Trade and service area as the place of occurrence of the external cause

This chapter permits the classification of environmental events and circumstances as the cause of injury, and other adverse effects. Where a code from this section is applicable, it is intended that it shall be used secondary to a code from another chapter of the Classification indicating the nature of the condition. Most often, the condition will be classifiable to Chapter 19, Injury, poisoning and certain other consequences of external causes (S00-T88). Other conditions that may be stated to be due to external causes are classified in Chapters I to XVIII. For these conditions, codes from Chapter 20 should be used to provide additional information as to the cause of the condition.

These categories may be used to provide supplementary information concerning causes of morbidity. They are not to be used for single-condition coding.

• The following category is for use, when relevant, to identify the place of occurrence of the external cause. Use in conjunction with an activity code.
• Place of occurrence should be recorded only at the initial encounter for treatment