVGW: “Gasodor® S-Free consists largely of acrylates, which are used in countless processes in the chemical industry. The manufacturer (the Symrise company) commissioned a study on the allergenic properties of the product. The study yielded no evidence that inhaling this material poses the risk of an allergic reaction. In this respect, it is also important to remember that the concentration of the material is very low, even when sufficient is present to serve as a warning of gas. A simple calculation illustrates this point: old gas stoves may be assumed to allow a maximum of 0.5 L of natural gas to escape during the lighting process. This gas then mixes into the surrounding air very quickly. Given that the concentration of odorant in natural gas is 7 ppm (parts per million), this means that the consumer is exposed to an average odorant concentration of 0.0035 ppm. By way of comparison, the TGRS 900 (Technical Regulations for Hazardous Substances) sets the workplace exposure level for the acrylates in question at 5 ppm in the air. The consumer never comes in direct contact with the pure odorant.”
Background: Environmentally safe odorant for natural gas
Contact information:
If you have any additional questions regarding Gasodor® S-Free, we would be happy to receive an e-mail from you and will respond as quickly as we can.
Simply write to the following address: Joerg.Mueller@symrise.com
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