As a relatively porous substance, concrete absorbs stains and odors quite easily. Concrete surfaces, common in garages and basements, are often exposed to gas odors and may begin to absorb them. Remove them as soon as you notice them, because the longer the smell is allowed the linger, the more time it will take to remove. Fortunately, common household products are ready to lend a hand.
Fill a spray bottle with white vinegar.
Spray the white vinegar over the entire surface of the floor. White vinegar is an odor neutralizer that metabolizes molecules causing smells.
Let the white vinegar sit for several hours.
Add just enough water to 5 cups of baking soda to make a paste the consistency of frosting. Baking soda is a natural odor absorber.
Spread a thin layer of the baking soda paste over stained, odor-producing areas of the concrete, using the paint scraper or putty knife.
Let it sit for several hours until the layer of paste dries completely on the stains.
Scrape up the paste and discard.
Rinse the area with clear water and let it dry completely.