By Brian Zaidman, Research Analyst, Research and Statistics, Minnesota Department of Labor & Industry
Reprinted from "Safety Lines: The Newsletter of Minnesota OSHA," Fall 2005.
Editor's note: This is the fifth installment of a series about using the OSHA Form 300 and summarizing its results. This
information is directed to people who are new to OSHA recordkeeping activities, to people who might be unfamiliar with the 2002
recordkeeping changes and to people who want to review their recordkeeping practices. This installment deals with classifying
cases as either injuries and illnesses.
This installment is about classifying cases as either
injuries or illnesses (OSHA log columns M1
through M6). Previous installments of this series
discussed basic OSHA recordkeeping
requirements; the process for classifying cases as
either days away from work, job transfer or
restriction, or other recordable cases; counting
days for days-away-from-work cases and cases
with job transfer or restriction; and describing
The formal title of the OSHA log is "Log of workrelated
injuries and illnesses." Employers classify
each case as either an injury or illness in columns
M1 through M6 (see figure below). Each case
needs to have a check in only one of the columns.
There is one column for injuries (M1), four
columns for specific illness types (M2 through M5)
and one column for any illness not included in the
other columns (M6). Employers are instructed to
check the injury or illness category that best fits
the circumstances of the case.
Column M1 — Injury
An injury is any wound or damage to the body
resulting from an event in the work environment.
Some common injury types are: cut, abrasion, fracture and burn. Sprain and strain injuries to
muscles, joints and connective tissues are
classified as injuries when they result from a slip,
trip, fall or other similar accidents.
Column M2—Skin diseases or disorders
Skin diseases or disorders are illnesses involving
the worker’s skin that are caused by work exposure
to chemicals, plants or other substances. Some
examples are: contact dermatitis, eczema and
rashes caused by primary irritants.
Column M3—Respiratory conditions
Respiratory conditions are illnesses associated
with breathing hazardous biological agents,
chemicals, dust, gases, vapors or fumes at work.
Some examples are: pneumonitis, tuberculosis,
occupational asthma, chronic obstructive
pulmonary disease (COPD), toxic inhalation
injury, such as metal fume fever, and chronic
Poisoning includes disorders evidenced by
abnormal concentrations of toxic substances in
blood, other tissues, other bodily fluids or the breath
that are caused by the ingestion or absorption of
toxic substances into the body. Some examples are:
poisoning by lead, mercury, cadmium or other
metals; poisoning by carbon monoxide, hydrogen
sulfide or other gases; poisoning by benzene, carbon
tetrachloride or other organic solvents; poisoning by
insecticide sprays, such as parathion or lead
arsenate; poisoning by other chemicals, such as
formaldehyde, plastics and resins.
Column M5—Hearing loss
Noise-induced hearing loss is defined as a change
in hearing threshold relative to the baseline
audiogram of an average of 10 decibels or more in
either ear at 2,000, 3,000 and 4,000 hertz, and the
employee’s total hearing level is 25 decibels or
more above audiometric zero in the same ear(s).
There is more detailed information about hearing
loss available on the OSHA recordkeeping Web
site at www.osha.gov/recordkeeping/hearinglossflowchart.pdf.
Column M6—All other occupational illnesses
Use this column only for illnesses that cannot be
classified in one of the other categories. Some
examples of other illnesses are: heatstroke, heat
exhaustion, freezing, frostbite, effects of welding
flash, anthrax and bloodborne pathogenic diseases,
such as AIDS, HIV, hepatitis B and hepatitis C.
If still unsure about the classification, employers
could use the longstanding distinction betweencases that result from instantaneous events or
exposures in the work environment (injuries) and
all other cases (illnesses).
Regardless of whether a case is considered an
injury or an illness, it is only a recordable case if it
results in death, loss of consciousness, days away
from work, restricted work activity or job transfer,
medical treatment beyond first aid or if it meets
any of the additional criteria (see the first article in
this series). For example, a work-related rash that
can be treated with a nonprescription ointment and
that does not result in any job restrictions or time
away from work is not a recordable case.
Remember to update the log when new
information about an illness or injury becomes
Federal OSHA recordkeeping resources
MNOSHA recordkeeping resources
MNOSHA WSC recordkeeping training
Survey of Occupational Injuries and Illnesses
Packet of recordkeeping forms, instructions
Booklet: Minnesota OSHA recordkeeping requirement