Fire Fighter Fatality Investigation and Prevention Program

Firefighter Exposure to Antimony FAQs

Antimony exposure among firefighters: frequently asked questions regarding the NIOSH health hazard evaluation in Florida, February 2009

What is antimony?

Antimony is a silver-white metal that is found at very low levels throughout the environment, including air, soil, and food. It is used in the production of ceramics, glass, paints, fireworks, and batteries. Antimony compounds, particularly antimony oxides, are used as flame retardants in textiles, plastics, rubber, adhesives, and paper.

What health effects can antimony cause?

Overexposure to antimony trioxide can cause irritation to the skin, eyes, nose, and respiratory tract. When ingested, it may also result in nausea, vomiting, abdominal pain, and diarrhea. Toxicity from acute or chronic exposure to antimony trioxide in industry is rare. According to the International Agency for Research on Cancer, the evidence that antimony trioxide can cause cancer in humans is inadequate, but there is some evidence that it can cause cancer in laboratory animals.

Why did NIOSH test the firefighters for antimony exposure?

NIOSH was asked by the Boca Raton Fire Rescue Services Chief to determine whether firefighters had absorbed antimony through their skin from wearing uniform pants made from FireWear® fabric, whose FFR® (Fibrous Flame Retardant) fibers contain antimony trioxide for its flame retarding properties.

Why were firefighters concerned about antimony exposure?

Prior to NIOSH’s involvement, and prompted by unexplained health symptoms in one firefighter, a group of firefighters in Florida had been tested for antimony exposure using hair analysis. The hair tests suggested high antimony levels.

Which firefighters did NIOSH evaluate?

NIOSH investigators evaluated 20 Boca Raton Fire Rescue Services firefighters who had not worn pants containing antimony for the prior four months. NIOSH investigators also evaluated 42 Tamarac Fire Rescue firefighters, who had worn pants containing antimony in the previous two weeks.

How did NIOSH test the firefighters?

NIOSH investigators visited the two fire departments in Florida on February 3-6, 2009. They surveyed participants about personal characteristics, work history, and possible sources of exposure to antimony. They also collected urine samples to measure antimony levels. The urine samples were analyzed at the Centers for Disease Control and Prevention’s (CDC) National Center for Environmental Health Laboratory.

What did NIOSH find?

The urine levels of antimony for all the firefighters tested were not elevated regardless of whether or not they had been wearing uniform pants made from FireWear® fabric. The levels were similar to the urine levels of antimony found in the U.S. population. NIOSH investigators concluded that wearing the pants containing antimony trioxide does not cause elevated levels of antimony in the bodies of firefighters.

Why did NIOSH perform urine testing instead of hair testing?

Urine testing is the most accurate, reliable, and valid test method for measuring antimony levels in the body. Hair testing is not a validated method for heavy metals testing (which includes antimony), and is not recommended by the American Medical Association (AMA) or CDC’s sister agency, the Agency for Toxic Substances and Diseases Registry.

What are the normal levels for urine antimony?

CDC has established ranges for urine levels of antimony in the U.S. population: 0.120─0.364 micrograms/ gram creatinine. This information helps scientists assess whether antimony levels in specific groups are unusual. Similar information is not available for levels of antimony in hair.

Why is hair testing not an accepted method?

NIOSH investigators believe results from hair analysis are unreliable. Accepted standards on methods for collection, storage, and analysis of hair are lacking. Problems also exist with the regulation and certification of laboratories conducting hair analysis. It has been shown that different laboratories can report different results for hair samples collected from the same person. In addition, hair analysis cannot distinguish between internal exposure (substances inside the body) and external exposure (substances that might stick to the hair, like those in hair care products).

Will NIOSH test the pants?

NIOSH investigators do not think that testing the pants is necessary. First, if antimony was being released from the pants and absorbed through the skin, the urine tests would have indicated that firefighters wearing the pants had levels higher than 1) the U.S. population and 2) the firefighters not wearing the pants. Our results showed no differences between these groups. Second, a private technical consulting and engineering firm has tested the fiber in the past. They concluded that antimony trioxide exposures associated with use of clothing made from these fibers comply with the requirements of California’s Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65).

Are the pants containing antimony safe?

NIOSH investigators consider the pants containing antimony to be safe to wear. They recommend that fire departments issue and firefighters wear station uniforms that comply with the National Fire Protection Association (NFPA) 1975 Standard. The pants made from FireWear® fabric are one type of pants that meet this standard. NIOSH investigators also recommend that firefighters follow garment label instructions when laundering station uniforms.

The garment labels suggest low temperature washing and laundering without chlorine bleach. Is this to prevent release of antimony?

No. The garment care instructions are consistent with instructions for fabrics containing cotton and FFR® fibers and ensure that the garment remains durable and does not lose color.

Is NIOSH planning to conduct further evaluation?

NIOSH investigators do not think further evaluation of this issue is needed. The final reports of the NIOSH evaluation is currently being prepared and will be available at: http://www.cdc.gov/niosh/hhe/.