During the fermentation process, wine grape sugar is metabolized by yeast which converts the sugar to water, alcohol and carbon dioxide. During the active fermentation process, concentrations of carbon dioxide within the headspace of a fermenting tank may reach levels approaching 100% by volume. The danger with this type of build-up includes the displacement of oxygen and the potential asphyxiation of workers as well as the dangers of being exposed to high concentrations of carbon dioxide for an extended period of time. Currently, the OSHA TWA for carbon dioxide is 5000 ppm (.5% by Vol). In addition, during the active fermentation process, closed buildings require monitoring of the atmosphere for carbon dioxide and oxygen levels before entering as concentrations may exceed safe levels. 

In addition to carbon dioxide, sulfur dioxide is also present at wineries. Sulfur dioxide is primarily used as an anti-oxidant of fresh grapes, grape juice and wine at low levels to inhibit yeast and mold growth. Sulfur dioxide is also used to sterilize the empty wine barrels to prevent the growth of yeast and mold. Generally, when working with sulfur dioxide, workers wear protective clothing and respirators, however, in the event that leaks occur from the sulfur dioxide dispensing equipment, monitoring instruments can quickly warn workers before sulfur dioxide levels become dangerous. 

When cleaning wine tanks of settled residue, it is not uncommon to encounter levels of ethyl alcohol approaching the OSHA TWA of 1000 ppm. Portable gas detection instruments can easily monitor levels of ethyl alcohol within this range ensuring compliance and worker safety. 

Confined spaces in wineries such as pits, sumps and tanks containing wastewater may harbor not only combustible gas and oxygen deficiency but may also contain dangerous levels of hydrogen sulfide as well. High levels of hydrogen sulfide not only desensitize the workers sense of smell but, in high concentrations, contribute to respiratory damage and can be potentially fatal. According to the American Conference of Governmental Industrial Hygienists, the 8 hour TWA for hydrogen sulfide is 10 ppm. Levels of greater than 100 ppm are considered immediately dangerous to life and health. 

Carbon monoxide may also pose a concern in wineries. If gasoline powered generating equipment, vehicles or propane forklifts are used in warehouses, exhaust containing high levels of carbon monoxide can build up creating potential hazards for employees. 

Now that you know of the potential atmospheric hazards that may be present at wineries, what can you do to prevent workers from exposure to these hazards? In addition to establishing a solid confined space and atmospheric safety policies, one of the best instruments for use in this application is the Thermo Scientific GT-CO2. This instrument can be easily configured to meet each wineries specific needs. The basic GT-CO2 is configured to detect oxygen content and combustibles in the range of 0-100% LEL as well as 0-10,000 ppm. If required, the ppm combustible range can be set to 0-5000 which gives a higher resolution of detection when using the instrument for ethyl alcohol detection. The carbon dioxide range is available in either 0-5% or 0-20% by volume depending on the level of concern. In addition, this instrument can be supplied with either carbon monoxide, hydrogen sulfide or sulfur dioxide sensors.