There are 2,900 household dryer fires each year in the US according to FEMA. If you want to prevent fire in your home, it's pretty easy.

‍

"Dryer fires are usually caused by lack of airflow, an accelerant, or both."

- Unnamed associate of mine that runs a laundry manufacturer's service department

‍

Airflow

1. Ductwork - The vents on your dryer should be as short as possible with the least amount of elbows possible to maximize airflow. Two 45's are better than one 90. Hard ventilation is better than flexible, but it is a lot harder to deal with. In my home, I have a clean-out right behind the dryer and a 8' flexible vent. I clean the clean-out every few months.
   
   
2. Clean the lint every cycle. Every year, check the machine wherever air is supposed to move and make sure it isn't clogged with lint. If your clothes ever start to take a long time to dry, stop using the machine and investigate what the problem is and call a professional repairman if it is not readily apparent.

Accelerants

If you put rags with flammable liquids in a dryer, it can cause a problem if they are not adequately washed. Hang drying is not ieal, but they won't spontaneously combust on the clothesline. We always wash something twice and dry it on no heat if it is suspect.

Degreasers are particularly useful when dealing with these flammable greases and oils. We use the purple degreaser available at Sam's Club. It is produced by a very well known and competent chemical company I won't name. It's good stuff. You can also use the original blue Dawn, but don't go crazy with it, it can oversuds. Again, good reason to wash twice.

‍

‍
Source

https://www.usfa.fema.gov/downloads/pdf/statistics/v13i7.pdf

My unnamed associate

‍