3M is providing information to help its customers meet requirements specified in the new hexavalent chromium standard released Feb. 28 by the Occupational Safety and Health Administration (OSHA).

OSHA published the final Hexavalent Chromium [Cr(VI)] Standard in three versions— General Industry (1910.1026), Construction (1926.1126) and Shipyards (1915.1026). The requirements of each standard are very similar.

Chromium is a metal used in alloys, in chrome plating and as an additive for coatings. Chromium occurs mainly in three forms:

Metallic chromium (CrO) is a steel gray solid with a high melting point that is used to make steel and other alloys.

Trivalent chromium (CrIII) is a naturally occurring element that is used industrially for brick linings in high temperature furnaces and to make metals, metal alloys and chemical compounds.

And hexavalent chromium [Cr(VI)], the form covered under the new standard. Hexavalent chromium is commonly produced by industrial processes.

Common sources of exposure to chromium include welding and cutting stainless steel, the manufacturing of inorganic pigments and coatings and electroplating. OSHA lists 32 industries that are affected including welding. The complete list of industries OSHA identified is available at OSHA's website: www.osha.gov

Permissible exposure limits is 5 micrograms per cubic meter (5g/m), and these exposure limits, that require respiratory protection and engineering controls are to take effect on the following dates:

Employers with more than 20 employees on November 27, 2006

Employers with fewer than 20 employees on May 30, 2007

Engineering controls must be in place for all places of employment by May 31, 2010.

Hexavalent chromium exposure from any source is covered except exposures from Portland Cement and the application of regulated pesticides.

The previous permissible exposure limits was 52 micro-grams per cubic meter (52 g/m).

A primary reason for announcing the new standard is the realization that much lower levels of the substance than previously thought can have serious health implications.

In announcing the new standard, Jonathan Snare, acting assistant secretary, OSHA, said the new permissible exposure limits "is the lowest level that is feasible both technologically and economically."

Respiratory protection requirements are the same in all three standards general industry, construction and shipyards. Respirators are required whenever exposure levels exceed the permissible exposure limits, as follows:

While engineering and work practice controls are under development.

During maintenance and repair activities for which engineering and work practice controls are not feasible.

When all feasible engineering and work practice controls are implemented but are still not sufficient to reduce exposure to or below the permissible exposure limits.

When employees are exposed above the permissible exposure limits for fewer than 30 days per year and the employer has elected not to implement engineering and work practice controls.

And in emergencies. There is no respirator selection table specific to hexavalent chromium standards. However, 3M recommends the following, which is consistent with current respirator selection:

N95 filters may be used where no oil aerosols are present.

R or P95 filters may be used where oil aerosols are present. Refer to packaging for time use limitations.

Elastomeric or filtering half facepieces with class 95 particulate filters may be used up to 10 times the permissible exposure limits.

Full facepiece respirators with appropriate filters may be used to 10 times the permissible exposure limits when qualitatively fit tested or up to 50 times the permissible exposure limits when quantitatively fit tested.

Loose-fitting facepieces may be used to 25 times the permissible exposure limits.

Tight-fitting facepieces may be used to 1000 times the permissible exposure limits.

Tight-fitting full facepieces, hoods and helmets with supplied air or powered air purifying respirators may be used to 1000 times the permissible exposure limits.

Additional information is available at www.3M.com/OccSafety for product information.

To contact an AIHA accredited laboratory or an industrial hygienist for assistance with exposure assessment, go to www.aiha.org and select Laboratories or Consultants. For a complete copy of the standard, please refer to OSHA's website: www.osha.gov