Introduction to Industrial Hygiene MODULE 12

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

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

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

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

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?

Toxic and Hazardous Substances 29 CFR Subpart Z

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

29 CFR Subpart Z 1910.1001-1096: 1910.1200 Hazard Communication Specific regulations for individual substances including: asbestos (1910.1001); lead (1910.1025); bloodborne pathogens (1910.1030), and others 1910.1200 Hazard Communication

CHECK 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

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

1910.1000(a) - Table Z-1 8-hour Time Weighted Averages (TWA) Units: 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)

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

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

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

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

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

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)

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

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

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

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

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

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

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

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

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

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

Protective Measures Other Standards and

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)

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

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

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

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