About Protecting Yourself from Legionella in Hot Tubs

Key points

  • People are at risk for respiratory infections if they breathe in mist from a hot tub that contains Legionella bacteria.
  • Legionnaires' disease and Pontiac fever are illnesses caused by Legionella.
  • There are steps you can take to protect yourself from Legionella when using a hot tub.


Properly maintaining hot tubs with the correct disinfectant (like chlorine) and pH levels reduces the risk of germs, like Legionella, from spreading.

When to see your healthcare provider‎

If you used a hot tub in the last two weeks and develop symptoms of Legionnaires' disease or Pontiac fever--such as cough, shortness of breath, fever, or muscle aches--see your healthcare provider right away. Be sure to tell them that you recently used a hot tub.


Legionella bacteria can cause a life-threatening type of pneumonia called Legionnaires' disease. Legionella can also cause Pontiac fever, a milder illness without pneumonia. People can get Legionnaires' disease or Pontiac fever from hot tubs when they breathe in mist that contains Legionella.

People can be exposed to Legionella in hot tubs when these bacteria get into water systems and grow (increase in numbers).

Risk factors

Certain groups of people are more likely to get Legionnaires' disease, including:

  • People 50 years of age or older
  • Current or former smokers
  • People with chronic lung disease, weakened immune systems, or those who take medicines that lower their body's ability to fight germs and sickness.

Prevention steps and strategies

Below are steps you can take to test hot tub water and find out if the hot tub is being properly operated.

  • Buy test strips at your local retailer or pool supply store. Be sure to check the expiration date.
  • Use the test strips to check these levels:
    • Free chlorine level should be 3–10 parts per million
    • Bromine level should be 4–8 parts per million
    • pH should be 7.0–7.8
  • Tell the hot tub operator or owner if you find improper chlorine or bromine levels or pH.

Questions to ask your hot tub operator

  • What was the most recent health inspection score for the hot tub?
  • Are the disinfectant levels and pH checked at least twice per day?
  • Are the disinfectant levels and pH checked more often when the hot tub is being used by a lot of people?
  • Are the following maintenance activities performed?
    • Daily removal of the slime or biofilm layer by scrubbing and cleaning
    • Replacement of the hot tub water filter according to the manufacturer's recommendations
    • Replacement of hot tub water as often as required by the health department or recommended by the manufacturer