one instructor guide, poster and six videos ~ above hexavalent chromium exposure monitoring results, giving weld shops through objective data to advice potential hazards. Created by Washington State Labor and Industries" Safety and Health Investment job with the college of Washington. Part of a collection. Click the "collection" switch to access the other items.
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Table the Contents
Overview Viewing suggestions
THE VIDEOIntroduction: getting to know Chrome 6 Module 1: HexChEC Exposure Assessment tool Module 2: regional Exhaust Ventilation (LEV) Module 3: reliable Applications the LEV Module 4: Other manage Measures Module 5: Washington State room of job & Industries’ (L&I) Chrome 6 Regulation
RESOURCESWashington State department of job & markets (L&I) work Safety and Health management (OSHA) nationwide Institute for occupational Safety and also Health (NIOSH) various other References neighborhood Exhaust Ventilation (LEV) vendors
GLOSSARYacronyms American Welding society (AWS) terminology
Funding and support because that this project has actually been provided by the Washington State department of job & Industries’ safety & health and wellness Investment Projects.
You are watching: Welding in confined spaces or on stainless steel generates
Hexavalent chromium, or chrome 6, is a kind of chromium that have the right to be uncovered in welding fume when “hot work” is done on metals, such as stainless steel, that contain chromium. Exposure to fumes native welding, cutting, and also other hot metal occupational is a recognized hazard for welders, and chrome 6 has actually been receiving boosted attention native federal and also state agencies in charge of protecting workers’ health. Study has shown that workers exposed come chrome 6 are at an enhanced risk of emerging lung cancer, and also welders are the largest worker population potentially exposed to this well-known carcinogen.
In bespeak to minimize occupational exposure come chrome 6, in February 2006, the federal work Safety and also Health management (OSHA) implemented a standard, which significantly lowered the allow exposure limit (PEL) indigenous 50 come 5 micrograms every cubic meter (μg/m3), as an 8-hour time-weighted average (TWA). The regulation likewise outlines other demands to safeguard workers from exposure. The previous PEL was in reality 100 μg/m3 because that chromates (a type of chrome 6), which corresponds to 52 μg/m3 as chromium.
Working safely v chrome 6 is a mutual responsibility for welders, engineers, employers, and safety officers. This maintain package, Hexavalent Chromium Exposure Control: best Practices because that Welders (HexChEC), is a video-based program emerged to progressive awareness amongst Washington state welders and their employers around chrome 6, the standard, health effects of exposure, and also best practices for exposure control—with an emphasis on local exhaust ventilation.
The HexChEC training parcel is designed to assist welders, supervisors, and also safety officers in recognizing conditions that do overexposure to chrome 6 likely, so that ideal controls can be effectively used to minimize exposures. Local exhaust ventilation (LEV) and good work practices can reduce welders’ exposure come chrome 6 and also other hazardous welding fumes. Adopting these techniques will also make it much easier for employers come comply through the new chrome 6 regulation enforced by the Washington State room of job & sectors (L&I), division of work-related Safety and Health (DOSH). The HexChEC video clip is split into 6 customized modules, each 10 minute or less. Most of the modules are intended because that an audience the welders and their supervisors; those involved with just how L&I’s chrome 6 regulations use to your workplace may be many interested in Module 5.
The six HexChEC video modules are:Introduction: obtaining to recognize Chrome 6 Module 1: HexChEC Exposure Assessment tool Module 2: local Exhaust Ventilation (LEV) Module 3: reliable Applications the LEV Module 4: Other regulate Measures Module 5: L&I’s Chrome 6 Regulation
The six video modules were developed so they can be perceived either all in one sitting or one in ~ a time, together as during sequential safety briefings. Tiny preparation is required, and no extra materials are needed. Begin by reflecting a module and also refer to the questions and also talking points in this booklet to aid lead a discussion about the video. Objectives, summaries, discussion questions, and talking points are noted for each video clip module. If possible, viewers should have actually a copy the the HexChEC Exposure Assessment device for Stainless stole Welders (see within front covering of this booklet) as soon as watching Modules 1, 2, and 3. The HexChEC Exposure evaluate Tool, i m sorry is also obtainable as a poster, is only to be offered as a guideline and not to be relied upon because that compliance purposes.
Upon perfect of the maintain program, trainees will be able to recognize and successfully prioritize health hazards connected with welding top top chromium-containing alloys and to use the suitable workplace controls, such as effective use of local exhaust ventilation (LEV). Viewing all the video modules does not necessarily fulfill the training demands of the chrome 6 regulation. The focus of the HexChEC video is effective use of LEV when L&I requires specific training on just how employers will comply with the regulation. L&I has emerged a PowerPoint cultivate kit top top chrome 6; this may be found at www.lni.wa.gov/Safety/TrainTools/Trainer/Kits/HexaChrom/ and used for compliance-related training.
Introduction - gaining to recognize Chrome 6
After watching the development video, viewers need to be may be to:define what chrome 6 is and why the is connected to warm work ~ above stainless steel. perform three work sources of chrome 6. list 3 health impacts related to chrome 6 exposures.
Smoke and fumes, component of any kind of welding job, have the right to pose real wellness hazards. Hexavalent chromium, or chrome 6, is a microscopic metallic particle discovered in stainless stole welding fume the is created when warm work, such together welding, is excellent on stainless steel. The high warmth of the arc oxidizes the chromium in the steel, and chrome 6 is exit in the fumes. Other job-related exposures come chrome 6 include chromate paints, anti-corrosion sprays or dips, and wood preservatives.
Breathing chrome 6 is harmful to human health: it can cause holes in the nasal septum, chronic bronchitis, asthma, and dermatitis. Chrome 6 is likewise a carcinogen. Some studies have actually shown higher rates that lung cancer amongst welders, and also other research studies have displayed excess respiratory tract cancers (from 2- to more than 50-fold) in chromium manufacturing workers. To much better protect workers from this hazardous substance, commonwealth OSHA and also Washington State L&I regulate exposure levels to chrome 6. The chrome 6 permissible exposure limit (PEL) is 5 micrograms per cubic meter of waiting (5 μg/m3). Fortunately, working problems can be retained safer and also healthier for welders by using design controls such as regional exhaust ventilation (LEV).
Discussion Questions and Talking Points
What is chrome 6?Chrome 6 (hexavalent chromium or hex chrome) is:a microscope metallic particle formed when hot work is excellent on stainless steel. a carcinogen; long-term exposure come chrome 6 have the right to be hazardous to human health and increase the hazard of arising lung cancer.
How are civilization exposed come chrome 6 in the workplace?Occupational exposures to chrome 6 may occur during:welding or hot cutting ~ above stainless steel, other steels with high chromium content, or metals coated with chromate paints. spray application or produce of chromate pigments and also paints. work-related with anti-corrosion coatings (sprays, dips, chromic-acid plating tanks). work-related with hardwood preservatives.
What are the health impacts of irreversible exposure to chrome 6? Harmful health and wellness effects connected with chrome 6 include:skin irritation, dermatitis, ulceration. asthma, bronchitis, respiratory irritation. sleep irritation, nosebleeds, feet in the sleep septum, sleep cancer. lung cancer.
How space welders defended from overexposure come chrome 6? Chrome 6 exposure is regulated by OSHA and also L&I:federal OSHA to adjust a PEL to manage exposure come chrome 6 in the work place. The PEL because that chrome 6 is 5 μg/m3, averaged over an 8-hour workday. In Washington state, L&I’s department of job-related Safety and Health (DOSH) has promulgated regulations to defend welders, including those exposed come chrome 6. Their chrome 6 regulation is the same to the federal OSHA standard. efficient use that LEV deserve to keep welders for sure and aid workplaces comply with regulatory requirements.
MODULE 1 HexChEC Exposure evaluate Tool
After the town hall Module 1, viewers have to be able to:surname the two work problems that most influence a welder’s exposure to chrome 6 and other welding fumes. categorize welding and also cutting processes based on risk the chrome 6 overexposures, from greatest to lowest risk. categorize work-related spaces based upon risk that chrome 6 overexposures, from greatest to shortest risk. define why product Safety Data Sheets (MSDS) are important to above in assessing risk of chrome 6 overexposure. use the HexChEC Exposure Assessment device to identify the recommended controls to usage for a certain hot-work procedure and work space.
The risk of metal fume fever shortly after welding ~ above galvanized stole or Inconel® is fine known; however, it’s uncommon to endure these acute health results after welding top top stainless steel. Stainless steel has actually a reputation amongst welders for being a “clean” steel that is no as hazardous to work on as various other materials, such together galvanized metals (containing zinc), Inconel® (containing nickel and chromium), or aluminum. In fact, consistent overexposure come chrome 6 from warm work top top stainless steel has actually serious irreversible health effects such as sleep ulcers, bronchitis, asthma, and also even lung cancer, which is why part welding instructors contact chrome 6 “the covert hazard.” It’s important that workplaces are equipped with proper ventilation to save welders safe and to save their exposures to chrome 6 and also other welding fumes listed below the permit exposure border (PEL).
Welding is a facility process and there are numerous variables concerned fume generation and also exposure. The HexChEC Exposure evaluate Tool provides it straightforward for welders to determine their personal risk the overexposure come chrome 6 throughout a particular job by concentrating on the 2 work conditions that add most to exposures: 1) the hot-work procedure they room performing, and 2) the work space or ar in i beg your pardon they are working. Recognizing that chrome 6 exposures rely on process and work room will assist welders understand exactly how to select the most suitable controls. The data presented below is based on chrome 6 exposure monitoring performed by the university of Washington ar Research and also Consultation group over the previous two year in a variety of weld shops, shipyards, foundries, and fabrication facilities. Every data are personal 8-hour time-weighted median (TWA) results.
Carbon and also plasma arc cutting result in the highest possible chrome 6 exposures followed by stick and then flux main point welding. MIG welding produces a variety of chrome 6 exposures that are regularly right about the PEL. Submerged arc and TIG welding produce low exposures.
Welding and also cutting procedures ranked from greatest to lowest danger of overexposure come chrome 6:CAC/PAC (Carbon arc cutting/Plasma arc cutting) SMAW (Stick)FCAW (Flux core) GMAW (MIG) GTAW (TIG) experienced (Sub Arc)
|TWA exposures through process|
|Process||Average (μg/m3)||% exceeding PEL|
|FCAW (Flux core)||13.3||59|
|SAW (Sub Arc)||0.08||0|
|* greater task-duration concentrations, however not frequently performed full-shift|
Exposure come chrome 6 additionally depends top top the airflow and ventilation easily accessible in the work-related space. Hazard of overexposure increases as welders relocate from outdoors to an open up shop space, to a minimal or enclosed space, come a limit space.
Work spaces ranked from highest possible to lowest danger of overexposure come chrome 6:
|Confined Spacenot draft for human occupancy, with limited entry or exit; for example, tanks, vats, pipes, ovens, vaults|
|Restricted space welding booths or cells, locations with displays or curtains, a “hooch” or time set-up, likewise includes the maritime definition of enclosed space|
|Open Space high ceilings (16 ft), ceilings or wall surface fans present, totally free airflow with bay doors, available room per welder better than 10,000 ft3|
|Outdoorsoutside in the open air v no obstructions|
|TWA exposures by job-related space|
|Work space||Average (μg/m3)||% exceeding PEL|
Putting the Together
The HexChEC Exposure evaluate Tool, i beg your pardon is based on monitoring data collected by UW industrial hygienists, is a overview that enables welders come quickly pick what level of defense they need for your jobs. A copy that the device is consisted of inside the sheathe of this booklet and also is also available separately as a poster. By identify the particular procedure and the work an are along the spare part of the table, welders can quickly determine if:herbal or general ventilation is adequate to regulate fumes, or LEV or respiratory tract protection might be needed, or LEV and respiratory defense are required.
The Exposure Assessment tool assumes that the welders who usage it will be working on stainless steel. Stainless steel is an alloy which frequently contains 10 come 30% chromium. This doesn’t average that functioning on an alloy with a low chromium contents won’t result in any kind of exposure come chrome 6. In a limit space, chrome 6 exposures have actually been measured throughout hot job-related on metals containing much less than 3% chromium.
It’s important to keep in mind the the filler steel contributes as much as 95% that the full welding fume, when the base metal only contributes around 5% the the fume. Welders and also supervisors should constantly consult material Safety Data Sheets (MSDS) come accurately recognize the chromium contents of both the filler and base metals they are using. The more chromium there is in the filler and also base metals, the more chrome 6 is in the welding fume.
Discussion Questions and also Talking Points
Why is chrome 6 dubbed “a hidden hazard?” A usual misperception is the stainless steel is a safer steel to occupational on than alloys with zinc, nickel, manganese, or aluminum. Till recently, the risks of chrome 6 weren’t as well known together other metal fumes. Chrome 6 welding fume doesn’t reason acute health and wellness effects, together as steel fume fever. The health impacts of chrome 6 space chronic or long-term—health results may not display up till after year of exposure.
What are two work problems that are good predictors the chrome 6 or other steel fume exposure? The two variables most closely linked with chrome 6 exposures are the welding procedure and work space.
Discuss typical processes offered in the shop. Give different scenarios and ask welders to usage the Exposure Assessment tool to evaluate danger of exposure for various work processes and in different work spaces.
Why are product Safety Data Sheets (MSDS) crucial to consult as soon as assessing chrome 6 exposure? material Safety Data Sheets perform the chromium content of base and also filler metals: no all stainless steel products are the same. Products with greater chromium contents will normally generate fume with greater concentrations that chrome 6. Filler metals add up to 95% of total welding fume—the chromium contents of the filler metal has actually a significant effect ~ above the chrome 6 concentration in the welding fumes. review MSDS for miscellaneous stainless steel and other metals and filler products used in the shop to compare the chromium contents of each. Take into consideration using materials with lower chromium contents to alleviate potential exposures.
MODULE 2 neighborhood Exhaust Ventilation (LEV)
after ~ watching Module 2, viewers need to be maybe to:explain the differences in between natural, general, and also local exhaust ventilation. surname the four straightforward parts of one LEV system. recognize the distance and the position the LEV hood must be indigenous the weld. identify the correct catch velocity because that an LEV system and explain why this capture velocity is recommended.
efficient ventilation is one of the finest ways to reduce chrome 6 exposures. The form of ventilation compelled depends on eco-friendly conditions, the work procedure used, and also the occupational space.
|Natural Ventilation||General Ventilation||Local Exhaust Ventilation|
Types the Ventilation
Natural ventilation occurs when air enters through open windows or doors.
General ventilation offers a fan or an HVAC device to move big quantities of air to dilute contaminants.
Local exhaust ventilation (LEV) records contaminants at your source, prior to they reach a worker’s breathing zone.
Natural and general ventilation may not be adequate to catch fumes when performing warm work top top stainless steel. LEV is one of the ideal ways to alleviate exposure to airborne contaminants like chrome 6. One LEV system doesn’t need to be fancy, sophisticated, or cost a lot. Plenty of welding shops and shipyards placed together their very own systems v a an easy fan or blower, and some ducting. Some solution may additionally have an wait cleaning machine like a high-efficiency particulate waiting (HEPA) filter.
Here some points to consider when choosing an LEV system:have the right to the hood and duct acquire close enough to the source of the welding fume without acquiring in the method of the work? Is the LEV portable so it deserve to reach the allude of the weld once working in a solved location? Is versatile or rigid ducting needed? will the fan and also ductwork—which role together—adequately capture and move the fumes far from the welder and nearby workers? whereby will caught air be exhausted? Is an waiting cleaner like a HEPA filter needed? How frequently should HEPA filter be cleaned or replaced?
To acquire this 100 fpm capture velocity, the hood the the LEV must be positioned in ~ 1.5 hood or duct (if no hood is available) diameters native the arc. This guideline is based upon experimental velocity contours because that round and rectangular hoods (Industrial Ventilation: A hand-operated of encourage Practice, ACGIH, 2007), and assumes a minimum volume of air flow measured in cubic feet per minute (cfm). Most commercially available LEV systems offered for welding fume extraction are rated to administer anywhere from 600 to 2000 cfm airflow. These, together with the many commonly listed ducts and hoods, should provide adequate catch velocities when positioned in ~ 1.5 hood or duct diameters away from the arc. Store in mind that this street is a general ascendancy of thumb and capture velocities need to be measured at the arc come ensure that around 100 fpm is maintained. Measurements deserve to be taken utilizing a maker called a thermal anemometer.
Regulatory agencies are an ext concerned through whether the PEL has actually been gone beyond than whether the duct is positioned in a certain location; following the 1.5-diameter tip should aid weld shops comply with the PEL. Contact an industrial hygienist to help evaluate exposure and/or ventilation.
When working on a huge part, preserving this distance will require that the hood be typically repositioned. The hood have to be positioned at an angle— one that’s not directly above the welder’s head!—that adequately records the welding fumes and also draws them far from the breathing zone. Devoted exhaust hoods for each work an are are recommended; too plenty of ducts pulling turn off the exact same fan will alleviate the air volume being relocated at each location. Again, call an industrial hygienist (for example, a DOSH consultant or a consultant native the college of Washington ar Research and Consultation Group) to evaluate ventilation systems and also offer recommendations.
Discussion Questions and Talking Points
What space the differences in between natural, general, and local exhaust ventilation?
Ventilation is supplied to control contaminants—such as chrome 6—in the occupational environment:Natural and also general ventilation dilute the concentration that chrome 6 by giving fresh air, yet they don’t necessarily eliminate contaminants from the workers’ breath zone. natural ventilation takes benefit of naturally developing airflow, such as the wind outside, or cross breezes from open up bay doors. general ventilation contains the usage of cooling pan or HVAC systems. Natural and general ventilation may be ideal for a job, however only if: the work an are has high ceilings (16 feet), and also the room per welder exceeds 10,000 cubic feet, and there room no barriers or curtains come obstruct airflow. Natural and also general ventilation space never adequate in border spaces. local exhaust ventilation (LEV) is an engineering control that captures, removes, and exhausts the contaminated air, frequently through a filter. LEV, like general ventilation, is also mechanical yet it moves a smaller sized amount of air much more efficiently and should not disrupt the shielding gas. LEV is the preferred an approach of ventilation.
What are the straightforward parts of an LEV system?LEV equipment have 4 (4) an easy parts:The hood or enclosure to capture the contaminant, including welding fumes, in ~ the source. Ductwork, which transports the welding fume from the hood come the fan. A pan to pull the air with the hood, duct work, and also air clean device. one air cleaning device, such as a filter, to eliminate the contaminant indigenous the air for this reason it’s not blown back into the shop or right into a room where others may be working.
What is the suitable capture velocity because that an LEV system?Most LEV equipment for welding are designed to move a volume of air the will carry out a catch velocity of 100 feet every minute at the arc. To keep this optimal fume capture:the hood should be 1.5 hood or duct diameters native the arc. the hood have to be above the arc and also at one angle, far from the breathing zone. Keep in mind the welding fumes naturally rise.
MODULE 3Effective Applications of regional Exhaust Ventilation (LEV)
~ watching Module 3, viewers must be able to:explain the distinctions in potential exposures when welding outside, in a hooch, in a shop, and in a limit space. define what have to happen prior to a welder does hot work in a limit space. describe why the position of the LEV hood is crucial in reducing chrome 6 exposures.
Module 3 uses video clip exposure security (VEM) in three various hot work scenarios to to mark the effective use of LEV. VEM is a an approach in which full dust (welding fume) is measured every 2nd and visually represented by a red bar whose height transforms in actual time on a computer system screen, together the worker’s exposure changes. In this video, we usage a real-time aerosol screen to measure full dust or welding fume outside the welder’s helmet. VEM permits the viewer to watch how complete fume exposure alters with the process, work-related space, and also LEV that the welder uses. VEM visually demonstrates reliable LEV use, which contains keeping the hood within 1.5 hood or duct diameters from the arc and positioning it at an edge that will certainly pull the fumes away from the welder’s breathing zone.
VEM script 1
Process: stick welding work Spaces: Outdoors and also in a minimal space (a hooch, or tent approximately outdoor welding)
rod welding is a smoky process. Also though welders regularly think the the fume will certainly be puffy away when outdoors, overexposures may still occur. Wind is organic ventilation the can’t be controlled. Gentle cross breezes have the right to push fumes into the welder’s breath zone, increasing exposures.
Setting up a “hooch” may boost airborne overexposures. Although a hooch protects the welder and weld from the weather, it considerably reduces airflow and can rotate an outdoor work an are into a restricted work space. Without LEV, welding fumes quickly develop up within a hooch and also overexposures room likely. Through LEV, welding fumes are captured and removed from the welder’s breath zone. If over there is no filter on the LEV system, make certain that the LEV is no exhausting back into the “hooch” or right into an surrounding welder’s job-related area.
VEM scenario 2
Processes: Flux core and MIG weldingWork Space: In one open space (a fabrication shop)
Flux main point arc welding is additionally a smoky procedure that usually results in overexposures. Even flux core welding in an open shop calls for LEV. In this scenario, we show LEV positioned too much away and directly over the welder’s head, both result in greater exposures than when the LEV is positioned above, however at an angle to the side of the welder, around 1.5 hood diameters from the arc.
Estimating exposures because that MIG welding is less straightforward and also depends a many on the natural and general ventilation available in a given work space, but LEV is tho recommended. When exposures during MIG welding in the shop room not as high as during flux main point welding, appropriately positioned LEV results in also lower exposures. The goal is always to alleviate chrome 6 exposures as much as possible.
VEM scenario 3
Processes: rod welding and also carbon arc cutting job-related Space: In a confined an are (the ballast that a dried dock)
Stick welding is a smoky process. The is often used to weld in confined spaces because it is therefore portable. Carbon arc cutting has actually the highest fume generation of all the hot-work processes disputed in this video. Both the these work pose a high risk of overexposure. In a confined space, these processes will certainly produce high airborne chrome 6 concentrations.
any time hot work is excellent in limit spaces, mechanically ventilation have to be provided. If LEV cannot provide sufficient exposure control, supplied-air respirators might be required. Prior to entry, confined spaces should be tested, inspected, and also determined for sure by a certified maritime chemist, industrial hygienist, or various other qualified person. A document of these tests and a permit need to be kept.
The LEV system used in ~ the dried dock presented in the video has six-inch versatile ducting and also is fine suited for confined space work. Once positioning LEV in a minimal or limit space, keep in psychic that any bends and kinks in the hose affect the effectiveness of the LEV system and also its ability to capture air. If sparks are developed as the job-related is done, be cautious that the sparks don’t record the ductwork on fire. V carbon arc cutting, the high temperatures and also travel the the sparks may produce a fire peril if the duct job-related is positioned downwind.
Discussion Questions and also Talking Points
How go potential exposure come welding fume change with various work spaces?As air flow or ventilation in a work room is reduced, the hazard of overexposure to chrome 6 increases:The hazard of chrome 6 overexposure increases as the welder moves from one outdoor space to spaces where natural ventilation and general ventilation space limited, such together spaces that are open (in a shop), restricted (in a hooch or small welding booth or cell), or border (in a tank). natural ventilation can’t be controlled—a breeze might not be enough to eliminate the fumes, or that may also blow the fumes into the welder’s breathing zone. Also in the outdoors, LEV might be needed to keep exposures low.
What steps must it is in taken prior to a welder deserve to enter and also work in a confined space?Stainless steel welding in border spaces have the right to produce very high airborne chrome 6 concentrations. In fact, any kind of hot occupational in a confined room can result in high welding fume exposures. Before a welder can enter and also work in a limit space, the adhering to are required:An commercial hygienist or safety professional, a marine chemist(onboard a vessel), or other qualified human being must inspect, test, and certifythe an are as for sure for entry. A permit need to be post at the point of entry. Mechanical ventilation should be in place.If LEV cannot carry out sufficient defense to preserve airborne concentrations below the PEL, respiratory defense is required. Depending on exposures, positive pressure respirators, such together a powered air-purifying respirator (PAPR) or supplied-air respirator (SAR), may be needed.What is the correct place of LEV and also why is keeping this position important?It is not sufficient to just have actually an LEV system. LEV have to be used efficiently or it will not catch the fumes and pull them far from the welder’s breath zone. The hood that the LEV have to be placed around 1.5 hood or duct diameters indigenous the arc, the resource of the fumes. Use duct diameters if the LEV doesn’t have a hood attached come the ducting. If the LEV has actually a rectangle-shaped hood, use the longest side of the hood to judge the street for exactly placement. The hood should be positioned above and to one next of the arc, and also at an angle (as a guide, imagine the hood in ~ a 45-degree edge to the arc). stop kinks or bends in the LEV ductwork, as these will rise friction losses and decrease the airflow. MODULE 4 Other manage Measures
after watching Module 4, viewers have to be able to:identify at least three different methods for reducing exposure to chrome 6 (in enhancement to effective use the LEV). describe why substituting welding materials might be a way to mitigate chrome 6 exposures. describe why substituting a different welding procedure might it is in a means to reduce chrome 6 exposures.
Measures that reduce chrome 6 exposures (besides an LEV system) are elimination, substitution, engineering, bureaucratic controls, and personal protective equipment. Commercial hygienists rank these controls indigenous most reliable (elimination) come least reliable (respiratory protection) and call this order the “hierarchy that controls.” due to the fact that welders might not have actually input into just how the task is done, Module 4 might be an ext relevant come welding engineers and supervisors.
Hierarchy of ControlsEliminate the hazardExposure to chrome 6 can be removed if the component can be built in a way that doesn’t involve hot work; because that example, using rivets, screws, or bolts to attach parts. Substitute the basic or filler metals with metals that have lower percent chromium products with higher chromium contents release an ext chrome 6 throughout hot work. If the occupational site provides high-chrome fillers, it’s precious checking to see whether materials with lower chromium content have the right to be substituted. Plenty of weld shops are properly using 9% chromium materials where possible; this seems to fulfill quality specifications in many cases while generating welding fumes with lower levels the chrome 6. usage a cleaner welding processIf possible, opt because that a welding procedure that generates less fumes. For example, plasma cutting generates much much less fume than carbon arc cutting; MIG generates less chrome 6 보다 flux core; pulsed MIG generates much less chrome 6 than quick circuit or spray transport MIG; and also TIG generates much less chrome 6 보다 MIG. Researches have shown that making use of a cleaner welding procedure can minimize chrome 6 exposures by 60 to 90%. Reduce the amperage and voltageWelding parameters such together amperage and voltage often have upper and lower varieties that will job-related to acquire the job done. To decrease amperage and also voltage may reduce chrome 6 fumes. Use a filler wire or rod through a smaller sized diameterFiller product contributes an ext fume 보다 base metal. Using a cable or rod with a smaller sized diameter have the right to reduce exposure to chrome 6. The L&I welding regulation requires additional general ventilation as soon as using larger diameter welding rods or wire. Change the shielding gasCO2 shielding gas rises the likelihood the overexposures due to the fact that pure CO2 creates good conditions for oxidizing chromium right into chrome 6. Particular gas blends have been shown to alleviate the generation the chrome 6. An argon/CO2 blend can provide better shielding and also creates less fumes. Making use of nitrogen gas rather of compressed air for plasma cutters can reduce exposures to chrome 6 and other metal fumes. inquiry flux materials that mitigate chrome 6The contents of the flux discovered in stick and flux main point arc welding stabilize chrome 6 in the air, permitting it to “hang around” longer. Research study is being performed to evaluate ways to change flux materials to alleviate the lot of chrome 6 the is generated. change body position human body position can influence welders’ exposure come chrome 6 and other welding fumes. Transforming position deserve to be an easy modification come make. Any welding place that permits the fume to circulation through the breathing zone can substantially increase exposures. Even little adjustments can make a large impact, for this reason welders must be reminded to save their heads the end of the smoke. Return it counts on the occupational environment and also airflow conditions, flat position welding may result in greater fume exposure and overhead welding may lead to lower fume exposure. Use respiratory tract protectionIf making use of LEV or other controls defined previously is inadequate to store chrome 6 exposures listed below the PEL, welders are required to stay respirators. Some instances require both LEV and respiratory protection. If employees are listed with respirators, top the L&I regulation for respiratory defense (WAC 296-842). Half-face respirators with HEPA or P-100 filters defend welders from exposures up to 10 times the PEL; if exposures exceed the PEL by an ext than 10 times, powered air-purifying respirator (PAPR) helmets or provided air respirators are required. A PAPR has a protection element of 25 come 1000, relying on helmet style and fit.
Discussion Questions and Talking points
What controls exist to mitigate chrome 6 exposures when warm work is done on stainless steel?
Elimination or substitutionreadjust the base or filler steels for products with reduced percent chromium. Opt because that a hot-work procedure that generates the the very least fumes.
Engineering controlsusage mechanical ventilation such as LEV. minimize the amperage and voltage. Usage a cable or rod through a smaller diameter. switch from a pure CO2 shielding gas to an argon/CO2 blend.
Administrative controls/Personal protective tools (PPE)repeat welders to store their heads out of the smoke. carry out respirators, if needed.
MODULE 5 L&I’s Chrome 6 Regulation
After city hall Module 5, viewers need to be maybe to:explain the significant components that the chrome 6 regulations/standard. perform L&I’s permissible exposure border (PEL) and action level (AL) for chrome 6. recognize the actions forced if air sampling results reveal the employees are: below the AL above the AL but below the PEL over the PEL for a task that is done much less than 30 days in a year over the PEL because that a project that is done an ext than 30 days in a year.
In 2006, DOSH passed new chrome 6 regulations. The regulations are detailed and also employers will must regularly consult them. Refer to the L&I resources listed at the finish of the guide for more complete details.
The HexChEC maintain package focuses on neighborhood exhaust ventilation and also other control methods the employers might use to continue to be compliant. An overview of the sections of the DOSH regulation is presented below:
Know the allow exposure border (PEL) and the action level (AL)The PEL borders workers’ exposures come an airborne concentration less than 5 micrograms that chrome 6 every cubic meter of air, averaged over one eight-hour occupational shift. The AL is set at one-half the PEL, or 2.5 micrograms the chrome 6 every cubic meter that air, averaged over an eight-hour occupational shift. With effective LEV, employers may be able to ensure their welders are not exposed come chrome 6 over the AL. If exposures exceed these limits, the following requirements may apply in the workplace.
Monitor the chrome 6 exposure the workers who do warm work on stainless steel Personal waiting samples should be built up in accordance with OSHA ID-215 (version 2). Inspect with an industrial hygienist for an ext information top top the approved sampling an approach and AIHA-accredited laboratories that deserve to perform the analysis. Samples have to represent all the different hot-work work that space done in the shop. Monitoring will have to be repeated if there are alters in process or manufacturing that could change chrome 6 exposures. Monitoring results should be mutual with welders even if much less than the PEL. Welders who space exposed above the PEL must be notified.
The regulation requires program monitoring of representative employee performing on regular basis scheduled stainless stole hot-work processes. In many cases, these processes don’t occur on a constant basis so the usage of objective airmonitoring data is also permitted. The data that the UW ar Research and also Consultation team (FRCG) has been collecting are an instance of target data, as characterized by the regulation. In order to usage these data, work problems must be really similar. For an ext information top top the use of target data, please contact L&I or the UW FRCG, or describe the regulation.
Keep records related come the regulation Managers should keep all documents of wait sampling and also medical surveillance results for at least 30 years. The is good policy come share the results with employees, even if the outcomes are below the PEL. Clinical reports have to be retained confidential.
Train workers on the chrome 6 regulation Having workers check out this video is not sufficient training to it is in in compliance with the standard. L&I has a PowerPoint maintain program obtainable on your website that have the right to be adjusted and supplied to fulfill these requirements. Check the sources section in this manual for the ar of this materials.
Establish housekeeping procedures and also regulated locations These two sections of the standard apply only to general industry; they carry out not apply to building or maritime work. Nevertheless of airborne exposures, actions need to be take away to keep surfaces as free of chrome 6 contamination as possible. Argued cleaning methods include vacuuming surfaces through a HEPA vacuum or utilizing a wet rag come wipe under surfaces. Waste, scrap, debris, or any type of other materials contaminated through chrome 6, consisting of LEV device filters, should be inserted in sealed, impermeable bags or other closed containers because that disposal. Examine with local hazardous garbage regulators to see exactly how to dispose the chromium-contaminated waste.
Where airborne exposures are most likely to exceed the PEL, the employer must establish a regulation area the is separated indigenous the remainder of the shop and to alert and also require those entering the area come take proper precautions to safeguard themselves indigenous exposure.
Provide suitable protective clothing and hygiene areasWhen a chrome 6 peril is present, job are compelled to administer protective work-related clothing and also equipment at no fee to employees. Added protective clothing, such together Tyvek®, might not be essential for welders functioning on usual stainless stole projects due to the fact that they are already protected native skin hazards such as UV radiation and also burns.
Where protective garments is provided, washing infrastructure must be obtainable so that employees can wash their hands and faces prior to eating and drinking. Different eating and drinking locations must be kept totally free of chrome 6 contamination. Industrial hygienists deserve to collect surface ar wipe samples in hygiene locations to advice compliance with these requirements.
Provide respiratory protection, if needed If design controls and LEV room not sufficient to save exposures listed below the PEL, respirators are needed. Respirators are likewise necessary when LEV is not obtainable or when it is being installed and also checked. Some situations—such as hot work in a border space—require respirator use. Otherwise, respirators are much less reliable than engineering controls prefer LEV, can be much more expensive come maintain and use, and also may create problems, such as placed stress top top the health of employee who might not be fit come wear them.
The layout of respirator forced depends ~ above chrome 6 concentrations. If exposures space up to 10 times the PEL, half-face respirators with P-100 cartridges must be worn, however if exposures exceed 10 times the PEL, respiratory defense with a better protection element must be used. This contains a powered air-purifying welders’ helmet, which has a protection variable of 25, meaning that it can be worn in atmospheres up to 125 μg/m3. Welders respond favorably to this respirators due to the fact that they administer the very same eye defense as welding helmets, extr respiratory protection, and cooling. Confined room hot work often requires the use of offered air respiratory tract protection. Please describe L&I’s respirator typical (WAC 296- 842) for an ext information.
Provide medical surveillanceWhere full-shift exposures room at or above the activity level (2.5 μg/m3) for more than 30 job a year, employers must provide medical monitoring to those employees at no charge. A licensed health treatment professional (for example, an work-related physician or occupational health nurse) have to perform an examination with emphasis on chrome 6 exposures and also the respiratory tract.
Discussion Questions and also Talking Points
What need to employers carry out if air sampling expose exposures are above the AL but below the PEL? In enhancement to complying with the straightforward requirements, job must:repeat waiting sampling every six months till levels are listed below the activity level, carry out medical surveillance v an occupational medication doctor or other appropriate health care provider, and administer training ~ above the demands of the regulation.
What do employers should do if air sampling expose exposures are above the PEL because that a job that is done much less than 30 days in a year? In addition to following the straightforward regulations, employers must:repeat air sampling every three months till levels are listed below the AL, re-publishing these outcomes with employees, provide respiratory protection, and establish regulated areas in places where employee exposures are expected come be greater than the PEL. It is typically recommended to enable stainless steel hot work in just one area the the shop. Note: job rotation is no a permitted method to reduce exposures.
What perform employers should do if waiting sampling reveals the exposures are above the PEL for a job that is performed more than 30 job in a year?In addition to adhering to the straightforward regulations, labor must:install and use feasible design controls, such together LEV, or readjust work methods to minimize exposures below the PEL.
If this controls and also work practices do not mitigate exposures listed below the PEL, climate respirators space required.
Washington State room of job & markets (L&I)
Mailing: PO box 44810, Olympia, WA, 98504-4810 State mail: 44810Location: 7273 Linderson means SW, Tumwater, WA, 98501-5414 Tel: 1-800-423-7233 (1-800-4BE-SAFE)Web: www.lni.wa.gov
L&I Consultation workplaces
Region 1 425-290-1431 Counties: san Juan Island, Skagit, Snohomish, Whatcom
region 2 206-515-2837 County: King
Region 3 253-596-3917 Counties: Clallam, Jefferson, Kitsap, Pierce
Region 4 360-902-5472Counties: Clark, Cowlitz, Grays Harbor, Klickitat, Lewis, Mason, Pacific, Skamania, Thurston, Wahkiakum
Region 5 509-886-6570 Counties: Adams (West County), Benton, Chelan, Columbia, Douglas, Franklin, Grant, Kittitas, Okanogan, Walla Walla, Yakima
Region 6 509-324-2543 Counties: Adams (East County), Asotin, Ferry, Garfield, Lincoln, Pend Orielle, Spokane, Stevens, Whitman
L&I Washington administrative Code (WAC) regulation
Confined Spaces—WAC 296-809http://apps.leg.wa.gov/wac/default.aspx?cite=296-809-099
Hexavalent Chromium training Kitwww.lni.wa.gov/Safety/TrainTools/Trainer/Kits/HexaChrom/
Hexavalent Chromium— WAC 296-62, component 1-2 http://www.lni.wa.gov/safety/rules/chapter/62/WAC296-62.PDFA copy is also easily accessible from L&I’s central office.
Respirators—WAC 296-842 http://www.lni.wa.gov/safety/rules/chapter/842/WAC296-842.PDF
Occupational Safety and Health management (OSHA)
Health results of Hexavalent Chromium. OSHA truth Sheet (2006)www.osha.gov/OshDoc/data_General_Facts/hexavalent_chromium.pdf
Hexavalent Chromium, Safety and also Health Topicswww.osha.gov/SLTC/hexavalentchromium/index.html
Hexavalent Chromium, Sampling and Analytical Method— technique ID-215 (version 2)www.osha.gov/dts/sltc/methods/inorganic/id215_v2/id215_v2.html
Hexavalent Chromium, Wipe Sampling Method—Method W4001 www.osha.gov/dts/sltc/methods/validated/t-w4001-fv-02-0104-m/t-w4001- fv-02-0104-m.html
job-related Exposure to Hexavalent Chromium commonwealth Register 71:10099-10385 www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=FEDERAL_ REGISTER&p_id=18599
Small entity Compliance guide for the Hexavalent Chromium standards OSHA publication 3320 (2006) www.osha.gov/Publications/OSHA_small_entity_comp.pdf
National academy for job-related Safety and also Health (NIOSH)
Criteria record Update: job-related Exposure to Hexavalent Chromium www.cdc.gov/niosh/docket/nioshdocket0144.html
Hexavalent Chromium, NIOSH Safety and Health object www.cdc.gov/niosh/topics/hexchrom/
ar Guide for momentary Ventilation of confined Spaces through Michael K. Harris, et al. Published by American commercial Hygiene Association, 1996.
industrial Ventilation: A hands-on of recommended PracticePublished through American Conference of Governmental commercial Hygienists, Inc., 2007.
Safety in Welding, Cutting, and Allied ProcessesAn American national Standard, ANSI Z49.1:2005 American Welding society www.aws.org/technical/facts/Z49.1-2005-all.pdf
Welding Health and also Safety: A ar Guide for OEHS specialists by Michael K. Harris. Released by American industrial Hygiene Association, 2002.
Welding Fume Controls
Dennis JH, French MJ, Hewitt PJ, Mortazavi SB, Redding CA. Manage of exposure come hexavalent chromium and also ozone in gas metal arc welding the stainless steels by use of a an additional shield gas. Ann Occup Hyg 46(1):43- 8, 2002.
Dennis JH, Mortazavi SB, French MJ, Hewitt PJ, Redding CR. The impacts of welding parameters top top ultra-violet light emissions, ozone and CrVI development in MIG welding. Ann Occup Hyg 41(1):95-104, 1997.
Hovde CA, Raynor PC. Results of voltage and also wire feed rate on weld fume characteristics. J Occup Environ Hyg 4:903–912, 2007.
Keane M, rock S, Chen BT, Slaven J, Schwegler-Berry D, Antonini JM. Hexavalent chromium contents in stainless stole welding fumes is dependence on the welding process and shield gas type. J of Environ Monit 11:418–424, 2009.
Yoon CS, Paik NW, Kim JH. Fume generation and content of full chromium and also hexavalent chromium in flux-cored arc welding. Ann Occup Hyg 47: 671–680, 2003.
Video Exposure Monitoring
evaluating Workplace Exposure Using straight Reading tools and video Exposure security Techniques. United state Department that Health and also Human solutions (DHHS), nationwide Institute for work Safety and Health (NIOSH), publication No. 92-104, 1992.
Rosén G, Andersson IM, Walsh PT, Clark RD, Säämänen A, Heinonen K, Riipinen H, Pääkkönen R. A testimonial of video exposure security as an occupational hygiene tool. Ann Occup Hyg 49(3):201–17, 2005.
Local Exhaust Ventilation (LEV) Vendors
Air cleaning Technologyhttp://www.aircleaningtechnology.com/orig/applications/welding.htm
Air Quality design AQE 2000 www.air-quality-eng.com/aqe_2000.php
Air Systems worldwide Confined an are Ventilation Equipmentwww.airsystems.com
Airflow systems www.airflowsystems.com/products/portable-dust-collectors.php
Clean waiting Americahttp://clean-air.com/clean-air-america-products
Donaldson Torit Easy-Trunk and Porta-Trunkhttp://www2.donaldson.com/torit/en-us/pages/default.aspx?
ESTA SRF K-10www.esta-senden.de
Lincoln Mobiflex 200-M and also 400-MSwww.lincolnelectric.com
Miller “FiltAir” Portable Fume Extractorswww.millerwelds.com/products/fumeextraction/filtair/
Nederman, Inc. Portable Fume Extractors www.nederman.com
United Air specialists Portable ESP Mist Collector (AKA “Smog-Hog,” “Porta-Hog,” or “Dust Hog”)www.uasinc.com/PCN.aspx
Action level (AL)The action level (AL) is set at one-half the the PEL, or 2.5 micrograms per cubic meter (2.5 μg/m3) of air calculated together an 8-hour time-weighted mean for chrome 6. Maintaining exposures listed below the AL offers increased assurance that employees will not be exposed to chrome 6 in ~ levels above the PEL because of exposure sport in the workplace. Once exposures room at this concentration or above it, job are forced to begin a range of action to safeguard their workers.
AcuteAn acute exposure is one of quick duration, normally to relatively high concentrations or quantities of material; may an outcome in acute wellness effects, which are adverse impacts on a human, through symptoms emerging rapidly (within minutes to hours).
Breathing zoneThe room around and in former of an employee’s nose and mouth, creating a hemisphere v a 6- come 9-inch radius.
Capture velocityAir speed crucial to overcome opposing air currents and draw a contaminant right into a hood. Reliable LEV equipment should preserve a catch velocity that 100 feet every minute in ~ the arc.
CarcinogenA cancer-causing problem or agent.
ChronicA chronic exposure is consistent or intermittent, extending over a long time period, and usually linked with reduced concentrations of a health and wellness hazard; may an outcome in chronic wellness effects, which room adverse effects on a human resulting from long-term exposure come a chemistry (months, years, or decades).
General exhaust ventilationThe basic movement of air out of an area or permit-required confined space by mechanical or natural means.
Hexavalent chromium or chrome 6Hexavalent chromium (CrVI), hex chrome, or chrome 6, is a compound the exists in number of forms and also has many industrial uses, such as in paints, chrome plating, and wood preservatives. Chrome 6 is also produced when “hot work” is excellent on stainless steel. Stainless stole or various other chromiumcontaining steel workers might be exposed to chrome 6 indigenous welding fume.
Local exhaust ventilation (LEV)LEV is a kind of engineering control that encloses the material, equipment, or procedure as lot as feasible and removes process emission prior to its escape into the worker’s breathing zone.
LEV hood The primary role of the LEV hood is to create an air flow that will capture the contaminant at its resource and relocate it right into the exhaust duct.
Objective data Air surveillance data native industry-wide surveys demonstrating chrome 6 exposures linked with a specific product and specific process. Data must reflect workplace conditions that closely reflect the employer’s operation.
OxidizeTo integrate with oxygen; to rise the hopeful charge or valence the an facet by remove electrons.
Permissible exposure limit (PEL) The quantity of an airborne chemical, toxic substance, or various other harmful agent that must not it is in exceeded. The regulatory borders for this airborne chemicals or toxicity substances are commonly reported as an 8-hour, timeweighted median (TWA). The PEL-TWA because that chrome 6 is 5 micrograms every cubic meter of wait (5 μg/m3).
Ventilation Providing, circulating, or exhausting air right into or out of a space or one area.
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Video exposure surveillance (VEM)A tool that measures and also records an employee’s exposure come a contaminant (in this case, complete particulate), utilizing a direct reading instrument, and at the same time records workplace tasks (in this case, warm work) on video.
|ANSI||American national Standards Institute|
|DOSH||Division of occupational Safety and Health|
|HEPA||High effectiveness Particulate Air|
|HexChEC||Hexavalent Chromium Exposure Control|
|HVAC||Heating Ventilating and also Air Conditioning|
|L&I||Washington State room of labor & Industries|
|LEV||Local Exhaust Ventilation|
|MSDS||Material safety Data Sheets|
|NIOSH||National institute for work Safety and also Health|
|OSHA||Occupational Safety and also Health Administration|
|PAPR||Powered Air-Purifying Respirator|
|PEL||Permissible Exposure Limit|
|SAR||Supplied wait Respirator|
|VEM||Video Exposure Monitoring|
American Welding culture (AWS) Terminology
|CAC||Carbon Arc Cutting, additionally known as gouging or scarfing|
|FCAW||Flux main point Arc Welding, sometimes well-known as double shield or hole wire MIG|
|GMAW||Gas steel Arc Welding, or MIG|
|GTAW||Gas Tungsten Arc Welding, or TIG|
|MIG||Manual Inert Gas|
|PAC||Plasma Arc Cutting|
|SAW||Submerged Arc Welding|
|SMAW||Shielded metal Arc Welding, or stick|
|TIG||Tungsten Inert Gas|