Toxic effect of gases, fumes and vapors, undet, sequela

This code signifies a long-term or residual health problem resulting from exposure to a specified gas, fume, or vapor, where the intent of the exposure (e.g., accidental, intentional self-harm) could not be determined. These sequelae represent the lasting effects after the acute phase of the toxic exposure has passed.

Apply this code when documenting chronic respiratory issues, neurological deficits, or other persistent organ damage directly attributable to a past exposure to a specific gas, fume, or vapor. This is appropriate when the medical record clearly indicates the exposure occurred, but the circumstances surrounding the exposure remain unknown or unclarified.

• Always assign a sequela code (ending in 'S') for conditions that are residual effects of a past toxic event.
• Ensure documentation specifies the type of gas, fume, or vapor if known, to support the "other specified" category.
• This code requires documentation that the intent of the exposure is "undetermined." If intent is known, a different 7th character (A, D, P) would be used.