Ventilation was a constant problem in the deep mines of the Crowsnest Pass. Miners and ponies needed fresh air to breath and fresh air was also critical for safety. Many mines produced dangerous gasesmethane and coal gas. Very fine coal dust could be highly explosive and a spark could result in a fatal explosion. When methane mixed with oxygen (CH4) it was called "fire damp" and was very dangerous. Other gases, including carbon monoxide, called "whitedamp" by miners, or "black damp" which was a mixture of air and carbon dioxide could accumulate in mines and be poisonous to the miners.
A tremendous amount of methane was produced in the Crowsnest mines. A study from the 1920s estimated that 3,640 cubic feet (103 m3) of methane gas was given off for every ton of coal produced. Moreover, in some areas "blow-outs" of methane occurred. These could measure over 100,000 cubic feet (2 832 m3) of gas accompanied by fine coal dust which itself could represent as much as 100 tons or more fine coal dust. In some mines, the outburst could become so severe and dangerous that the mines had to be closed. For example, in August 1903, an outburst occurred at Morrissey which blew out 1,630 tons of coal and a large volume of methane. In October, another outburst blew out 800 tons of coal accompanied by methane and four miners were suffocated. Then in November 1904, a further outburst discharged 3,500 tons of coal, millions of cubic feet of methane and killed 14 men. After that, the mine was closed. Some outbursts were even more extreme and the blasts could be felt on the surface. One at Coal Creek in 1927 was estimated to have released 3.5 million cubic feet (99 110 m3) of methane.
The mines required very effective ventilation systems to keep the levels of explosive gases to a minimum or safe level and to make sure there was fresh air for the miners to breath. In the Crowsnest mines, ventilation fans, depending on the size of the mine, could deliver from 30,000-180,000 cubic feet (2 800-16 700 m3) per minute to the workings.
Most mines had large ventilation fans built at the surface which were used to draw air out of the mines. Special shafts were dug to permit fresh air to enter the workings. Booster fans were used to force air further into the workings. If for some reason the ventilation in a mine was inadequate, the consequences could be disastrous and gas explosions killed hundreds of miners in the Crowsnest coal field over the years. Gas tests were carried out routinely within the mines.
Breathing fine coal dust over many years could lead to a disease known as pneumoconiosis of coal miners or "black lung." The disease progressed from causing coughing and minor lung impairment to progressive loss of lung capacity, increasing disability and possibly death.
"Bumps" were a dangerous feature of the Crowsnest mines in the Fernie-Morrissey-Michel areas. In mines deep underground, the overlying rock places enormous pressure on the mine workings. Once coal was removed, the pressure of the rock and water in the rocks above could be released with sudden force producing a impact similar to a local earthquake that could severely damage the workings and was very hazardous to the miners. Generally, it was believed that workings with over 2,500 feet (760 m) of overlying strata were most likely to suffer from bumps.