Introduction
to Industrial Hygiene
Industrial hygiene is an area of specialization
in the field of industrial safety and health that is concerned with predicting,
recognizing, assessing, controlling, and preventing environmental stressors in
the workplace that can cause sickness or serious discomfort to workers. An
environmental stressor is any factor in the workplace that can cause enough
discomfort to result in lost time or illness.
The environmental stressors on which industrial
hygiene focuses can be divided into the four broad categories: chemical,
physical, biological, and ergonomic hazards.
Figure 1.
Environmental stressors
Chemical Hazards:
Typical chemical hazards include vapors, gases,
mist, fumes and dusts. Chemical hazards are generally inhaled or absorbed
through the skin or both.
People are exposed to a variety of substances
every day in the home and at work. Detergents, paints, paint remover, cleaning
solvents, antifreeze are some examples. Most substances with which we interact
are not dangerous in small amounts or limited exposure. However, high level of
exposure to certain substances in high concentrations can be dangerous. Levels
of exposure and concentrations, as well as how we interact with substances,
help to determine how hazardous substances are. In addition, some substances
used frequently in certain industrial settings can explode.
Employees must be warned of chemical hazards by
labels on containers or material safety data sheets (MSDS). Material Safety
Data Sheets are special documents that summarize all pertinent information
about a specific chemical. Occupational Safety and Health Act (OSHAct) requires that chemical suppliers provide users with
an MSDS for each chemical covered by the OSHA standard, known as "Hazard
Communication Standard".
OSHA standards also include the acceptable
levels of exposures to chemicals at the workplace. Industrial Hygienists are
required to monitor these exposure levels and select proper type of personal
protective equipment when the permissible levels of exposure are exceeded.
Physical Hazards:
Physical hazards include noise, vibration, extremes of temperature, improper illumination and excessive
radiation which can be electromagnetic or ionizing.
Acceptable levels of noise have been
recommended by OSHA, NIOSH (National Institute for Occupational Safety and
Health) and EPA (Environmental Protection Agency). An industrial hygienist is
responsible for monitoring the noise level at the work place and recommend
proper protection when the noise exposure levels exceed the OSHA permissible
levels.
Radiation hazards are increasingly prevalent in
the age of high technology. In the category of ionizing radiation, safety and
health professionals are concerned with five types of radiation, which are
alpha (a ),
beta (b ), gamma (g ) and neutron radiation. Alpha radiation is
the least penetrating, making shielding simple, whereas the other types of
radiation require more strict shielding requirements. Nonionizing
or electromagnetic wave radiation includes ultraviolet, infrared, microwave and
laser radiation. The greatest risk for nonionizing
radiation in the workplace comes from lasers.
Biological Hazards:
Biological hazards come from molds, fungi,
bacteria, and insects. Bacteria may be introduced into the workplace through
sewage, food waste, water, or insects. Biological hazards from various
biological organisms can lead to disease in workers. The outbreak of what has
come to be known as Legionnaire's disease is an example of what can result from
biological hazards. This disease first surfaced at a convention where numerous
participants became sick and soon died. The cause was eventually tracked back
to bacteria that grew in the cooling /air-moving systems serving the convention
center. That bacteria has been since named Legionnella.
Ergonomic Hazards:
Ergonomic hazards are conditions that require
unnatural postures and unnatural movement. The human body can endure limited
amounts of unnatural postures or motions. However, repeated exposure to such
conditions can lead to physical stress and injury. Design of tools,
workstations, and jobs can lead to or prevent ergonomic hazards. Repetitive
Strain Injury (RSI) is an example for ergonomic hazards. RSI is a term that
covers a number of cumulative trauma disorders (CTDs)
caused by forceful or awkward hand movements repeated frequently over time.
Other aggravating factors include poor posture, an improperly designed
workstation, and job stress. RSIs occur to the
muscles, nerves, and tendons of the hands, arms, shoulders, and neck.
OSHA and Industrial
Hygiene:
The Occupational Safety and Health
Administration (OSHA) is part of Department of Labor. OSHA develops and
implements standards and regulations, conducts inspections and investigations
to ensure compliance, issues citations and proposes penalties for violations.
It also provides assistance to employers in complying with standards and
regulations through consultations, training programs and publications.
The Occupational safety and Health Act (OSHAct )
sets forth the following requirements relating to industrial hygiene:
Use of
warning labels and other means to make employees aware of potential hazards,
symptoms of exposure, precautions, and emergency treatment.
Prescriptions
of appropriate personal protective equipment and other technological preventive
measures.
Provision of
medical tests to determine the effect on employees of exposure to environmental
stressors.
Maintenance
of accurate records of employee exposures to environmental stressors that are
required to be measured or monitored. Making monitoring tests and
measurement activities open to the observation of employees.
Making records of
monitoring tests and measurement activities available to employees upon
request.
Notification
of employees who have been exposed to environmental stressors at a level beyond
the recommended threshold and corrective action being taken.
NIOSH and Industrial
Hygiene:
The National Institute for Occupational safety
and Health (NIOSH) is part of the department of Health and Human Services. This
agency is important to industrial hygiene professionals. The main focus of the
agency's research is on toxicity levels and human tolerance levels of hazardous
substances. NIOSH prepares recommendations for OSHA standards dealing with
hazardous substances, and NIOSH studies are made
available to employers.
The areas of research of NIOSH are conducted by
the divisions of Biomedical and Behavioral Science; Respiratory Disease
Studies; Surveillance, Hazard Evaluations, and Field Studies and Training and
Manpower Development. The results of these divisions' studies and their
continuously updated lists of toxic materials and recommended tolerance levels
are extremely helpful to industrial hygienists concerned with keeping the
workplace safe.
Links
Occupational Safety and Health Administration (OSHA)
National Institute for Occupational Health and Safety (NIOSH)
Last Update:
Prepared by: Serdar
Z. Elgun