In February of this year, OSHA published an amendment to several sections of 29 CFR 1910. These changes address workers’ exposure to hexavalent chromium (Chromium VI), and include three new sections. This new ruling became effective in March, and the first compliance deadline is November 27, 2006.

Following is a brief overview of the changes and how it will affect respiratory protection for your workers who may be exposed to hexavalent chromium. For a complete copy of the OSHA amendment refer to the Federal Register, Document 71:10099-10385.

Hex chrome overview

Hexavalent chromium is chromium with a valence of positive six, in any form and in any compound, also referred to as Cr(VI). Chromium hexavalent Cr(VI) compounds, often called hexavalent chromium, exist in several forms. Chromates are often used as pigments for photography, and in pyrotechnics, dyes, paints, inks and plastics. They can also be used for stainless steel production, textile dyes, wood preservation, leather tanning and as anti-corrosion coatings.

There are several health risks to long-term exposure to hexavalent chromium including lung cancer. Other risks involve problems to eyes, respiratory tract, skin and kidney.

Prior to this standard revision, the PEL (Permissible Exposure Limit) as stated in 29 CFR 1910.1000 Table Z had a ceiling value of 100 µg/m3 (100 microns per cubic meter) measured as chromium (VI) and reported as chromium anhydride (CrO3). The amount of chromium (VI) in the anhydride compound equates to a PEL of 52 µg/m3. This ceiling limit applies to all forms of hexavalent chromium, including chromium acid and chromates, lead chromate and zinc chromate. The PEL for hexavalent chromium in the construction industry was 100 µg/m3 as a time weighted average (TWA) PEL, which also equates to a PEL of 52 µg/m3.

With these amendments, a PEL for chromium (VI) for general industry, shipyards and the construction industry is established at 5 µg/m3. The new ruling also amends Table Z to reflect this change.

The amended standards are:

1910 Safety & Health Regulations for General Industry

1915 Occupational Safety and Health Standards for Shipyard Employment

1917 Marine Terminals

1918 Safety and Health Regulations for Longshoring

1926 Safety & Health Regulations for Construction

The three new sections are: 1910.1026; 1915.1026; and 1926.1126.

Where hex chrome is used

OSHA has identified as many as 30 industries where hexavalent chromium Cr(VI) is used and estimates approximately one million workers are exposed to Cr(VI) on a regular basis. Industries include: chromate ore; electroplating; welding, specifically stainless steel (including shipyards); painting (including aerospace industry); chromate pigment production and use; steel mills; and iron and steel foundries.

Applications where Cr(VI) may be found include:

Welding: Stainless has a high chrome content of 10 percent to 40 percent.

Metallurgical: Chromium is used to produce stainless steel, alloy steel and nonferrous alloys.

Chemical industry: It’s used in pigments, metal plating and chemical synthesis as ingredients and catalysts. It’s found in high-quality pigments in textile dyes, paints, inks, glass and plastics.

Portland cement: Chromium is not intentionally added to Portland cement but is often present as an impurity.

Protect your workers

Employers first need to conduct a site assessment and determine their employees’ level of exposure to hexavalent chromium. If the worksite exposure is found to be above the permissible level, then the employer should attempt to engineer out the contaminant exposure. If that is not feasible, then respiratory protection must be provided.

Site assessment: Determine the employees’ 8-hour time weighted average exposure to Cr(VI). If it is below the PEL of 5 µg/m3 then respiratory protection is not required. If the TWA exposure is at or above the PEL of 5 µg/m3 implement engineering controls to bring the exposure down to less than the PEL, or if engineering controls are unfeasible, provide respiratory protection as part of a complete respiratory protection program.

Engineering controls: Lower the exposure so it is below the PEL through engineering controls and/or workplace practices. These include: increasing ventilation or using other methods of decreasing contaminant levels; changing the method of manufacture and/or materials used to eliminate or decrease exposure to Cr(VI); or changing workers’ schedules so they are not exposed to Cr(VI) for extended periods, thus bringing an individual’s TWA exposure to Cr(VI) below the PEL.

Exception to the requirement: Because of the difficulty in establishing engineering controls in the aerospace industry, aerospace employers only need to bring the worksite concentrations for Cr(VI) to or below 25 µg/m3, or five times the PEL. As with all industries, respirators are to be used to protect workers when the exposure is above the PEL.

Provide respirators: When the exposure is above the PEL and engineering controls are either inadequate in lowering the exposure to below the PEL, or if engineering controls are unfeasible, then respiratory protection shall be provided, as follows.

<2.5 µg/m3 (<0.0025 mg/m3) ; under the action level — no respiratory protection is required.

<5 µg/m3 (<0.005 mg/m3) ; under the PEL — no respiratory protection is required.

5 µg/m3 to <50 µg/m3 (0.005 to <0.05 mg/m3) ; worksite concentrations up to 10 times the PEL — use air-purifying half mask with P100 filters. (Note: Cr(VI) can irritate the eyes, and direct contact with the eyes may cause permanent damage. A full facepiece respirator will provide eye and face protection in addition to respiratory protection.)

50 µg/m3 to <125 µg/m3 (0.05 to <0.125 mg/m3) ; worksite concentrations up to 25 times the PEL — use PAPR loose fitting facepiece with HEPA filters.

125 µg/m3 to <250 µg/m3 (0.125 to <0.25 mg/m3) ; worksite concentrations up to 50 times the PEL — use:
_ air-purifying full facepiece with P100 filters
_ PAPR half mask with HEPA filters, or
_ supplied air half mask.

250 µg/m3 to <5,000 µg/m3 (0.25 to <5 mg/m3) ; worksite concentrations up to 1,000 times the PEL — use:
_ PAPR full facepiece or hood with HEPA filters, or
_ Supplied air full facepiece or hood.

>5,000 µg/m3 or unknown (>5 mg/m3) — use pressure demand airline with egress or self-contained breathing apparatus (SCBA).

Sidebar: Hex Chrome compliance deadlines

November 27, 2006 (9 months from date of Final Rule Publication): Applies to employers with 20 or more employees.

May 30, 2007 (15 months from date of Final Rule Publication): Applies to employers with 19 or fewer employees.
_ For both of the above deadlines, all obligations of the new section applicable to the employer’s industry must be met, except engineering controls.

May 31, 2010 (3 years and 3 months from date of Final Rule Publication): Applies to all employers. _ Engineering controls, if feasible, must be in place.