The Occupational Injury and Illness Classification System (OIICS) has specific rules of selection for coding Nature, Part of Body Affected, Source of injury or illness, Secondary Source, and Event or Exposure. To correctly code injuries and illnesses and to understand OIICS coded data, it is important to understand the selection rules and orders of precedence. Note: the selection rules below are also available on the graphical code trees by clicking on the initial information symbol for each tree ( SELECTION RULES).

The nature of injury or illness identifies the principal physical characteristic(s) of the work-related injury or illness.

• Name the injury or illness indicated on the source document. Example: for strained back, choose Sprains, strains, tears.
• When two or more injuries or illnesses are indicated, and one is a sequela, aftereffect, complication due to medical treatment, or re-injury, choose the initial injury or illness. Example: If a laceration became infected developing into septicemia, choose Cuts, lacerations.
• When two or more injuries or illnesses are indicated and one is more severe than the other(s), select the more severe injury or illness. Example: If sprained finger and fractured wrist, choose Fractures.
  • When a single event or exposure produces an injury and transmits a disease simultaneously, and one is more severe than the other(s), select the more severe injury or disease. Example: If a needle stick produces a puncture wound and transmits an infectious disease, serum hepatitis, choose Serum hepatitis.
• When two or more injuries or illnesses are indicated but no one can be determined as being more severe than the others, select the appropriate multiple injuries or illnesses classification code. Example: for fractured and burned left leg, choose Fractures and burns.

The part of body affected identifies the part of the body directly affected by the previously identified nature of injury or illness.

• When the previously named injury or illness involves a single part, choose that part. Example: for fractured jaw, choose Jaw/chin.
• Traumatic Injuries and Disorders including internal burns and are generally coded to the external part or location, including specific locations for the mouth and back. Example: for lumbar sprain, choose Lumbar region of the Back. Exceptions are noted below.
  • When Intracranial Injury (including Concussion) is identified, choose Brain.
  • When the injury or illness affects an entire body system, rather than a particular part, name Body Systems. Example: for hypothermia, choose Body Systems.
• Internal body parts should be named when a disease, disorder, or condition originated at, or is limited to, that internal part. Example: for hepatitis, choose Liver; for lung cancer, choose Lung.
  • When the illness is cancer, choose the classification code for the original site of cancer.
• When the injury is an amputation, choose the classification code that represents the nearest part of body lost. Example: for amputation at knee, choose Lower leg(s).
• When the previously named injury or illness involves two or more parts within the same division, select the multiple classification code that includes those parts. Example: If lower leg, foot, and ankle are burned, choose Multiple lower extremities locations, n.e.c.
• When the previously named injury or illness involves parts from two or more divisions, select Multiple Body Parts. Example: for dislocated shoulder and fractured upper arm, choose Multiple Body Parts.

The source of injury or illness identifies the object, substance, bodily motion, or exposure which directly produced or inflicted the previously identified injury or illness.

• Name as the source of injury or illness the object, substance, element, or bodily motion which directly produced the injury or illness previously identified in the nature of injury or illness classification.
• If the injury or illness was inflicted by a specific part of a machine, tool, or vehicle, name the whole machine, tool, or vehicle as the source of injury except when:
  • the part separated from or was independent of the "whole";
  • the event is overexertion;
  • the injury was inflicted by an overhead powerline or the electrical cord of an appliance, tool, or machine;
  • the injury was inflicted by the floor of a vehicle in a non-transportation incident; or
  • the incident involved a tractor and agricultural equipment combination.

  In these instances, code that part as source.
• If the injury or illness was inflicted by a specific part of a structure (window, door, stairs) name that part as the source of injury.
• When an injury or illness was produced by a filled container, name the container, not the contents, as the source unless the injury or illness was directly inflicted by the contents, such as hot liquids or chemicals.
• Coding Bodily motion or position as the source of injury or illness:
  • Name Bodily motion or position as the source of injury or illness only when the injury resulted solely from the stress or strain induced by the free movement of the body or its parts (voluntary or involuntary), or from the assumption of a strained or unnatural body position.
  • Bodily motion or position includes injuries or illnesses resulting from reaching, turning, twisting, bending, walking, climbing, running, and from efforts to recover from a loss of equilibrium, provided that the loss of equilibrium does not result in a fall or in forcible contact with an object above the working surface.
  • Do not name Bodily motion or position as the source of injury or illness if the injury or illness resulted from any of the following:
    • falling
    • bumping into or striking an external object
    • nonrepetitive lifting, pushing, pulling, wielding, or throwing an external object
  • For injuries or illnesses in which either Repetitive motion or Sustained viewing is coded as the event, select bodily motion or position as the source of injury or illness.
• If, as the result of a transportation accident, a person who was in or on a vehicle or mobile equipment is injured, name the vehicle or mobile equipment as the source of injury.
• Selecting Source from multiple objects or substances:
  • When an injury results from forcible contact with two or more objects, either simultaneously or in rapid sequence, and it is impossible to determine which object directly produced the injury, select the source as follows:
    • When the choice is between a moving object and a stationary object, select the moving object. Example: If a person is struck by a moving vehicle and thrown against a post, name the vehicle as the source of injury.
    • When the choice is between two moving objects or between two stationary objects, select that which was contacted last. Example: If a person falls from an elevator, striking one or more objects in the course of his fall, but finally striking the floor, name the floor surface as the source of injury.
  • When an injury or illness results from two or more different objects or substances, all of which contributed to producing the injury or illness, select the source code as follows:
    • When there are two substances from the Chemical Division, select the appropriate "Multiple" code for that combination of chemicals.
    • When the two objects or substances are in the same Division, select the Divisional n.e.c. code for that Division. If they are in the same group within a division, select the group n.e.c.
    • When the two objects or substances are not in the same Division, use the code for Other sources, n.e.c.
• Select Weather and atmospheric conditions or geological events--Floods, Earthquakes, Avalanches--as the source of injury or illness when that is the only possible source identified.

  For example, if a worker sustained multiple injuries in an earthquake, and no other source could be determined, select earthquake as the source of injury. However, if an employee were driving in a rainstorm and had an automobile accident resulting in injury, select vehicle as the source.

The secondary source of injury or illness identifies the object, substance, or person that generated the source of injury or illness or that contributed to the event or exposure.

• Use the Source of Injury or Illness Classification Structure for coding secondary source of injury or illness.
• When the source of injury or illness is a moving object or harmful substance, name the machine, tool or equipment which generated the source or which propelled it. If none, name the work object from which the source originated, such as the steel plate from which a metal chip fell. Exceptions to this rule for Fires, Explosions, Assaults, and Transportation Accidents are noted below.

  When the source is an infectious agent, name the object or person through which the agent was transmitted.

• When involuntary motion leads to an injury or illness,--such as when a worker slips, trips, or is pushed or pulled into an object--name the object or substance, other than source, which contributed to the involuntary motion. Examples of objects and substances that could contribute to involuntary motion include clothing, jewelry, or cleaning cloths that pulled the worker into a machine, and substances such as ice, water, or grease that a worker slipped on.

  If no other contributing factor is named for incidents involving falls to lower levels, name the surface or object from which the worker fell.

• If the event is Fires or Explosions, name the flammable substance, other than the source, that ignited or exploded. If none is noted, name the machine, equipment, or object, other than the source, that caught fire or exploded.
• If the event is Assaults and Violent Acts, name the person, if not the source, who committed the act.
• If the event is Repetitive motion or Sustained viewing, name the machine, tool, or equipment that was being used or handled.
• If the event is a Transportation Accident involving a collision, name the vehicle, machine, or object with which the source collided.
• In the absence of a specific rule above, if two objects or substances contributed to an event, name the object, or substance which was not selected as the source. If more than two objects, substances, other than source, are involved, select:
  • powered or energized objects over nonpowered objects,
  • moving objects over nonmoving objects,
  • objects actively contributing to the event over passive objects.
• Select Weather and atmospheric conditions or geological events--Floods, Earthquakes, Avalanches--as the secondary source of injury or illness when that is the only possible secondary source identified.

  For example, if a worker sustained multiple injuries when struck by an object in an earthquake, select earthquake as the secondary source.

• If no object, substance, or person is determined to meet the definition and rules listed above, no secondary source is selected. Objects which inflict an injury, but which neither generated the source nor contributed to the event, should not be selected as the secondary source.

  For example, if a worker falls from a vehicle in a transportation incident and is injured when hitting the road surface, the road is not selected as the secondary source.

The event or exposure describes the manner in which the injury or illness was produced or inflicted by the source of injury or illness.

• When the injury or illness occurred as a result of contact with or exposure to an object or substance, select the event or exposure which best describes the manner in which that contact or exposure occurred.
  • The following events take precedence over other events or exposures:
    • Assaults and Violent Acts
    • Transportation Accidents
    • Fires
    • Explosions
    When two or more of these events occurred, select the first event listed above.
• When the injury or illness occurred as a result of bodily motion or position, select bodily reaction, repetitive motion or sustained viewing as the event or exposure code.

Injury @ Work

Coding Resources