These medications may also be used to treat thyroid cancer or other thyroid conditions. The long-term safety of levothyroxine is well established. Typically side effects only occur due to overdosage of the medication. For more specific information, consult with your doctor or pharmacist for guidance based on your specific condition and current medications.
My neighbor just puts 3-4 gal of bleach down the pipe, then waits 24 hrs. Then runs water through all the fixtures until the bleach smell is gone. He said it usually last for 1-1/2 years. Our water is relatively soft, but does have a bit of iron in it.
Aerosol air fresheners can last for about 2 years. After that, they begin to break down and lose the lovely fragrance that inspired you to purchase them. Bleach can last between 3 to 6 months. After 6 months it can start breaking down to salt and water. Check the expiration date on the bottle before you use it. Ideally, you want to store bleach somewhere that stays between 50 degrees and 70 degrees Fahrenheit.