SAFETY 101: HEALTH EFFECTS OF HEXAVALENT CHROMIUMHexavalent chromium is a toxic form of the element chromium. Hexavalent chromium compounds are man-made and widely used in many different industries.|
Some major industrial sources of hexavalent chromium are:
| ||chromate pigments in dyes, paints, inks, and plastics|
| ||chromates added as anti-corrosive agents to paints, primers and other surface coatings|
| ||chrome plating by depositing chromium metal onto an itemís surface using a solution of chromic acid|
| ||particles released during smelting of ferrochromium ore|
| ||fumes from welding stainless steel or nonferrous chromium alloys|
| ||impurity present in portland cement.|
How hexavalent chromium can harm employees
Workplace exposure to hexavalent chromium may cause the following health effects:
| ||lung cancer in workers who breathe airborne hexavalent chromium|
| ||irritation or damage to the nose, throat, and lung (respiratory tract) if hexavalent chromium is breathed at high levels |
| ||irritation or damage to the eyes and skin if hexavalent chromium contacts these organs in high concentrations.|
How hexavalent chromium affects the nose, throat and lungs
Breathing in high levels of hexavalent chromium can cause irritation to the nose and throat. Symptoms may include runny nose, sneezing, coughing, itching and a burning sensation.
Repeated or prolonged exposure can cause sores to develop in the nose and result in nosebleeds. If the damage is severe, the nasal septum (wall separating the nasal passages) develops a hole in it (perforation).
Breathing small amounts of hexavalent chromium even for long periods does not cause respiratory tract irritation in most people. Some employees become allergic to hexavalent chromium so that inhaling chromate compounds can cause asthma symptoms such as wheezing and shortness of breath.
How hexavalent chromium affects the skin
Some employees can also develop an allergic skin reaction, called allergic contact dermatitis. This occurs from handling liquids or solids containing hexavalent chromium. Once an employee becomes allergic, brief skin contact causes swelling and a red, itchy rash that becomes crusty and thickened with prolonged exposure. Allergic contact dermatitis is long-lasting and more severe with repeated skin contact.
Direct skin contact with hexavalent chromium can cause a non-allergic skin irritation. Contact with non-intact skin can also lead to chrome ulcers. These are small crusted skin sores with a rounded border. They heal slowly and leave scars.
How employees can be exposed to hexavalent chromium
Employees can inhale airborne hexavalent chromium as a dust, fume or mist while:
| ||producing chromate pigments and powders; chromic acid; chromium catalysts, dyes, and coatings|
| ||working near chrome electroplating|
| ||welding and hotworking stainless steel, high chrome alloys and chrome-coated metal |
| ||applying and removing chromate-containing paints and other surface coatings. |
Steps OSHA has taken to protect employees from health hazards caused by hexavalent chromium
The new OSHA workplace standard requires employers to:
| ||limit eight-hour time-weighted average hexavalent chromium exposure in the workplace to 5 micrograms or less per cubic meter of air.|
| ||perform periodic monitoring at least every 6 months if initial monitoring shows employee exposure at or above the action level (2.5 micrograms per cubic meter of air calculated as an 8-hour time-weighted average).|
| ||provide appropriate personal protective clothing and equipment when there is likely to be a hazard present from skin or eye contact.|
| ||implement good personal hygiene and housekeeping practices to prevent hexavalent chromium exposure.|
| ||prohibit employee rotation as a method to achieve compliance with the exposure limit (PEL).|
| ||provide respiratory protection as specified in the standard.|
| ||make available medical examinations to employees within 30 days of initial assignment, annually, to those exposed in an emergency situation, to those who experience signs or symptoms of adverse health effects associated with hexavalent chromium exposure, to those who are or may be exposed at or above the action level for 30 or more days a year, and at termination of employment.|
A fact sheet about the hexavalent chromium (Cr(VI) standard is available from Minnesota OSHA at http://www.dli.mn.gov/OSHA/PDF/fact_hexchrom.pdf. All provisions of the standard, except engineering controls, went into effect November 2006 for employers with 20 or more employees and will be effective May 30, 2007, for employers with fewer than 20 employees. All employers must implement engineering controls by May 31, 2010.