Rosacea Dry Eyes and Rosacea Dry Skin

Airplane Cabin Relative Humidity and Your Home Relative Humidity

A rosacea flare up can happen anywhere or at anytime. Some places that we might not think would cause a rosacea flare up. Our house or even a long airline flight. For the airplane It’s caused by a low relative humidity level in the cabin, and you can solve it by hydrating yourself before flying. We have often heard of this, but forget to do it.

A relative humidity above 60% can cause serious allergy problem with molds growing. While a low relative humidity can cause discomfort for humans with resulting dry nasal membranes and overall dry skin.

Mold and bacteria grow better in more humid environments, however, a dry environment can be detrimental to humans as the mucus linings of the respiratory system, which are a first line of defense against disease. People start to have medical problems when relative humidity gets below 25 percent or above 60 percent for a prolonged time.The ideal humidity for a home or office would be between 45% to 60% humidity.1

Pressurized aircraft cabins are notorious for their low humidity. So humidity in an aircraft is more easily recognized than in our home or office or outside working. In 1999, Boeing admitted that aircraft “typically operate in the 10-15 percent relative humidity range.”2 Cabin air is pressurized, and fresh air comes from bleed air extracted from the engines in older planes (or compressors in newer planes).3 The relative humidity of outside air decreases drastically at higher altitudes. Unfortunately, studies have shown that attempting to increase the humidity of cabin air by reducing the flow of dry air from outside the plane leads to a different set of health complications due to the increase of contaminants.

To compensate for the dry conditions onboard a commercial airplane, we recommend hydrating yourself by drinking water before boarding the plane. This will help prevent the dry eyes and discomfort caused as your body’s water is sucked away by the dry air. And obviously, the same rules apply to our dry homes, or office building or outside work or recreation.


  • Relative Humidity by Joseph Lstiburek, Ph.D., P.Eng.
  • Airliner Cabin Air from (Boeing’s current cabin air statement)
  • Pressurized cabin from Wikipedia