29 CFR § 1910.1026 - Chromium (VI).
(2) Exposures that occur in the application of pesticides regulated by the Environmental Protection Agency or another Federal government agency (e.g., the treatment of wood with preservatives);
(3) Exposures to portland cement; or
(4) Where the employer has objective data demonstrating that a material containing chromium or a specific process, operation, or activity involving chromium cannot release dusts, fumes, or mists of chromium (VI) in concentrations at or above 0.5 µgm/m 3 as an 8-hour time-weighted average (TWA) under any expected conditions of use.
(b) Definitions. For the purposes of this section the following definitions apply:
Action level means a concentration of airborne chromium (VI) of 2.5 micrograms per cubic meter of air (2.5 µgm/m 3) calculated as an 8-hour time-weighted average (TWA).
Assistant Secretary means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.
Chromium (VI) [hexavalent chromium or Cr(VI)] means chromium with a valence of positive six, in any form and in any compound.
Director means the Director of the National Institute for Occupational Safety and Health (NIOSH), U.S. Department of Health and Human Services, or designee.
Emergency means any occurrence that results, or is likely to result, in an uncontrolled release of chromium (VI). If an incidental release of chromium (VI) can be controlled at the time of release by employees in the immediate release area, or by maintenance personnel, it is not an emergency.
Employee exposure means the exposure to airborne chromium (VI) that would occur if the employee were not using a respirator.
High-efficiency particulate air [HEPA] filter means a filter that is at least 99.97 percent efficient in removing mono-dispersed particles of 0.3 micrometers in diameter or larger.
Historical monitoring data means data from chromium (VI) monitoring conducted prior to May 30, 2006, obtained during work operations conducted under workplace conditions closely resembling the processes, types of material, control methods, work practices, and environmental conditions in the employer's current operations.
Objective data means information such as air monitoring data from industry-wide surveys or calculations based on the composition or chemical and physical properties of a substance demonstrating the employee exposure to chromium (VI) associated with a particular product or material or a specific process, operation, or activity. The data must reflect workplace conditions closely resembling the processes, types of material, control methods, work practices, and environmental conditions in the employer's current operations.
Physician or other licensed health care professional [PLHCP] is an individual whose legally permitted scope of practice (i.e., license, registration, or certification) allows him or her to independently provide or be delegated the responsibility to provide some or all of the particular health care services required by paragraph (k) of this section.
(c) Permissible exposure limit (PEL). The employer shall ensure that no employee is exposed to an airborne concentration of chromium (VI) in excess of 5 micrograms per cubic meter of air (5 µgm/m 3), calculated as an 8-hour time-weighted average (TWA).
(d) Exposure determination -
(1) General. Each employer who has a workplace or work operation covered by this section shall determine the 8-hour TWA exposure for each employee exposed to chromium (VI). This determination shall be made in accordance with either paragraph (d)(2) or paragraph (d)(3) of this section.
(2) Scheduled monitoring option.
(i) The employer shall perform initial monitoring to determine the 8-hour TWA exposure for each employee on the basis of a sufficient number of personal breathing zone air samples to accurately characterize full shift exposure on each shift, for each job classification, in each work area. Where an employer does representative sampling instead of sampling all employees in order to meet this requirement, the employer shall sample the employee(s) expected to have the highest chromium (VI) exposures.
(ii) If initial monitoring indicates that employee exposures are below the action level, the employer may discontinue monitoring for those employees whose exposures are represented by such monitoring.
(v) If periodic monitoring indicates that employee exposures are below the action level, and the result is confirmed by the result of another monitoring taken at least seven days later, the employer may discontinue the monitoring for those employees whose exposures are represented by such monitoring.
(vi) The employer shall perform additional monitoring when there has been any change in the production process, raw materials, equipment, personnel, work practices, or control methods that may result in new or additional exposures to chromium (VI), or when the employer has any reason to believe that new or additional exposures have occurred.
(3) Performance-oriented option. The employer shall determine the 8-hour TWA exposure for each employee on the basis of any combination of air monitoring data, historical monitoring data, or objective data sufficient to accurately characterize employee exposure to chromium (VI).
(4) Employee notification of determination results.
(i) Within 15 work days after making an exposure determination in accordance with paragraph (d)(2) or paragraph (d)(3) of this section, the employer shall individually notify each affected employee in writing of the results of that determination or post the results in an appropriate location accessible to all affected employees.
(ii) Whenever the exposure determination indicates that employee exposure is above the PEL, the employer shall describe in the written notification the corrective action being taken to reduce employee exposure to or below the PEL.
(5) Accuracy of measurement. Where air monitoring is performed to comply with the requirements of this section, the employer shall use a method of monitoring and analysis that can measure chromium (VI) to within an accuracy of plus or minus 25 percent (±25%) and can produce accurate measurements to within a statistical confidence level of 95 percent for airborne concentrations at or above the action level.
(6) Observation of monitoring.
(i) Where air monitoring is performed to comply with the requirements of this section, the employer shall provide affected employees or their designated representatives an opportunity to observe any monitoring of employee exposure to chromium (VI).
(ii) When observation of monitoring requires entry into an area where the use of protective clothing or equipment is required, the employer shall provide the observer with clothing and equipment and shall assure that the observer uses such clothing and equipment and complies with all other applicable safety and health procedures.
(e) Regulated areas -
(1) Establishment. The employer shall establish a regulated area wherever an employee's exposure to airborne concentrations of chromium (VI) is, or can reasonably be expected to be, in excess of the PEL.
(2) Demarcation. The employer shall ensure that regulated areas are demarcated from the rest of the workplace in a manner that adequately establishes and alerts employees of the boundaries of the regulated area.
(f) Methods of compliance -
(1) Engineering and work practice controls.
(i) Except as permitted in paragraph (f)(1)(ii) and paragraph (f)(1)(iii) of this section, the employer shall use engineering and work practice controls to reduce and maintain employee exposure to chromium (VI) to or below the PEL unless the employer can demonstrate that such controls are not feasible. Wherever feasible engineering and work practice controls are not sufficient to reduce employee exposure to or below the PEL, the employer shall use them to reduce employee exposure to the lowest levels achievable, and shall supplement them by the use of respiratory protection that complies with the requirements of paragraph (g) of this section.
(ii) Where painting of aircraft or large aircraft parts is performed in the aerospace industry, the employer shall use engineering and work practice controls to reduce and maintain employee exposure to chromium (VI) to or below 25 µgm/m 3 unless the employer can demonstrate that such controls are not feasible. The employer shall supplement such engineering and work practice controls with the use of respiratory protection that complies with the requirements of paragraph (g) of this section to achieve the PEL.
(iii) Where the employer can demonstrate that a process or task does not result in any employee exposure to chromium (VI) above the PEL for 30 or more days per year (12 consecutive months), the requirement to implement engineering and work practice controls to achieve the PEL does not apply to that process or task.
(g) Respiratory protection -
(1) General. Where respiratory protection is required by this section, the employer must provide each employee an appropriate respirator that complies with the requirements of this paragraph. Respiratory protection is required during:
(i) Periods necessary to install or implement feasible engineering and work practice controls;
(ii) Work operations, such as maintenance and repair activities, for which engineering and work practice controls are not feasible;
(iv) Work operations where employees are exposed above the PEL for fewer than 30 days per year, and the employer has elected not to implement engineering and work practice controls to achieve the PEL; or
(2) Respiratory protection program. Where respirator use is required by this section, the employer shall institute a respiratory protection program in accordance with § 1910.134, which covers each employee required to use a respirator.
(h) Protective work clothing and equipment -
(1) Provision and use. Where a hazard is present or is likely to be present from skin or eye contact with chromium (VI), the employer shall provide appropriate personal protective clothing and equipment at no cost to employees, and shall ensure that employees use such clothing and equipment.
(2) Removal and storage.
(i) The employer shall ensure that employees remove all protective clothing and equipment contaminated with chromium (VI) at the end of the work shift or at the completion of their tasks involving chromium (VI) exposure, whichever comes first.
(ii) The employer shall ensure that no employee removes chromium (VI)-contaminated protective clothing or equipment from the workplace, except for those employees whose job it is to launder, clean, maintain, or dispose of such clothing or equipment.
(iii) When contaminated protective clothing or equipment is removed for laundering, cleaning, maintenance, or disposal, the employer shall ensure that it is stored and transported in sealed, impermeable bags or other closed, impermeable containers.
(iv) The employer shall ensure that bags or containers of contaminated protective clothing or equipment that are removed from change rooms for laundering, cleaning, maintenance, or disposal are labeled in accordance with the requirements of the Hazard Communication Standard, § 1910.1200.
(3) Cleaning and replacement.
(ii) The employer shall prohibit the removal of chromium (VI) from protective clothing and equipment by blowing, shaking, or any other means that disperses chromium (VI) into the air or onto an employee's body.
(iii) The employer shall inform any person who launders or cleans protective clothing or equipment contaminated with chromium (VI) of the potentially harmful effects of exposure to chromium (VI) and that the clothing and equipment should be laundered or cleaned in a manner that minimizes skin or eye contact with chromium (VI) and effectively prevents the release of airborne chromium (VI) in excess of the PEL.
(i) Hygiene areas and practices -
(1) General. Where protective clothing and equipment is required, the employer shall provide change rooms in conformance with 29 CFR 1910.141. Where skin contact with chromium (VI) occurs, the employer shall provide washing facilities in conformance with 29 CFR 1910.141. Eating and drinking areas provided by the employer shall also be in conformance with § 1910.141.
(2) Change rooms. The employer shall assure that change rooms are equipped with separate storage facilities for protective clothing and equipment and for street clothes, and that these facilities prevent cross-contamination.
(3) Washing facilities.
(ii) The employer shall ensure that employees who have skin contact with chromium (VI) wash their hands and faces at the end of the work shift and prior to eating, drinking, smoking, chewing tobacco or gum, applying cosmetics, or using the toilet.
(4) Eating and drinking areas.
(i) Whenever the employer allows employees to consume food or beverages at a worksite where chromium (VI) is present, the employer shall ensure that eating and drinking areas and surfaces are maintained as free as practicable of chromium (VI).
(ii) The employer shall ensure that employees do not enter eating and drinking areas with protective work clothing or equipment unless surface chromium (VI) has been removed from the clothing and equipment by methods that do not disperse chromium (VI) into the air or onto an employee's body.
(5) Prohibited activities. The employer shall ensure that employees do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in regulated areas, or in areas where skin or eye contact with chromium (VI) occurs; or carry the products associated with these activities, or store such products in these areas.
(j) Housekeeping -
(1) General. The employer shall ensure that:
(i) All surfaces are maintained as free as practicable of accumulations of chromium (VI).
(ii) All spills and releases of chromium (VI) containing material are cleaned up promptly.
(2) Cleaning methods.
(ii) Dry shoveling, dry sweeping, and dry brushing may be used only where HEPA-filtered vacuuming or other methods that minimize the likelihood of exposure to chromium (VI) have been tried and found not to be effective.
(A) The compressed air is used in conjunction with a ventilation system designed to capture the dust cloud created by the compressed air; or
(B) No alternative method is feasible.
(3) Disposal. The employer shall ensure that:
(i) Waste, scrap, debris, and any other materials contaminated with chromium (VI) and consigned for disposal are collected and disposed of in sealed, impermeable bags or other closed, impermeable containers.
(ii) Bags or containers of waste, scrap, debris, and any other materials contaminated with chromium (VI) that are consigned for disposal are labeled in accordance with the requirements of the Hazard Communication Standard, 29 CFR 1910.1200.
(k) Medical surveillance -
(C) Exposed in an emergency.
(2) Frequency. The employer shall provide a medical examination:
(3) Contents of examination. A medical examination consists of:
(i) A medical and work history, with emphasis on: Past, present, and anticipated future exposure to chromium (VI); any history of respiratory system dysfunction; any history of asthma, dermatitis, skin ulceration, or nasal septum perforation; and smoking status and history;
(ii) A physical examination of the skin and respiratory tract; and
(iii) Any additional tests deemed appropriate by the examining PLHCP.
(5) PLHCP's written medical opinion.
(A) The PLHCP's opinion as to whether the employee has any detected medical condition(s) that would place the employee at increased risk of material impairment to health from further exposure to chromium (VI);
(C) A statement that the PLHCP has explained to the employee the results of the medical examination, including any medical conditions related to chromium (VI) exposure that require further evaluation or treatment, and any special provisions for use of protective clothing or equipment.
(l) Communication of chromium (VI) hazards to employees -
(1) Hazard communication - general - (i) Chemical manufacturers, importers, distributors and employers shall comply with all requirements of the Hazard Communication Standard (HCS) (§ 1910.1200) for chromium (VI).
(ii) In classifying the hazards of chromium (VI) at least the following hazards are to be addressed: Cancer, eye irritation, and skin sensitization.
(iii) Employers shall include chromium (VI) in the hazard communication program established to comply with the HCS (§ 1910.1200). Employers shall ensure that each employee has access to labels on containers of chromium (VI) and to safety data sheets, and is trained in accordance with the requirements of HCS and paragraph (l)(2) of this section.
(2) Employee information and training.
(A) The contents of this section; and
(m) Recordkeeping -
(1) Air monitoring data.
(ii) This record shall include at least the following information:
(A) The date of measurement for each sample taken;
(B) The operation involving exposure to chromium (VI) that is being monitored;
(C) Sampling and analytical methods used and evidence of their accuracy;
(D) Number, duration, and the results of samples taken;
(E) Type of personal protective equipment, such as respirators worn; and
(2) Historical monitoring data.
(i) Where the employer has relied on historical monitoring data to determine exposure to chromium (VI), the employer shall establish and maintain an accurate record of the historical monitoring data relied upon.
(ii) The record shall include information that reflects the following conditions:
(B) The processes and work practices that were in use when the historical monitoring data were obtained are essentially the same as those to be used during the job for which exposure is being determined;
(C) The characteristics of the chromium (VI) containing material being handled when the historical monitoring data were obtained are the same as those on the job for which exposure is being determined;
(D) Environmental conditions prevailing when the historical monitoring data were obtained are the same as those on the job for which exposure is being determined; and
(E) Other data relevant to the operations, materials, processing, or employee exposures covered by the exception.
(3) Objective data.
(ii) This record shall include at least the following information:
(A) The chromium containing material in question;
(B) The source of the objective data;
(D) A description of the process, operation, or activity and how the data support the determination; and
(4) Medical surveillance.
(ii) The record shall include the following information about the employee:
(B) A copy of the PLHCP's written opinions;
(4) In facilities that become parties to the settlement agreement included in appendix A, engineering controls required by paragraph (f) of this section shall be implemented no later than December 31, 2008.
The parties to this Settlement Agreement (“Agreement”) are the Occupational Safety and Health Administration, United States Department of Labor (“OSHA”), the Surface Finishing Industry Council or its successors (“SFIC”), surface-finishing and metal-finishing facilities which have opted into this Agreement pursuant to paragraph 7 (“Company” or “Companies”), Public Citizen Health Research Group (“HRG”), and the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union (“Steelworkers”).
Whereas, On February 28, 2006, OSHA promulgated a revised hexavalent chromium standard for general industry (“the Standard”) that includes a permissible exposure limit (“PEL”) for hexavalent chromium of 5 micrograms per cubic meter (“μg/m 3”) measured as an 8-hour time-weighted average (“TWA”), and a deadline of May 31, 2010, for employers to come into compliance with this PEL through the implementation of engineering controls. The deadline for compliance with the remaining provisions of the Standard, including those requiring the use of respiratory protection to comply with the PEL, is November 27, 2006, for employers with twenty (20) or more employees, and May 30, 2007, for employers with nineteen (19) or fewer employees. 29 CFR 1910.1026, 71 FR 10100 (Feb. 28, 2006);
Whereas, SFIC filed a Petition for Review of the Standard in the Eleventh Circuit that was consolidated with other Petitions in the Third Circuit (Case No. 06-2272);
Whereas, SFIC filed a Motion for Leave to Intervene in the matter of HRG's Petition for Review in the Third Circuit (Case No. 06-1818), which has been granted;
Now, therefore, the parties to this Agreement do hereby agree to the following terms:
1. Term of this Agreement. This Agreement will be effective upon execution and will expire on May 31, 2010.
2. Accelerated implementation of engineering controls. The Companies agree that in accordance with 29 CFR 1910.1026(f)(1) they will implement those feasible engineering controls necessary to reduce hexavalent chromium levels at their facilities by December 31, 2008, to or below the 5 μg/m 3 PEL. In fulfilling this obligation, the Companies may select from the engineering and work practice controls listed in Exhibit A to this Agreement or adopt any other controls.
3. Compliance plan and monitoring. In accordance with 29 CFR 1910.1026(d)(4)(ii), each Company will prepare, and update as required, a written plan setting forth the specific control steps being taken to reduce employee exposure to or below the PEL by December 31, 2008. In addition, Companies will make an initial exposure determination as required by 29 CFR 1910.1026(d)(1) using either the procedures for personal breathing zone air samples described in 29 CFR 1910.1026(d)(2) or the performance-oriented option described at 29 CFR 1910.1026(d)(3). Thereafter, Companies will conduct periodic monitoring in accordance with the “Scheduled Monitoring Option” provisions at 29 CFR 1910.1026(d)(2) and related provisions at 29 CFR 1910.1026(d)(4)-(6). The Companies agree that upon request compliance plans prepared in accordance with this paragraph, as well as all monitoring results obtained in compliance with this paragraph, will be provided to OSHA, affected employees and employee representatives.
4. Respirator use. The respiratory protection provisions at 29 CFR 1910.1026(f) and (g) will apply to the Companies in accordance with the terms and dates set forth in the Standard, except that prior to December 31, 2008, for Companies that are in compliance with this Agreement, OSHA will enforce those respiratory protection provisions only with respect to employees who fall into one of the following six (6) categories: (1) Employees who are exposed to hexavalent chromium in excess of the PEL while performing tasks described in Exhibit B to this Agreement; (2) through November 30, 2007, employees whose exposures to hexavalent chromium exceed a “respirator threshold” of 20 μg/m 3 (measured as an 8-hour TWA); (3) beginning December 1, 2007, employees whose exposures to hexavalent chromium exceed a “respirator threshold” of 12.5 μg/m 3 (measured as an 8-hour TWA); (4) employees who are exposed to hexavalent chromium and request a respirator; (5) any other employees who are required by the Companies to wear a respirator; and (6) employees with exposures for which respirators were required under the previous hexavalent chromium standard (1910.1000) and any other employees covered by respirator programs in effect on May 30, 2006.
5. Employee information and training. Company employees will be trained pursuant to the provisions of 29 CFR 1910.1026(l)(2). In addition, the Companies agree to train employees in the provisions of this Agreement within sixty (60) days of the Opt-In Date (defined in paragraph 7 of this Agreement). The training regarding this Agreement shall be provided in language the employees can understand.
6. Enforcement. Within thirty (30) days of the execution of this Agreement, OSHA will publish a notice in the Federal Register amending 29 CFR 1910.1026 as follows: (1) A copy of this Agreement will be attached to the Standard as appendix A; (2) a new paragraph, 1910.1026(n)(4), will be added to the Standard, and will read: “In facilities that become parties to the settlement agreement included in appendix A, engineering controls required by paragraph (f) of this section shall be implemented no later than December 31, 2008”; and (3) existing paragraph 1910.1026(n)(3) will be amended to read: “Except as provided in (n)(4), for all employers, engineering controls required by paragraph (f) of this section shall be implemented no later than May 31, 2010.”
7. Opt-In Date for Companies to become parties to this Agreement. The Federal Register notice described in paragraph 6 of this Agreement will provide notice of the provisions of this Agreement, and of the revisions to the Standard described in paragraph 6, and will provide until November 30, 2006, for eligible facilities to become parties to this Agreement, and be subject to all of the duties, obligations, and rights herein. The last date for signing by facilities shall be referred to as the Opt-In Date. The opt in option will be available on a facility by facility basis and only to SFIC members and other surface-finishing and metal-finishing job shop facilities within the jurisdiction of Federal OSHA. (For purposes of this Agreement, a “job shop” is defined as a facility that sells plating or anodizing services to other companies.) Moreover, the terms of this Agreement apply only with respect to the performance of surface-finishing and metal-finishing operations in those facilities. Although this Agreement applies only to facilities within the jurisdiction of Federal OSHA, OSHA will encourage States with OSHA-approved State occupational safety and health plans to either honor and implement the terms of this Agreement, including the amendments to the standard described in paragraph 6, or to take an alternative position, which may include entering into separate arrangements with surface- and metal-finishing job shop facilities (or their representatives) in their jurisdiction.
8. Effect on third parties. Nothing in this Agreement constitutes an admission by SFIC or the Companies that a significant risk of material health impairment exists for hexavalent chromium justifying a reduction of the PEL to 5 μg/m 3. Nor does anything in this Agreement constitute any other admission by SFIC or the Companies for purposes of this litigation or future litigation or standards-setting. This Agreement is not intended to give any rights to any third party except as expressly provided herein.
9. OSHA inspections. OSHA may do monitoring inspections to assess compliance with and progress under this Agreement and the Standard, and nothing in this Agreement limits OSHA's right to conduct inspections at Companies” facilities in accordance with the Occupational Safety and Health Act.
10. Scope of Agreement. The terms of this Agreement apply only in the circumstances and to the Companies specified herein. In entering into this Agreement, OSHA is not making any representations regarding its enforcement policy with respect to either (1) The hexavalent chromium standard as applied to employers who are not parties to this Agreement or (2) any other occupational safety or health standards.
11. Effect of invalidation of the Standard. If the Standard is invalidated, nothing in this Agreement shall prevent the application to SFIC or the Companies of any PEL that is promulgated by OSHA on remand. This Agreement would not foreclose SFIC or the Companies from participating in rulemaking proceedings or otherwise challenging any new PEL promulgated by OSHA on remand.
12. Withdrawal of Petitions and Interventions. SFIC agrees to move to withdraw its Petition for Review in the above-captioned case, Case No. 06-2272, within five (5) working days of the execution of this Agreement. SFIC further will move to dismiss its motion to intervene in Case No. 06-1818 and all other challenges simultaneously with its motion to withdraw in Case No. 06-2272 as Petitioner.
13. Attorneys' fees. Each party agrees to bear its own attorneys' fees, costs, and other expenses that have been incurred in connection with SFIC's Petition for Review, SFIC's intervention in HRG's Petition for Review, and the negotiation of this Agreement up to and including filing of the motions to dismiss.
14. Support of Agreement. In the event that all or any portion of this Agreement is challenged in any forum, the signatories below agree to move to intervene in support of this Agreement.
Agreed to this 25th day of October, 2006.
The Companies agree that work towards the implementation of these available engineering and work practice controls should not be delayed to accommodate their completion by December 31, 2008. The Companies are encouraged to implement from among these controls as soon as practicable.
• Minimize droplet formation. Instruments akin to garden hoses are used to rinse off parts coming out of chemical baths. This causes many small droplets to form, which are easily atomized or vaporized and contribute to airborne chromium concentration. The industry is currently developing ways to minimize the formation of small droplets, dripping, or splashing, possibly by reducing hose pressure.
• Minimize air current flow. Strong air currents across these droplets may contribute to their vaporization, and therefore minimizing air current flow across the droplets may reduce airborne hexavalent chromium levels.
• Slow part speeds as feasible. The speed at which parts are pulled out of a chemical tank causes splashing, which adds to chromium vaporization. By slowing the speed at which parts are taken out of tanks, splashing and vaporization can be minimized. The feasibility of this control must be evaluated in light of the negative effect on productivity.
• Lower surface tension. Lower surface tension in chemical baths leads to fewer drops forming. Chromium baths currently have a surface tension of 35 dynes per centimeter. As a comparison, water has a surface tension of 72 dynes per centimeter. Lowering surface tension further would lead to reduced airborne hexavalent chromium levels.
• Fume suppressants. Fume suppressants create a physical barrier between the chemical bath and the air, which prevents vaporization. Some suppressants, however, may cause pitting or other metal damage, and therefore their use is not always possible.
• Improvement of local exhaust ventilation (LEV) capture efficiency. The majority of electroplating facilities are not air-conditioned. As a result, doors are kept open to let in cool air, but this causes air currents that prevent the LEVs from performing efficiently. The use of fans has a similar effect. Industry is researching how to minimize these air currents so that LEVs can perform as designed. Such methods may include the use of partitions to degrade air current flow, or checklists that may include location and positioning of cross drafts, fans, doors, windows, partitions and process equipment that Companies can use to audit their workplaces in order to improve their capture efficiency.
• Eductors. Many chemical baths are currently mixed via air agitation: Air pipes bubble air into the tank to keep the chemicals mixed and to prevent them from settling. An adverse effect of this agitation is that air bubbles escape at the surface of the tank, resulting in some chromium vaporization. By using eductors (horn-shaped nozzles) in tanks, the chemicals flow from a pump to create solution movement below the surface without the use of air bubbles, and the amount of chromium vaporization can be significantly reduced.
• Liquid Chromium. Dry hexavalent chromium flakes are occasionally added to tanks, which can generate airborne particulates of hexavalent chromium. Adding liquid chromium at or near the surface of a tank would lower airborne chromium levels and reduce splashing from tanks.
• Hydration of flakes before addition. To add liquid chromium to tanks, the dry flakes must be hydrated. Whether this process is performed by chemical suppliers that provide plating solutions to metal finishing companies or by metal finishing companies that have the necessary experience and equipment, appropriate work practices such as mixing techniques must be implemented to minimize the potential airborne levels of hexavalent chromium.
• Better housekeeping. Chrome dust that comes off products that are polished or grinded is actually elemental chromium, not hexavalent chromium, so polishing and grinding contribute little to airborne hexavalent chromium levels. However, Companies should use good housekeeping practices, including wet mopping, and wet wipedowns, to reduce the amount of dust present.
• Improvement and maintenance of existing LEVs. Companies may repair and maintain their current LEVs. Because the final rule indicates that at least 75 percent of the industry is in compliance with the PEL with LEVs working at 40% of capacity, increasing LEV function can materially affect compliance.
• Other methods. Companies are constantly determining best work practices and technological controls through laboratory research and practical experience. Companies will implement other engineering and work practice controls as necessary and as practicable to reduce potential hexavalent chromium workplace exposures.
Some well-known and relatively few, discrete tasks related to metal finishing activities result in potentially higher workplace exposures of hexavalent chromium. Where the applicable PEL for hexavalent chromium is exceeded, respirators shall be worn to conduct the following activities:
(1) Hexavalent chromium chemical additions. In order to have the metal deposited onto the part, hexavalent chromium must be added to the plating tank periodically. This is a discrete activity that involves the addition of either a dry flake of hexavalent chromium chemicals or a liquid solution of hexavalent chromium into the plating tank. Respirators shall be worn during the period it takes to add the hexavalent chromium chemical to the tank.
(2) Hexavalent chromium preparation and mixing. Different mixtures of hexavalent chromium chemicals are needed for different types of chromium plating processes. For example, hard chromium plating can require higher concentrations of hexavalent chromium because a thicker coating and longer plating process may be needed for the critical product quality and performance. Similarly, different types of decorative chromium plating processes may need different levels of hexavalent chromium and other chemicals such as catalysts. These mixtures can be in the form of dry flakes or liquid solutions. All of these different hexavalent chromium chemical mixtures are generally prepared by metal finishing suppliers and distributors. Some metal finishing companies may also prepare hexavalent chromium solutions from the dry flakes prior to addition to the plating tanks. Respirators shall be worn during the period it takes to prepare these hexavalent chromium mixtures and solutions whether the activity is conducted at a chemical supplier or a metal finishing company.
(3) Hexavalent chromium tank cleaning. Occasionally, the tanks used for chromium plating may need to be emptied and cleaned. This process would involve the draining of the solution and then the removal of any residues in the tank. Workers cleaning out these tanks may have to enter the tank or reach into it to remove the residues. Respirators (as well as other appropriate PPE) shall be worn during the period it takes to clean the tanks and prepare them for use again.
(4) Hexavalent chromium painting operations. Some metal finishing operations apply paints with higher concentrations of hexavalent chromium to a line of parts, particularly for aerospace applications when a high degree of corrosion protection is needed for critical product performance. Paints are generally applied in such operations with some type of spray mechanism or similar dispersion practice. In some instances, it may be difficult to keep workplace exposures below the PEL for such paint spraying activities. Respirators shall be worn during such spray painting operations.