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B E ST P RACTICE S
S E CT I O N 4
S. Z. Mansdorf
I N D USTR IAL
H YG I E N E
LEAR N I NG OBJ ECTIVE S
Become familiar with the
definitions of industrial hygiene.
Know the five basic tenets of
industrial hygiene.
Become familiar with the best
practices for industrial hygiene
as categorized by the key elements of the practice of industrial
hygiene.
Understand the basis for inclusion of the listed programs,
approaches, and methods as
best practices.
INDUSTRIAL HYGIENE (also referred to as occupational hygiene)
has been defined as the science of protecting and enhancing the
health and safety of people at work and in their communities
(ABIH 2010). The practice of industrial hygiene (IH) is commonly described as the science and art devoted to the anticipation, recognition, evaluation, prevention, and control of those
environmental factors or stresses, arising in or from the workplace, which may cause sickness, impaired health and wellbeing, or significant discomfort among workers or the citizens
of the community (AIHA 2010). IH has been a recognized profession since the 1940s, allowing for the growth of best practices
in the profession as the science has developed. Best practice can
be defined as the best means to achieve a desired goal (i.e.,
health and safety). There are only a few technical references that
identify approaches, tools, or methods as being a best practice.
The majority of best practices listed in this chapter are those identified over 35 years of experience by the author in a variety of
sectors and roles. Where the tools and methods for best practice
are stated or implied as a best practice, they are referenced.
This chapter summarizes these best practices within the context
of five recognized aspects of IH (see Figure 1):
• anticipation
• recognition
• evaluation
• prevention
• control
A NTICI PATION
Anticipation is probably the most difficult aspect of industrial
hygiene. It certainly requires the most experience and technical
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Anticipation
• Reviewing all new chemicals and processes
(including significant modifications of processes)
in advance of their use
• Performing either a quantitative or qualitative
assessment annually (or a combination of the two)
of processes and procedures
• Using control banding, a best practice where there
is limited information or technical resources available
• Actively integrating industrial hygiene practices and
procedures into other related business processes
Recognition
• Establishing a file or database that contains all the
required (legal requirements) and recommended
practices for the substances and processes of concern
• Risk-ranking operations and establishing an
assessment or audit plan based on that ranking
Evaluation
• Having a justifiable exposure assessment strategy
• Documenting hazard evaluations in a detailed and
standardized way
Prevention
• Ensuring effective hazard communication
• Demonstrating the effectiveness of all health and
safety training
Control
• Following the hierarchy of controls
• Having an active product stewardship program
• Using a recognized safety and health management
system
FIG U R E 1. Best practices for industrial hygiene
knowledge (Mansdorf 1999a, Perkins 1997). Anticipation is essentially the estimation of exposure and response to one or more hazards. A simple example of
a solvent can illustrate the concept of anticipation.
To estimate the level of risk, the safety professional
would need to know the nature of the hazard (composition of the solvent of concern), the physical conditions (evaporation rates, room size, ventilation, and
work practices), the toxicity of the solvent (TLV, PEL,
and toxicological effects), protective measures (engineering controls, administrative controls, and PPE),
other potential hazards in the use of the solvent (e.g.,
fire or explosion), and other facts. Combining this
information with use conditions, one must estimate
the level of risk presented. It is also quite common to
have some of this information, but not all of it. This
further complicates the task of anticipating a potential
hazard. This is also why estimation (anticipation) of
the risk requires the most knowledge and experience.
The best practice in anticipation is the review of
all new chemicals and processes (including signifi-
cant modifications of processes) in advance of their
use (Hansen 2008). This practice can be done at the
organizational and local level. It should involve a
multidisciplinary team approach (typically involving safety, environmental, and engineering experts)
and can be based on various criteria to limit the
number of reviews. For chemicals, it could be limited to those of concern (health hazard, environmental hazard, or fire hazard). For processes, it could be
limited to those of most concern (high temperature,
high pressure, chemicals of concern, or physical hazards), or it might be based on the size of the project.
For potential high-hazard processes, best practice is
to use one of many available tools, such as the hazard and operability (HAZOP) approach. Best practice is to review all new chemicals and processes or
major process modifications for risk at the local level
(where it is used) and at the organizational level
(when they are to be implemented at multiple sites).
Another best practice is to perform a quantitative
or qualitative risk assessment of all processes and pro-
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Applied Science and Engineering: Best Practices
cedures (Wallace 2008). These assessments should be
performed annually. The ideal approach would be to
perform a quantitative assessment, as described in the
previous paragraph, for potential high-hazard situations and to perform a qualitative risk assessment
on a “wall-to-wall” basis annually. There are a number
of published approaches and tools for risk assessment
on both a quantitative and qualitative basis. Quantitative approaches include HAZOP, hazard analysis
(HAZAN), fault-tree analysis (FTA), failure mode
and effect analysis (FMEA), and others (Manuele 2008,
Cantrell and Clemens 2009). See also the section “Risk
Analysis and Hazard Control” in this Handbook, particularly the chapters “Systems and Process Safety” by
Hansen and “Basic Safety Engineering” by Mroszczyk.
These process safety procedures are usually limited to
high-risk operations. Quantitative approaches require
a significant level of effort and expertise, while qualitative approaches are relatively easy to perform and
usually involve workers more directly, since less technical skill in safety and health is needed. Qualitative
approaches include many variations on the common
theme of likelihood (frequency) and severity.
While there are a number of varying approaches
to qualitative risk assessments, the basic concept can
be described in six steps. The first step is the formation of a team to conduct the assessment. Ideally, this
would involve a technical expert or someone with
safety, industrial hygiene, or similar experience joined
by supervisors and workers that actually perform
the procedures in the areas being evaluated. An ideal
team would include at least five persons but not ex-
ceed ten members. Team composition can vary from
department or operational area, depending on the
breadth of knowledge of the workers in the procedures and processes in the areas under evaluation.
Step two is to collect and review all the procedures
and processes in the area under evaluation with the
team. At this stage, the team can also decide the
order of analysis. This can be based on product flow,
physical layout, or other factors. Stage three is identification of potential hazards. This usually involves
a walk-through of the area, brainstorming on what
could go wrong and the consequences, and a listing
of all the potential hazards considered, even though
potentially remote or unlikely. Step four is a more
systematic evaluation of each hazard, given in terms
of frequency, severity, and potential controls. Step
five is a mapping of frequency against severity (see
Tables 1 and 2) in a risk matrix (see Figure 2). Table
1, reflecting frequency of the hazard, can be altered
to fit the needs of the organization, as can Table 2,
TAB LE 1
Frequency of the Hazard
Description
Code
Definition
Frequent
A
once per week
Probable
B
once per year
Occasional
C
once per 3 years
Rare
D
once per 10 years
Improbable
E
once per 100 years
(Source: L'Oreal 2001)
TAB LE 2
Severity of the Hazard
Description
Level
Catastrophic
1
• Single or multiple deaths
• Severe and immediate operational
difficulties
• Site closure
Critical
2
Major
3
• Severe multiple injuries or potential
mortal disease
• Severe operational difficulties
• Severe reputational damage
• Severe injury or disease
• Loss of critical equipment
Minor
4
Negligible
5
FIG U R E 2. Risk-assessment matrix of frequency
and severity (Source: L'Oreal 2001)
(Source: L'Oreal 2001)
Definition
•
•
•
•
•
Minor injury or disease
Irritation
Loss of productivity
No injury or disease
No significant impact on production
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showing the severity of the hazard. The risk matrix
(Figure 2) is the outcome of the intersection of frequency and severity. This is shown as ranging from very
low (VL) to very high (VH), depending on the level of
acceptable risk for the workers and the organization.
One can also decide on the time constraints for lowering risk levels based on the risk. For example, a very
high risk (HR) would require immediate attention,
while a very low risk (LR) could be accepted. Low
(L) and medium (M) risks are those that commonly
dominate in most organizations.
Another approach is control banding—a variation
of the classical risk-assessment approach—which uses
chemical classes and the Global Harmonization System (GHS) for grouping and labeling chemicals. At
present, it is primarily used in Europe and based on the
current “R” phrases, which will be integrated into the
new GHS system under their registration, evaluation,
authorization, and restriction of chemicals (REACH)
requirements (Zalk and Nelson 2008). It places hazards
where the actual potential severity is not well known
into control bands, and control strategies are then defined based on these bands. While NIOSH (2009) and
others view this approach as having some limitations,
it has been successfully applied in a number of European countries, with the United Kingdom being one of
the leaders in its use. This practice is best applied to
chemical exposures where there is no occupational
exposure limit (OEL) or limited toxicological data, as
well as in situations where there is limited or no sampling or analytical method available. A good example
of the application of a control-banding approach is
found in nanotechnology, where the toxicological data
is limited and sampling and analysis difficult (Paik et
al. 2008). Control-banding applications with examples
can be found on the Health and Safety Executive (HSE)
Web site. Control banding is a best practice used where
limited information or technical resources are available
(NIOSH 2009, HSE n.d.).
Active integration of industrial hygiene practices
and procedures into other related business processes
is a best practice (Leibowitz 2003). It is listed in this section on anticipation since effective integration could be
considered a measure that anticipates hazards, although
it could also fit within the section on prevention as well.
SIDEBAR
An Example of the Six-Step Qualitative
Risk-Assessment Process
The qualitative risk-assessment process example scenario is a nonautomated hand-washing (cleaning) operation where the wash water is 160°F. This example
focuses on a single operation within a department and
a single risk to make it simple to follow.
Step 1: The team of six persons is formed. It includes
several workers from the area, the area supervisor, and
the team leader, who is a safety and health professional.
Step 2: In their walk-through survey, the team inspects the area where small irregular vessels are hand
washed, using a water hose and large sinks. The team
notes that it is a continuous operation with one person per shift assigned to this task. The team talks with
the washer and studies how the operation is performed. They also note that the washer wears a face
shield, apron, rubber gloves, and rubber boots.
Step 3: Among a list of ten possibilities for injury or
illness, the team’s analysis of the potential risks includes slips due to the wet floor and the potential for
workers to be splashed with hot water and/or get
soap in their eyes. They note that there have been some
previous incidents, but none of a serious nature.
Step 4: The team focuses on the hot-water burn potential first. They learn that body contact with water at
160°F can result in second- or third-degree burns in
less than one second of contact. They discuss all the
ways the water could scald the worker, such as by a
splash, by the hose breaking, by equipment malfunctioning, or by failure of the worker to wear the proper
equipment. They conclude that the potential probability of a splash occurring is once per year (for all three
shifts) and that its severity is in the “major” category.
They also note that the personal protective equipment
(PPE) might not fully protect the wearer as he or she
could be splashed on the arms, lower legs, head, or
back. Initially, they talk about potential additional controls, such as automating the process, providing more
protection for the worker, and using lower-temperature
water.
Step 5: The risk is mapped, using charts provided. As
discussed, the frequency is judged to be once per year,
which is “B” on the chart for frequency. The severity is
judged to be major, which is a “3” on the severity chart.
The intersection of a “B” frequency and “3” severity on