Exposures To Hexavalent Chromium In The Utility Industry

Exposures toHexavalent Chromiumin the Utility IndustryJeff Gilbert, CIHE.ON U.S. LLCEdison Electric InstituteSafety & Health Committee ConferenceApril 30, 2008

Louis-NicholasLi Ni h l VauquelinVlic. 1797

Sources of Exposure within the UtilityI d tIndustry Grinding of stainless steels and otherchromium containing or coated metals Flyash CCA-treated wood (poles & coolingttowers)) Welding & thermal cutting of stainlesssteels and other chromium containing orcoated metals

Exposure Monitoring Pre-2006Pre 2006 – modified NIOSH 7300 Method(ICPMS) or NIOSH Method7600/7604/7605 Current – OSHA ID 215 (ICP)– SamplesSl collectedll t d on PVC filtersfilt– To lab within 8 days of sampling Wipe sampling (W4001)– Target concentration 0.050 µ/100 cm2

Air Monitoring Data Form – Hexavalent ChromiumAir Monitoring Data Form – Hexavalent ChromiumLocation: Date: Sampler: Pump #Sample Type: PersonalSample Media: PVCEmployee Information: (Name, employee id#, Job title, respirator & filter type, personal protective equipment used)Task Description: (use back of this form if more space is needed)Tools (grinder, type of welder – stick, TIG, MIG, etc.):Base Metal: Consumables (type of welding rod/wire, carrier gases):Number of Employees involved with task:Description of Space (size, shape, etc.):Work orientation (vertical/horizontal surface? overhead/waist height/below waist,waist etc):Is the work performed in a confined space? If yes, what is the permit number/identifier?Controls Used (air horns, capture hoods, other?):Direction of Airflow (from behind welder, in welder’s face, etc.):Sample #AnalyteTime OnTimeOffMinutesPre-calibration Flow rate:FlowRateVolumeCommentsPost-calibration Flow Rate:The sample cassette must be positioned so that it is under the welding hood when the hood is lowered. This can be achieved bytaping or clipping the cassette to the inside of the hood near the cheekcheek. If the hood is removedremoved, tape or clip the cassette to theemployee’s lapel or outer clothing shoulder area. Care should be taken to avoid crimping the hose or blocking the inlet to thecassette.

Objective dataObjectivejdata means information such as airmonitoring data from industry-wide surveys orcalculations based on the composition orchemical and physical properties of a substancedemonstrating the employee exposure tochromium (VI) associated with a particularproduct or material or a specific processprocess,operation, or activity. The data must reflectworkplace conditions closely resembling theprocesses types of materialprocesses,material, control methodsmethods,work practices, and environmental conditions inthe employer's current operations.

OSHA s Letter of InterpretationOSHA’sto Mr. Douglas Greenhaus, NationalAutomobile Dealers Association, et al. –11/14/2006Main emphasis: Accuracy of data collected Level of detail of data collected ReproducibilityRd ibilit off ththe resultslt ((proven bbyeach user)

Grinding“The U.S. Department of Labor’s Occupational Safety andH lth AdHealthAdministrationi i t ti (OSHA) iis publishingbli hi a minoriamendment in today’s Federal Register to thecompliance date provision of its hexavalent chromiumstandard for general industryindustry. The amendment is part ofa settlement agreement with the Surface FinishingIndustry Council (SFIC), Public Citizen Health ResearchGroup, and the United Steel, Paper and Forestry,Rubber, Manufacturing, Energy, Allied Industrial andService Workers International Union. The agreementresolves a legal challenge by the SFIC to OSHA’shhexavalentl t chromiumhistandard.”t d d”National News Release 06-1906-NATOctober 30, 2006

Grinding“6.6. Dust ControlBetter housekeeping. Chrome dust that comesoff pproducts that are ppolished or ggrinded isactually elemental chromium, not hexavalentchromium, so polishing and grinding contributelittle to airborne hexavalent chromiumlevels. However, Companies should use goodhousekeeping practicespractices, including wet moppingmopping,and wet wipe downs, to reduce the amount ofdust presentpresent.”

Grinding Number of Samples 3*3 Highest Exposure 0.323 µg/M3 NumberN b off sampleslbelow detection limit 2(both were short duration samples – 1 hour or less)*Note: work involving both grinding and welding are notincluded in this data set.

Flyash Exposures Number of Samples 36 Highest Exposure 0.44 µg/M3 15 samplesl bbelowlddetectiont ti lilimititComments: total of 4 samples above0 2 µg/M3, all in “very0.2very dusty”dusty environment

Cutting &/or Drilling Holes into UtilityP lPoles Number of Samples 6 Highest Exposure 0.062 µg/M3Comments: Wooden Cooling Towers?

Coal Handling Number of Samples 13 Highest Exposure 0.12 µg/M3Comments: Range of other 12 samples was 00.0101 to 00.0505 µg/M3

Work Activities Not InvolvingA ti i t d EAnticipatedExposures‘Normal’Normal Operations– Operators, Auxiliary Operators Number of Samples 39 Highest Exposure 0.12 µg/M3 23 samples below detection limit– Maintenance Personnel (no welding, etc.) Number of Samples 50Highest Exposure 0.38 µg/M317 samples below detection limitOnly 2 samples above 0.1 µg/M3, both in precipitators

Welding & Thermal CuttingTypes of Steel– Mild steel– Chromalloy– Nickel-Chromium steels– Chromium steels– Stainless steels

Sampling Welders

Welding & Thermal Cutting Total SamplespCollectedSMAWGMAWGMAW PGMAW-PGTAWCarbon Arc Cutting/PACHardfacingWeldinge d g ((notot dedefineded & mixed)ed) 227 55 5 4 136 16 10 21Information gathered from several sources within the Utility Industry

Range of Exposure Levels SMAWGMAW**GMAW-PGTAWACAC/PACH d ffacingHardiWelding not defined ND* to 47 μgμg/M3 0.05 to 0.64 μg/M3 ND to 13 μg/M3 ND to 6.4 μg/M3 ND to 48.2 9 tto 220 μg/M/M3 0.018 to 0.64 μg/M3* ND none detected** All were carbon steels

Factors Influencing Exposure Configuration of WorkspaceUse of Ventilation ControlsType of WeldingBase & Consumable Metals UsedN b off WeldersNumberW ldWorkingW ki iin SSame AAreaWork/Worker OrientationDuration of WorkWhere the Work is Performed

Controlling Exposures HoodFFumeextractiont ti gunDown draft or back draft tableDil ti ventilationDilutiontil tiHousekeeping & HygieneRespiratory Protection

Welding & Cutting FumeJob Aid

Welding and Cutting Fume Decision Job AidThis job aid has been designed to assist employees in the proper selection of fume controls(ventilation and/or respiratory protection) for welding and cutting operations.For steps 1 through 4, select the Safety Rating that matches the work to be performed. Add theseSafety Rating numbers together, then divide the sum by the Duration of Work Adjustment from Step 5.The resulting number is the Composite Safety Rating for the task. Compare this number to the FumeControl RequirementsqChart to determine the appropriatepp pcontrols for the task.If the tasks to be performed are not included in this job aid, contact the Site Health and SafetySpecialist for fume control guidance.Step 1: ProcessSafety RatingGTAW, Oxy-fuel Welding, or GMAW short-circuittransfer1SMAW (3/32" & 1/8" diameter electrodes), Oxyfuel Cutting, Oxy-fuelOxy fuel Brazing, or GMAW spray orpulse transfer2SMAW (5/32" diameter and larger electrodes),FCAW3Air Arc Cutting or Gouging with round electrodes1/4" diameter and smaller, or Plasma Arc Cuttingor Gouging4Air Arc Cutting or Gouging with flat or roundelectrodes larger than 1/4"1/4 diameter5GTAW Gas-Tungsten Arc Welding (TIG) GMAW Gas-Metal Arc Welding (MIG) SMAW Shielded Metal Arc Welding (Stick or Manual Arc Welding) FCAW Flux Core Arc Welding

Step 2: Filler Metal/Base MetalWeldingSafetyRatingThermal CuttingGTAW using steel, stainless steel, nickel,copper, or cobalt filler rods0n/aGTAW and GMAW on aluminum,ER4043 ER5554,ER4043,ER5554 or ER55561n/a/E7018, E6010, E6013, E71T-10P#1 carbon steel (A36, SA-106 Gr. B)E7018-A1, E8018-B2, E6013, E81T1-B21P#3 and P#4 alloy steel (T1a, T11, F11)E9018 B3 E91T1-B3E9018-B3,E91T1 B32P#5A alloy steel (T22(T22, P22P22, F22)E9018-B7, E9018-B9 (old E502 andE505)3P#5B alloy steel (T5, T7, T9, T91)E3xx-15, E3xx-16, E3xxT-14P#8 stainless steel (304, 316, 347)Nickel electrodes, ENiCrFe-2, ENiCrFe3, ENiCrMo-10, Eni-Cl, ENiFe-Cl5P#43 and similar nickel alloy (iconel alloys 622,625, nickel Hastelloys)EcU, ECuNi, EcuSi, ECuSn, ECuAl5Copper, Bronze, BrassECoCr-A ECoCr-BECoCr-A,5Cobalt (Stellite 6,6 Stellite21)5Chrome carbide hardfacing alloys, mill rolls, millbowls, breaker bars, breaker hammers4Manganese 'Hadfield'M'H dfi ld' steel,t l non-magnetictirailroad rails, frogs, wear pads0Aluminum (1100, 3003, 5054, 6061, 7075)Carbide and alloy steel hardfacing rods(see manufacturers' literature fordetails)AusteniticAt iti manganese electrodesl t d ((seemanufacturers' literature for details)n/a

Step 3: PaintPaint, PlatingPlating, or Other Coatings on Work pieceSafety RatingNone or coating removed prior to thermal cutting or welding0Ash deposits containing sulfur (rotten egg odor when heated)23Known or Suspect Zinc or Chromate - based paints(4 if paint layer is1/16" or thicker)Electroplated coatings (electro-galvanized, chromated, etc.) including EMTconduit and electro-galvanized Unistrut4Hot-dip galvanized5Cadmium plated (dull silver bolts, nuts, washers, all-thread)6

Step 4: Position and Local Ventilation UseSafety RatingOutdoors where worker can keep head out of fume plume most of the timeInside buildings where all of the following are true:1. Building/room volume is over 10,000 cubic feet per fume source (such asturbine and boiler buildings and large fuel handling garages)2. Worker can keep head out of fume plume most of the time3. Nearby workers are not exposed to concentrated fume plumeInside buildings where all of the following are true:1. Building/roomgvolume is less than 10,000,cubic feet pper fume source2. Fume capture and removal system is used (exhaust trunk or hood)3. Worker can keep head out of fume plume most of the time0Large confined spaces (boiler firebox, backpass, windbox, hydro spiral case,tanks over 10,000 cubic in volume (condensers, long tunnels) where all of thefollowing are true:1. Natural draft or mechanical ventilation creates perceptible air flow that is notswirling in the space2. Worker can keep head out of fume plume most of the time3 Nearby workers are not exposed to concentrated fume plume3.Small confined spaces that are difficult to ventilate (feed water heaterhemispherical heads, mud and steam drums, tanks less than 10,000 cubic feetin volume, underground vaults)Any location (includingAn(incl ding ooutdoors)tdoors) wherehere the workerorker cannot keep head ooutt offume plume most of the time3

Step 5: Duration of Work AdjustmentDivide ByLess than one (1) hour of fume-generating activity per eight (8) hours of work, and noindividual Safety Rating equals 4 or higher8Less than four (4) hours of fume-generating activity per eight (8) hours of work, andno individual Safety Rating equals 4 or higher2More than four (4) hours of fumefume-generatinggenerating activity per eight (8) hours of workAny duration if an individual Safety Rating equals 4 or higher1 (noreduction)1 (noreduction)