| Reduce indoor aerosol exposure | Do not use the device in enclosed shared spaces. Use it outdoors and away from children, pets, doors, windows, and air-intake vents. | Every use | E-cigarettes produce an aerosol rather than harmless water vapor. Outdoor use reduces indoor accumulation but does not eliminate exposure. | High |
| Prevent leaking e-liquid | Keep the device upright in a cool, dry place. Wipe visible liquid with disposable material and wash hands afterward. | After filling, transport, or any leak | Many e-liquids contain nicotine, which can be harmful if swallowed or absorbed through skin. Keep liquid away from children and animals. | High |
| Inspect the battery and casing | Stop using the device if the battery is swollen, dented, cracked, unusually hot, leaking, hissing, or producing a burning smell. | Before each use and after dropping or water exposure | Damaged lithium-ion batteries can overheat, ignite, or enter thermal runaway. Do not attempt to repair a damaged battery. | Critical |
| Charge safely | Use the charger and cable specified for the device, place it on a nonflammable surface, and keep it away from bedding and heat. | Every charging session | Do not charge unattended, overnight, or near combustible materials. Disconnect when fully charged unless the device instructions state otherwise. | High |
| Clean the mouthpiece | Turn the device off, remove the pod or cartridge if possible, and wipe the mouthpiece with a clean, dry disposable cloth. | When residue, condensation, or dirt is visible | Avoid immersing the battery or electronic parts in water. Do not share mouthpieces because saliva can transfer germs. | Moderate |
| Replace worn components | Replace a pod, cartridge, coil, or seal when it is cracked, burnt, blocked, leaking, or no longer fits securely. | At the first sign of damage or malfunction | Continuing to use damaged parts can increase leakage, overheating, and unwanted aerosol or burnt-material emissions. | Moderate |
| Store the device securely | Keep the device and e-liquid in a closed, labeled container out of reach and sight of children and pets. | Whenever the device is not in use | Nicotine exposure can be dangerous, especially for children. Do not store e-liquid in food or drink containers. | High |
| Handle spilled e-liquid | Wear disposable gloves if available, absorb the spill, place contaminated material in a sealed bag, and clean the surface. Seek medical advice after suspected ingestion or significant exposure. | Immediately after a spill | Never pour e-liquid into sinks, toilets, soil, or storm drains. Follow local hazardous-waste instructions. | High |
| Prepare a rechargeable battery for disposal | If safe to handle, separate the battery as instructed by the device manufacturer and cover exposed battery terminals with nonconductive tape. | Before transport to a collection point | Taping terminals helps reduce short-circuit risk during storage and transport. Do not puncture, crush, dismantle, or burn the battery. | Critical |
| Recycle batteries and devices | Take lithium-ion batteries and electronic devices to an approved battery, electronic-waste, or household hazardous-waste collection site. | When the device is no longer usable | Lithium-ion batteries should not be placed in household garbage or standard curbside recycling because they can cause fires in waste and recycling facilities. | High |
| Dispose of single-use devices | Do not burn, crush, dismantle, or place a complete disposable device in general waste. Use an authorized e-waste or hazardous-waste program. | When empty, damaged, or discarded | Disposable devices may contain both lithium batteries and residual nicotine liquid. Disposal requirements differ by local authority. | High |
| Transport damaged batteries | Do not transport a swollen, leaking, hot, smoking, or visibly damaged battery in a vehicle. Move away from flammable materials only if it is safe, and contact local emergency or waste authorities. | Immediately after damage is identified | A damaged lithium-ion battery can ignite without warning. Water exposure or unusual heat requires extra caution. | Critical |
| Follow local disposal rules | Check the local waste authority for accepted collection locations, packaging requirements, and rules for nicotine-containing liquid. | Before disposal | Battery, electronic-waste, and hazardous-waste regulations vary by location. Local instructions take priority. | Moderate |