ICD-10-CM > S00-T88 > T51-T65 > T59 > T59.4 > T59.4X > T59.4X4 T59.4X4 Toxic effect of chlorine gas, undetermined Non-Billable/Non-Specific Codes T59.4X4A..., initial encounterT59.4X4D..., subsequent encounterT59.4X4S..., sequela