As volcanic eruptions spew toxic gas into the air, some residents of Hawaii’s Big Island are frantically searching for masks for protection. But the Hawaii Department of Health says “no commercial mask sold in stores” would actually do residents any good. “I’m just worried about, you know, the air quality,” resident Clayton Thomas told CNN affiliate KHNL/KGMB. He wanted to get a mask for his nephew, who has asthma, but went to five different stores with no luck. By Sunday afternoon, 17 volcanic fissures had opened, pouring lava into the area, according to the Hawaii County Civil Defense Emergency System. And one of the biggest health and safety concerns is the sulfur dioxide in the “vog,” or volcanic smog, coming from the vents. At high concentrations, vog can cause headaches and irritation to the lungs and eyes, according to the University of Hawaii at Hilo. It can induce asthma attacks and cause shortness of breath or other respiratory problems. That’s why Myke Metcalf sold out of all his protective masks within 15 minutes of opening his store on Friday, according to KHNL/KGMB. He had lines of people wrapped around his shop, Pahoa Auto Parts, to buy the masks, which he’s selling at cost. “Some people are just so tired of hearing ‘no’ that they just turn around and walk away,” he said. “Some people say, ‘Well just sell me some for my kids, I don’t need one for myself.’” He wants the government to step in and help, the local station reported. But according to the Hawaii Department of Health, the masks – particularly the common N-95 or other dust masks – wouldn’t help protect residents against sulfur dioxide anyway. In a statement earlier this month, the department cautioned consumers, saying “no mask sold in stores provides protection from the extremely dangerous volcanic gases that are being released from the current volcanic eruption.” Even respirators and gas masks aren’t recommended by health officials for use by the general public, in part because proper use of respirators requires correct filters and training to ensure proper fitting and use, according to the International Volcanic Health Hazard Network, Hawaii Department of Health and the US Geological Survey. The masks “don’t work against gases,” Hawaii County Mayor Harry Kim said on Twitter Sunday. “Please let your ‘ohana (family) know that the best thing to do is to avoid the gases by staying indoors with your windows shut, or by vacating the area when you perceive the gas emissions are affecting your breathing,” he wrote. Residents should simply stay away, the Department of Health says. “The best way to protect yourself and your family from the extremely dangerous volcanic gases is to leave the immediate area of the volcano defined by the police and fire department,” it said in a statement.