Charcoal Ash

• Charcoal consists of numerous materials that are unsafe for lawns or plants. Briquettes consist of materials such as sawdust, starch, limestone, sodium nitrate, brown coal and charcoal. Anyone of these materials spread across or dumped on the lawn harms plants. Oftentimes, gardeners use natural briquettes that contain starch and charcoal. However, the organic material leftover from using natural briquettes harms lawns by adding too much potassium to the soil.
  
  

Potassium

• When charcoal briquettes are heated, carbon material is burned off, according to the Harnett County website. This carbon material contains a high percentage of potassium. Potassium is a salt that is found in fertilizers. Plants use potassium for growth, however, too much potassium burns plants, much like too much nitrogen causes dehydration. Gardeners who spread charcoal ashes over the lawn run the risk of burning their plants or causing nutritional problems. An excessive amount of potassium in the soil prevents plants from absorbing other important nutrients needed for growth.
  
  

Lighter Fluid

• Oftentimes, lighter fluid is added to charcoal briquettes either in production or by the cook. Lighter fluid is a petroleum product that is harmful to plants and people. One way to know if your briquettes contain lighter fluid is to smell the grill while food is cooking. An unpleasant gas smell indicates that the charcoal contains lighter fluid. Also, food that tastes like lighter fluid was cooked over this harmful fire-starting product.
  
  

Charcoal Ash Removal

• Avoid placing charcoal ash in your compost. Composting charcoal ash will not remove harmful materials or reduce its percentage of potassium. Allow the charcoal to cool down for 48 hours before throwing away. Scoop up charcoal ash and pour into a garbage bag. To prevent a major mess, wait for a wind-free time of day to dispose of your charcoal ash. Tightly secure the bag and place with the rest of your garbage.