While DEET is considered safe when used as directed, it's important to take some precautions to ensure its proper and safe use. Here are some precautions to keep in mind when using DEET:

1. Read and follow instructions: Carefully read the instructions provided by the manufacturer on the product label. Follow the recommended application methods, concentrations, and reapplication intervals. Different DEET-based products may have varying instructions, so it's important to familiarize yourself with the specific product you are using.

2. Avoid young children's hands: Avoid applying DEET directly to the hands of young children. They may rub their eyes, touch their mouth, or put their hands in their mouths, potentially causing irritation or ingestion of the product. Instead, apply DEET to the child's clothing, avoiding contact with their hands.

3. Avoid contact with eyes and mouth: DEET should not come into direct contact with the eyes or mouth. Take care when applying DEET to the face, and use your hands to apply it in a targeted manner, avoiding contact with the eyes and lips.

4. Avoid open wounds and irritated skin: DEET can cause irritation when applied to broken or irritated skin. Avoid applying DEET to areas with cuts, scratches, rashes, or sunburn. If you have any broken or irritated skin, it's best to wait until the skin has healed before using DEET.

5. Use in well-ventilated areas: When applying DEET, do so in well-ventilated areas to minimize inhalation of the product. If using aerosol sprays, apply them outdoors or in areas with good air circulation.

6. Avoid ingestion: DEET is meant for external use only. Do not swallow or ingest the product. If accidental ingestion occurs, seek medical attention immediately.

7. Store properly: Store DEET-based products out of the reach of children and pets, in a cool, dry place according to the manufacturer's instructions. Avoid extreme heat or direct sunlight, as it can affect the stability and efficacy of the product.

8. Wash hands after use: After applying DEET, wash your hands thoroughly with soap and water to minimize potential transfer to the eyes, mouth, or food.

9. Consider alternatives for sensitive individuals: Some individuals may experience skin irritation or sensitivity to DEET. If you have a history of skin reactions or allergies to DEET, consider using alternative insect repellents containing other active ingredients such as picaridin or oil of lemon eucalyptus.