Carbon monoxide is a colorless and odorless gas that usually goes unnoticed without a detector. Every house should have at least one fire extinguisher, ideally two. The size of your fire extinguisher is dictated by need. GFI boxes should be in every bathroom and kitchen. Electrical appliances and water don't mix and this device will cut off current when properly installed.
Household chemicals are the most overlooked safety hazard.
Read the labels for directions on storage and never mix volatile chemicals. The best examples of this are chlorine products and ammonia products. A gas is produced that can be hazardous to your health. Drain cleaners should also be handled carefully. When pouring into water, never use cleaners that contain acid.