Toxic effect of chlorine gas, assault, sequela

This code signifies the long-term or residual health problems resulting from a deliberate exposure to chlorine gas. These sequelae can manifest as chronic respiratory issues, persistent skin conditions, or other lasting organ damage that developed after the initial acute toxic event.

Apply this code when documenting conditions that are a direct consequence of a past chlorine gas poisoning, specifically when the exposure was determined to be an assault. This is appropriate for follow-up visits addressing chronic lung disease, neurological deficits, or other permanent impairments attributed to the toxic exposure.

• Ensure documentation clearly links the current condition to a past chlorine gas assault.
• This "S" (sequela) character indicates a late effect, not the acute poisoning itself.
• Always code the specific sequela (e.g., chronic bronchitis, asthma) first, followed by this external cause code.