Introduction to Industrial Hygiene

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Introduction to Industrial Hygiene

• MODULE 12

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What is Industrial Hygiene?

• Industrial hygiene is the science of
  anticipating, recognizing, evaluating, and
  controlling workplace conditions that may cause
  workers' injury or illness.
• Key factors
• Employee exposure to hazards
• Control for hazards to protect workers

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Steps to Protect Employees

• Anticipate potential hazards
• Recognize potential hazards
• Evaluate exposure and risk
• Control exposure and risk
• (Not just for health hazards)

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Hierarchy of Controls

• Engineering controls Remove hazard
• Process change, Chemical substitution
• Ventilation, Shielding, Guarding
• Requires little or no employee action
• Administrative controls Manage exposure
• Worker rotation, Procedures, Training
• Trench shoring, Controlled access areas
• Requires employee action

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Hierarchy of Controls

• Personal protective equipment (PPE)
• Respirators, Gloves, Boots, Clothing
• Fall protection equipment, Hard hats
• Requires individual employee action
• Last line of defense, behind engineering and
  administrative controls
• Addressed in 29 CFR 1910 Subpart I

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Chemical exposures in oil and gas operations

• What chemicals are used in oil and gas
  operations?
• How can employees be exposed?
• What toxic effects do these chemicals have?
• How can employees be protected from these effects?

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Toxic and Hazardous Substances

• 29 CFR Subpart Z

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29 CFR Subpart Z

• 1910.1000 Air Contaminants
• Includes Z tables worker exposure limits for
  specific listed substances
• Employee exposure cannot exceed limits
• Tables Z-1, Z-2, Z-3 each have their own
  requirements
• PEL Permissible Exposure Limit

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29 CFR Subpart Z

• 1910.1001-1096
• Specific regulations for individual substances
  including
• asbestos (1910.1001)
• lead (1910.1025)
• bloodborne pathogens (1910.1030), and others
• 1910.1200 Hazard Communication

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1910.1000(a) - Table Z-1

• Derived from 1968 ACGIH TLVs
• American Conference of Governmental Industrial
  Hygienists
• Threshold Limit Values
• Levels thought to cause no significant adverse
  health effects in the majority of the community

CHECK
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1910.1000(a) - Table Z-1

• Lists common workplace chemicals
• Two types of limits
• 8-hour Time Weighted Average (TWA) or
• Ceiling (C) limits
• Employee exposure shall at no time exceed a
  ceiling (C) exposure limit

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1910.1000(a) - Table Z-1

• 8-hour Time Weighted Averages (TWA)
• Employee exposure shall not exceed 8-hour TWA in
  any 8-hour work shift of a 40-hour work week
• Calculations illustrated in (d)
• Units
• Parts per million (ppm)
• Milligrams per cubic meter (mg/m3)

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Subtitles Transitions
Table Z-1 Examples

• FOR EXAMPLE

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1910.1000(b) - Table Z-2

• Adopted from ANSI standards (American National
  Standards Institute)
• Expanded standards developed for some of the
  substances found in Z-2, including
• Benzene 1910.1028
• Cadmium 1910.1027
• Formaldehyde 1910.1048
• Methylene chloride 1910.1052

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1910.1000(b) - Table Z-2

• Table Z-2 expresses exposure limits as
• 8-hour TWA
• Ceiling
• Peak
• If a substance has both ceiling and peak limits
  peak level never to be exceeded
• Exposure levels over the ceiling but under the
  peak must comply with margin notes in table
• TWA must still not be exceeded

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1910.1000(b) - Table Z-2 Examples
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1910.1000(c) - Table Z-3

• 8-hour TWA limits for forms of silica
• Adopted from ACGIH TLVs
• SiO2 basic component of sand, granite
• Quartz 2nd most common mineral
• Quartz sand (crystalline silica) used to fracture
  rock formations in wells
• Silica in barite, lignite, and bentonite mud
  additives

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Health Effects of Silica

• Silicosis
• Irreversible but preventable
• Most commonly associated with silica dust
• Other possible effects
• Lung cancer
• Some auto-immune diseases

(Scanning electron micrograph by William Jones,
Ph.D., compliments of OSHA)
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1910.1000(c) - Table Z-3
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1910.1000(d) Computation formulae

• Time Weighted Average
• E (C1?T1 C2?T2 )/total time
• Total time used 8 hours
• Example in 1910.1000(d)(1)(ii)
• What about different work schedules?
• Varies by chemical
• Most chemicals Worst 8 hours of shift
• Lead adjusted by hours worked
• Interpretation Foulke letter, 1997

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1910.1000(d) Computation formulae

• Exposure to Chemical Mixtures
• Em (C1/L1) (C2/L2) (Cn/Ln)
• If Em gt 1, employee is overexposed
• Assumptions
• Chemicals effects are additive
• Dose is proportional to C ? T

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1910.1000(e) To achieve compliance

• Administrative or engineering controls first
  wherever feasible
• When those are not feasible for full compliance
  protective equipment or other protective measures
• Equipment or technical measures must be approved
  by competent industrial hygienist or qualified
  person
• Respirators 1910.134

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Chemical-Specific Standards

• 1910.1001 Asbestos
• 1910.1018 Inorganic Arsenic
• 1910.1025 Lead
• 1910.1026 Chromium (VI) (revised 2006)
• 1910.1027 Cadmium
• 1910.1028 Benzene
• Oil and gas drilling, production, servicing
  exempt
• 1910.1029 Formaldehyde

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1910.1020 Access to employee exposure and medical
records

• Employees, representatives, and OSHA have right
  of access
• Preserved for 30 years, with exceptions
• Employee consent for medical records
• OSHA access order posted if identifiable
• Trade secrets
• Employee information

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1910.1030 Bloodborne Pathogens

• Occupational exposure
• Reasonably anticipated skin, eye, mucous
  membrane, or parenteral contact
• With blood or other potentially infectious
  materials (OPIM) e.g. certain body fluids, tissues

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1910.1096 Ionizing radiation

• OSHA standards cover NORM and TENORM
• Exposures must be kept within limits even if
  sources are natural

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1910.1201 Retention of DOT markings, placards and
labels

• Retain markings on packages received until clean
  enough to remove hazard
• Freight container or vehicle retains placards
  until materials removed enough
• Readily visible
• Non-bulk packages not to be reshipped Hazard
  Communication labels OK

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1910.1450 Hazardous chemicals in laboratories

• For laboratory use only
• Supersedes other standards in Subpart Z except
  
• PELs
• Prohibition of eye and skin contact
• Exposure monitoring and medical surveillance for
  those over action levels

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Protective Measures

• Other Standards and

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General Duty Clause

• Recognized hazards may be cited
• If there is no PEL
• Consensus or proprietary standards
• ANSI, ACGIH, AIHA
• Industry Best Practices
• Manufacturer Recommendations (MSDS)

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Biological Hazards

• Potentially infectious material exposure
• Contagious diseases e.g. influenza
• Vector-borne diseases e.g. Malaria, Lyme disease
• Fungi e.g. mold, spores
• Toxins e.g. endotoxin
• Allergens / sensitizers e.g. pollen, red cedar

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Physical and Radiological Hazards

• Heat or cold (General Duty Clause)
• Vibration (General Duty Clause)
• Noise (1910 Subpart G)
• Non-ionizing radiation (electromagnetic, light)
  (1910 Subpart G)
• Ionizing radiation

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Other Standards

• 29 CFR 1926 Subpart D Occupational Health and
  Environmental Controls
• Construction operations only
• API RP 54
• Noise rules allow for 12 hour shifts
• Handling drilling fluid chemicals and additives

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Protective Measures

• How are exposures to health hazards evaluated on
  your site?
• How are they controlled?