Introduction to Industrial Hygiene MODULE 12

2©2006 TEEX 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©2006 TEEX Steps to Protect Employees  Anticipate potential hazards  Recognize potential hazards  Evaluate exposure and risk  Control exposure and risk  (Not just for health hazards)

4©2006 TEEX Hierarchy of Controls 1.Engineering controls: Remove hazard  Process change, Chemical substitution  Ventilation, Shielding, Guarding  Requires little or no employee action 2.Administrative controls: Manage exposure  Worker rotation, Procedures, Training  Trench shoring, Controlled access areas  Requires employee action

5©2006 TEEX Hierarchy of Controls 3.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©2006 TEEX 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

8©2006 TEEX 29 CFR Subpart Z  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©2006 TEEX 29 CFR Subpart Z  :  Specific regulations for individual substances including:  asbestos ( );  lead ( );  bloodborne pathogens ( ), and others  Hazard Communication

10©2006 TEEX (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©2006 TEEX (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©2006 TEEX (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/m 3 )

Subtitles & Transitions FOR EXAMPLE… 5 mg/M 3, Respirable fraction 15 mg/M 3, Total dust Particulates not otherwise regulated (PNOR) 1 ppmChlorine 50 ppmCarbon monoxide 1000 ppmAcetone Ceiling8-hr TWASubstance Table Z-1 Examples

14©2006 TEEX (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  Cadmium  Formaldehyde  Methylene chloride

15©2006 TEEX (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©2006 TEEX (b) - Table Z-2 Examples 10 min500 ppm300 ppm200 ppmToluene 5 min in any 3 hrs 600 ppm200 ppm100 ppmStyrene 10 min50 ppm20 ppmHydrogen sulfide 10 min50 ppm25 ppm10 ppmBenzene NotesPeakCeiling8-hr TWA Substance

17©2006 TEEX (c) - Table Z-3  8-hour TWA limits for forms of silica  Adopted from ACGIH TLVs  SiO 2 : basic component of sand, granite  Quartz: 2 nd most common mineral  Quartz sand (crystalline silica) used to fracture rock formations in wells  Silica in barite, lignite, and bentonite mud additives

18©2006 TEEX 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©2006 TEEX (c) - Table Z-3 5 mg/m 3 Respirable dust 15 mg/m 3 Nuisance dust 30mg/m 3 % Sio2 Amorphous 10mg/m 3 % Sio2 + 2 Crystalline Silica (Respirable fraction) PELSubstance

20©2006 TEEX (d) – Computation formulae  Time Weighted Average  E = (C 1  T 1 + C 2  T 2 + …)/total time  Total time used = 8 hours  Example in § (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 Interpretation

21©2006 TEEX (d) – Computation formulae  Exposure to Chemical Mixtures  E m = (C 1 /L 1 ) + (C 2 /L 2 ) + … + (C n /L n )  If E m > 1, employee is overexposed  Assumptions:  Chemicals’ effects are additive  Dose is proportional to C  T

22©2006 TEEX (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:

23©2006 TEEX Chemical-Specific Standards  Asbestos  Inorganic Arsenic  Lead  Chromium (VI) (revised 2006)  Cadmium  Benzene  Oil and gas drilling, production, servicing exempt  Formaldehyde

24©2006 TEEX 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©2006 TEEX 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©2006 TEEX Ionizing radiation  OSHA standards cover NORM and TENORM  Exposures must be kept within limits even if sources are natural

27©2006 TEEX 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©2006 TEEX 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

30©2006 TEEX 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©2006 TEEX 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©2006 TEEX 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©2006 TEEX 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©2006 TEEX Protective Measures  How are exposures to health hazards evaluated on your site?  How are they controlled?