mg/L is milligrams per liter, assuming alcohol has the same density as water (which it doesn't) there are 1000000mg of water per liter. If .08% of it is alcohol that is .0008*1000000mg/L, or 800mg/L, which the poster above listed as 800 parts per million. There are one million "parts" in each liter, so blah blah blah.