If you detect a sulfur or rotten egg smell in your home, it could be the odorant that Xcel puts in natural gas to help detect leaks. If you notice the smell, leave your home immediately! Do not turn any electrical devices on or off and do not use a garage door opener. Avoid anything that can create a spark. Once you are outside and safely away, call us at 1-800-895-2999 or call 911.