Introduction to Industrial Hygiene

1. Introduction to Industrial Hygiene MODULE 12

2. 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

3. Steps to Protect Employees • Anticipate potential hazards • Recognize potential hazards • Evaluate exposure and risk • Control exposure and risk • (Not just for health hazards)

4. 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

5. 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

6. 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?

7. Toxic and Hazardous Substances 29 CFR Subpart Z

8. 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

9. 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

10. 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

11. 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

12. 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)

13. Substance 8-hr TWA Ceiling Acetone 1000 ppm Carbon monoxide 50 ppm Chlorine 1 ppm Particulates not otherwise regulated (PNOR) 15 mg/M3, Total dust 5 mg/M3, Respirable fraction Table Z-1 Examples Subtitles & Transitions FOR EXAMPLE…

14. 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

15. 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

16. 1910.1000(b) - Table Z-2 Examples Substance 8-hr TWA Ceiling Peak Notes Benzene 10 ppm 25 ppm 50 ppm 10 min Hydrogen sulfide 20 ppm 50 ppm 10 min Styrene 100 ppm 200 ppm 600 ppm 5 min in any 3 hrs Toluene 200 ppm 300 ppm 500 ppm 10 min

17. 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

18. 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)

19. 1910.1000(c) - Table Z-3 Substance PEL Crystalline Silica (Respirable fraction) • 10mg/m3 % Sio2 + 2 • 30mg/m3 % Sio2 Amorphous Nuisance dust • 15 mg/m3 Respirable dust • 5 mg/m3

20. 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

21. 1910.1000(d) – Computation formulae • Exposure to Chemical Mixtures • Em = (C1/L1) + (C2/L2) + … + (Cn/Ln) • If Em > 1, employee is overexposed • Assumptions: • Chemicals’ effects are additive • Dose is proportional to C  T

22. 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

23. 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

24. 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

25. 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

26. 1910.1096 Ionizing radiation • OSHA standards cover NORM and TENORM • Exposures must be kept within limits even if sources are natural

27. 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

28. 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

29. Protective Measures Other Standards and

30. 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)

31. 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

32. 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

33. 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

34. Protective Measures • How are exposures to health hazards evaluated on your site? • How are they controlled?