Gas Masks

When working outdoors, you can greatly reduce your exposure to the sulfur compounds in vog by using a commercial vinyl or rubber gas mask that’s fitted with cartridges rated for acid gases and particulates: many welding supply shops, and even some hardware stores, stock these items. For optimum performance, make sure that you purchase a mask that is properly fitted to your face and gives a good seal around your nose and mouth. The best way to do this is to find an experienced professional who works at the store to assist you with the fit and can give you tips on how to get the most benefit from the mask. It’s also important to purchase the correct cartridges for these masks: you will need cartridges that remove both dust and acid gases; cartridges that will remove these compounds as well as organic vapors are also readily available. Another important consideration with this type of mask is that their ability to remove gases and aerosols is greatly reduced by the presence of beards and mustaches due to the poor seal between the mask and your skin. (In critical work environments, where properly fitted masks are required, beards and mustaches are prohibited.) These suggestions are only useful if you are located a safe distance from the source of these gases; at very high concentrations of sulfur dioxide and particulates, the ability of the mask to remove these materials can be overwhelmed and you could very easily be overcome by these gases and seriously injured or killed by that exposure.

Types of masks: Above: A home-grown remedy for filtering out SO2 involves soaking a paper dust mask (left) or a bandana (right) in a solution of water and baking soda, then allowing it to dry. These types of masks may provide some reduction in exposure but are not nearly as effective as a mask or respirator (right) that has been professionally fitted and has the proper cartridges for removal of acid gases and aerosols. These respirators cost around $50 at a hardware or construction supply outlet.

Conventional dust masks that are found in most hardware stores are not nearly as effective as the more sophisticated masks intended for acid gas removal. In times past, when mask technology was less sophisticated, and when gas masks were much less common, the inexpensive dust masks were soaked in a baking soda paste and then allowed to dry before use as a gas mask. Although some relief was obtained using this strategy, they are a poor second to a properly-fitted gas mask.

However, per IVHHN, “The Hawaiʻi Department of Health (HDOH) does not recommend the use of respirators by the general public to protect against volcanic gases. Safe occupational use of respirators requires correct mask and/or filter cartridge selection, physician screening, annual fit testing and training on correct use, maintenance and storage.”

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