Toxic effect of carb monx from utility gas, acc, init

This code signifies an accidental poisoning due to carbon monoxide exposure specifically originating from utility gas. The patient is experiencing the initial symptoms or receiving initial treatment for this toxic effect.

Apply this code when a patient presents with carbon monoxide poisoning symptoms (e.g., headache, dizziness, nausea) and the source is identified as utility gas, such as from a malfunctioning furnace or stove. This code is appropriate for the first encounter for this specific poisoning event.

• Ensure the carbon monoxide source is explicitly documented as utility gas.
• Verify the intent is accidental; differentiate from self-harm or assault.
• Confirm this is the initial encounter for the poisoning; subsequent encounters will use a different seventh character.