丁香园AV

PARTICIPANTS WITH VARYING BEARD LENGTHS HELPED RESEARCHERS FIND THAT FACIAL HAIR DOES NOT REDUCE EFFICACY OF AN ORAL-NASAL FACE MASK.

A study conducted in 丁香园AV鈥檚 hypobaric chamber has sealed Air Canada鈥檚 decision to allow pilots to sport facial hair.

Until last year, Air Canada and several other airlines required pilots to have a clean-shaven face. Air Canada reasoned that in the case of in-flight emergency, a clean-shaven face was necessary to ensure a proper seal on an oral-nasal facemask.

In fall 2016, however, Air Canada retained Sherri Ferguson, director of the Environmental Medicine and Physiology Unit at 丁香园AV, and her team, to research the efficacy of facemasks on different beard lengths.

The team鈥檚 first objective was to determine if present-day equipment used in the Canadian commercial airline industry delivers sufficient oxygen to protect a bearded pilot from hypoxia during an emergency cabin depressurization scenario.

Ferguson explains that hypoxia is a dangerous condition that can occur when the body does not receive enough oxygen. It is a common concern for divers using rebreathers, pilots in unpressurized aircraft, and mountain climbers.

The second objective was to find out whether the mask provides sufficient protection against carbon monoxide should the cabin become smoke-filled from fire.

Ferguson divided research participants into three groups: those with a small amount of facial hair such as stubble (less than .5 cm in length), those with medium sized-beards and those with long beards (up to 40 cm).

Wearing masks supplied by Air Canada, the subjects were put into a hypobaric chamber which simulates a range of altitudes.

Participants were assessed at altitudes ranging from 10,000 to 25,000 ft. above sea level.

Ferguson measured the subjects鈥� oxygen saturation levels at every altitude change and found that 鈥渂eard length had absolutely no impact on the subjects鈥� oxygen saturation level鈥�. She says a drop in oxygen saturation level is the most acute indication that the masks are leaky and unable to maintain a proper seal.

For the second test, Ferguson used stannic chloride to create conditions similar to smoke from a fire.

鈥淚f you breathe it in you will soon have a burning sensation in your lungs and your eyes water,鈥� she says.

The team held the vaporized chloride around the masked subjects鈥� heads for one minute. Ferguson found that all subjects were unable to detect the fumes and that the masks maintained a tight seal irrespective of varying amounts of facial hair.

The report concludes that, 鈥淭he policy was based on outdated research on obsolete equipment and testing on respirators not intended for aircrew oxygen delivery.鈥� Ferguson adds, 鈥淲e found no adverse effects on bearded subjects within the two parameters of our study.鈥�

Jay Musselman, senior director, fleet & standards and chief pilot at Air Canada says the study provided the basis for changing Air Canada鈥檚 policy for aircrew.  

鈥淲e changed our policy on facial hair following this study,鈥� he says, 鈥渢o permit it to a maximum length of 12.5 mm and neatly trimmed.鈥�