Toxic effect of chlorine gas, undetermined, sequela

This code signifies a long-term or residual health effect resulting from a past exposure to chlorine gas, where the intent of the exposure (accidental, intentional self-harm, assault) is unknown. It indicates that the patient is currently experiencing symptoms or conditions directly attributable to the prior toxic inhalation.

Apply this code when documenting chronic respiratory issues, neurological sequelae, or other persistent health problems in a patient with a confirmed history of chlorine gas exposure, and the circumstances of that exposure were not determined. This is appropriate for follow-up visits addressing these ongoing, related conditions.

• Ensure documentation clearly links the current condition to the past chlorine gas exposure.
• Always code the specific manifestation of the sequela (e.g., chronic bronchitis, pulmonary fibrosis) first, followed by this sequela code.
• Do not use this code for acute toxic effects; it is exclusively for residual, long-term conditions.