Farm workers are at high risk of scalping and other
severe injuries when they work near farm machinery with
inadequately guarded drivelines or shafts driven by
power take-offs (PTOs).
Alert describes five cases of persons who were scalped when
their hair became entangled around the inadequately guarded
rotating drivelines or shaft of farm machinery driven by power
takeoffs (PTOs). Such entanglement of hair, clothing, or body
parts kills and injures many farm workers each year. The recommendations
In this Alert will help prevent these entanglement Injuries
and deaths. The National Institute for Occupational Safety
and Health (NIOSH) therefore requests the assistance of county
extension agents, editors of trade journals, agricultural
associations, and equipment manufacturers in bringing these
recommendations to the attention of farm owners, workers,
and family members at risk.
Several surveillance systems collect data on farm-related entanglement
injuries: the NIOSH National Traumatic Occupational Fatalities
(NTOF) Surveillance System, the National Electronic injury Surveillance
System (NEISS) of the U.S. Consumer Product Safety Commission
(CPSC), and the NIOSH- funded Agricultural Health Nurse Program
(AHNP) of New York State.
from the NTOF Surveillance System indicate that at least 346
farm workers aged 16 or older died from farm-related entanglement
injuries between 1980 and 1989; 112 of those deaths were caused
by entanglement in PTO-driven drivelines and shafts of farm
machinery [NIOSH 1993].
10,000 nonfatal entanglement injuries also occurred on farms
between 1982 and 1986 [CPSC 1987]. Of these injuries, 864
included the loss of a body part.
1991, the AHNP of New York State reported a case of a woman
who was scalped when her hair became entangled around the
secondary driveline of a hay bailer. Further investigation
revealed that four similar incidents had occurred in New York
State between 1973 and 1991. All five cases are described
in detail in the Case Reports section of this Alert.
Since 1976, OSHA regulations have required that the shafts and drivelines on all farm equipment be "guarded to protect against employee contact" [29 CFRT 1928.57 (b)(1)(iii)]. These regulations apply to all farm machinery, even that manufactured before 1976. The incidents described here occurred where the OSHA regulations are not enforceable-on farms that employ fewer than 11 full-time workers.
The American Society of Agricultural Engineers (ASAE) publishes voluntary standards for the safety (ASAE S318.10) and guarding (ASAE S493) of agricultural equipment [ASAE 1992b,c]. For further information about these standards, contact the ASAE at 2950 Niles Rd., St. Joseph, MI 490859659; telephone,(616) 429-0300.
The New York AHNP and the NIOSH Division of Safety Research
recently investigated five scalping incidents involving five
female farm workers or farm family members. Each woman was scalped
totally or partially when her hair became entangled around the
rotating secondary driveline of hay baling equipment (see Figure
In July 1991, a 47-year-old woman was baling hay on a windy day. After positioning the tractor throttle on idle but not disengaging the PTO, she dismounted and walked toward the back of the tractor past a rotating secondary driveline that powered the bale thrower. This driveline was located 4 feet above ground and was guarded by a tunnel guard (i.e., an inverted U-shaped guard) that left the underside of the driveline exposed. While the woman was at the rear of the baler, her hair (which wa reportedly tied back, covered with a bandanna, and tucked inside her shirt) became entangled around the driveline. The rotating driveline tore her entire scalp from her head. These injuries required extensive skin grafting and left her permanently disfigured [CDC 1992].
1990, a 30-year-old woman was baling hay with a recently purchased
used baler. After recognizing a problem with the bale tension,
she reduced the tractor speed to idle, dismounted from the
tractor, and walked toward the rear of the baler past the
driveline of the bale thrower. This secondary driveline was
shielded with a tunnel guard. As the woman bent over to adjust
the bale tension, her hair (which was tied back in a long
ponytail) became entangled around the driveline and her entire scalp was torn from her head [CDC 1992].
In July 1981, a 42-year-old woman was leaning against a tunnel guard for the rotating driveline that powered the bale thrower on a hay baler. As she bent over to evaluate a problem with the machinery, her shoulder-length hair became entangled around the secondary driveline, and her right ear and the right side of her scalp were torn from her head [CDC 1992].
In June 1976, a 42-year-old woman who was baling hay walked toward the rear of the baler past the rotating secondary driveline of the bale thrower. The driveline was guarded by a tunnel guard. Her hair (reportedly tied in a bun) became entangled around the driveline and her entire scalp was torn from her head. She also received serious facial injuries that required extensive reconstructive surgery [CDC 1992].
In June 1973, a 12-year-old girl was walking in a hayfield while her father baled hay. Her father slowed the tractor to an idle and asked the girl to check the bale counter to see how many bales had been made. To check the counter, the girl lowered her head under a rotating, tunnel-guarded driveline that powered the bale thrower. The girl's ponytail became entangled around the driveshaft, causing the ponytail and the attached skin to be torn from her head [Roerig 1991].
All five incidents described in this Alert involved inadequately
guarded drivelines and victims who were standing or walking
near rotating drivelines.
The inadequately guarded drivelines involved in the five incidents described here were guarded by inverted U-shaped tunnel guards that did not completely enclose the drivelines (see Figure 1). Initially, the rotating driveline was thought to have created enough air current to have drawn the hair of the victim onto it. However, an investigation of Case No. 1 showed that the rotating driveline produced no measurable air currents. Direct contact with the shaft or driveline could nonetheless have occurred through the open portion of the U shape. In addition, the drivelines were located approximately 4 feet above the ground, limiting visibility of the hazard. Two of the victims stated that they were unaware of the exposed rotating driveline underneath the shield.
inadequately guarded drivelines involved in the five incidents
described here were associated with Models 54A, 54B, 58, and
62 of a bale thrower manufactured by New Holland before 1976
[CDC 1992]. Various types of machinery produced by other manufacturers
may also have U-shaped guards, especially equipment manufactured
safety shield kit has been available from the manufacturer
for the older New Holland balers since 1976. The kit contains
two plastic guards for the driveline, a safety decal, and
throwers currently manufactured by Ford-New Holland (formerly
New Holland) are equipped with a guard that fully encloses
the driveline. However, the older models can remain in service
for many years-even decades. A farmer purchasing used machinery
would probably be unaware of any retrofit guards available
from the manufacturer. Therefore, many farmers may be using
inadequately guarded machines, as illustrated in this Alert.
or Walking Near Rotating Drivelines
The most important safety rule for farmers to heed is to disengage the PTO and turn off the tractor before leaving the tractor seat or approaching a driveline. This rule is supported by the results of a study showing that many entanglement injuries occur when the farm machinery is stationary and the PTO is engaged [Sell 1984].
operating manuals for farm machinery with PTO-driven shafts
or drivelines warn users to disengage the PTO and turn off
the tractor ignition before performing any maintenance or
adjustments on the machinery. Warning labels containing this
information are also strategically placed on some farm machinery.
Unfortunately, operating manuals may not be available for
used machinery, and warnings may not be followed. Some farmers
believe that machinery must be operating for them to perform
proper maintenance or adjustments. However, if the PTO is engaged
and the tractor ignition is left on during maintenance, inspection,
or other tasks, both the operator and anyone near the machinery
are exposed to serious entanglement hazards.
The scalping incidents described in this Alert represent only
one type of entanglement injury involving PTO-driven, rotating
shafts or drivelines. Many other serious injuries, amputations,
and deaths result each year when farm workers use inadequately
guarded machinery. These injuries and deaths could be prevented
if inadequately guarded machines were provided with retrofit
guards and if farm workers always disengaged PTOs and turned
off ignitions before performing maintenance and other task .
NIOSH recommends that farm owners and workers take the following measures to prevent injuries from primary and secondary drivelines and other PTO-driven shafts.
disengage the PTO and turn off the tractor ignition before
leaving the tractor seat and approaching the driveline.
not perform maintenance or adjustments until both the driveline
and the machinery have completely stopped moving.
the manufacturer's instructions whenever maintenance or
adjustments are performed on any farm machinery.
anyone who might come near an operating PTO about the entanglement
all farm family children and untrained adolescents never
to approach, operate, or perform maintenance on PTO driven
not wear loose-fitting clothing or jewelry near operating
back or otherwise secure loose hair, but be aware that even
short or tied-back hair may become entangled in moving equipment.
of PTO-driven Equipment
PTO-driven equipment components (such as drivelines, drive
chains, or gears) on all farm machinery.
all PTO-driven farm machinery for U-shaped tunnel guards
and replace them with retrofit guards recommended by the
manufacturer or dealer.
prevent installation of an inadequate guard, consult with
the manufacturer or dealer before fitting a machine with
any type of guard.
machine guarding in compliance with OSHA regulations [29
CFR 1928.57], as follows:
must prevent entry into the point of operation by hands
or fingers reaching through, over, under, or around
must not create additional hazards (for example, with
sharp edges or protruding parts).
must not interfere with work tasks.
must create no pinch point between the guard and moving
possibility of guard misuse or removal must be minimized
through the use of guards that the operator cannot remove
or bypass easily.
must not interfere with the inspection, servicing, or
cleaning of the machine.
must conform with existing standards, designs, and construction.
all machine guarding according to the manufacturer's most
current specifications. If these are not readily available,
seek assistance from equipment dealers, county extension
agents, or other agricultural safety specialists.
periodically with manufacturers, equipment dealers, and
county extension agents for updated information about retrofit
guards for PTOS.
The principal contributors to this Alert were Virgil Casini
and Karl Snyder, Ph.D., Division of Safety Research, NIOSH.
NIOSH also acknowledges the New York AHNP for providing the
incident data used in this Alert and for assisting NIOSH in
the investigations described here.
questions, or requests for additional information should be
directed to Dr. Alfred Amendola, Acting Director, Division
of Safety Research, National Institute for Occupational Safety
and Health, 1095 Willowdale Road, Morgantown, WV 26505-2888;
telephone, (304) 284-5700.
further information about farm safety or other workplace safety
and health hazards, call 1-800-35-NIOSH (1-800-356-4674).
appreciate your assistance in protecting the lives of U.S.
Rosenstock, M.D., M.P.H.
National Institute for
Safety and Health
for Disease Control and Prevention
[1992a]. ASAE standard: ASAE S207.11. Operating requirements
for tractors and power take-off driven implements. St. Joseph,
MI: American Society of Agricultural Engineers.
[1992b]. ASAE standard: ASAE S318.10. Safety for agricultural
equipment. St. Joseph, MI: American Society of Agricultural
Engineers. St. Joseph, MI: American Society of Agricultural
[1992c]. ASAE standard: ASAE S493. Guarding for agricultural
equipment. St. Joseph, MI: American Society of Agricultural
Code of Federal regulations. Washington, DC: U.S. Government
Printing Office, Office of the Federal Register.
(Centers for Disease Control and Prevention) . Scalping
incidents involving balers-New York. MMWR41(27):489-491.
. National electronic injury surveillance system,
May 1981-April 1987. Washington, DC: U.S. Consumer Product
. National traumatic occupational fatalities surveillance
system. Morgantown, WV: U.S. Department of Health and Human
Services, Public Health Service, Centers for Disease Control
and Prevention, National Institute for Occupational Safety
DS . Personal communication with D.S. Roerig, Agricultural
Occupational Health Nurse, New York State Department of
WE . The nature of power take-off accidents [Thesis].
Lafayette, IN: Purdue University.
Publication #: 94-105
Publication date: June 1994.
Institute of Occupational Safety and Health, 200 Independence
Avenue, SW, Washington, DC, 20201. Phone (800) 356-4674.
Mention of the name of any company or product does not constitute
endorsement by the National Institute for Occupational Safety
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