Urine testing of Boston office workers found biomarker traces of a potentially harmful flame retardant chemical called TDCPP, which is commonly found in polyurethane foam furniture and baby products and can reduce male fertility.

Boston University School of Public Health researchers wanted to evaluate the investigate the pervasiveness of the flame retardant chemical chlorinated tris (1,3-dichloro-2-propyl) phosphate, also known as "chlorinated tris" or TDCPP, in the environments of average Bostonian office workers.

They recruited 31 healthy adults- 26 women and 5 men- who lived in the Boston area and worked at least 18 hours per week in an enclosed office. The participants provided urine samples and dust samples from their homes, vehicles, and offices.

The results showed that TDCPP was present in 99 percent of dust samples from participants' indoor environments, with much higher concentrations in older office buildings and vehicles than in newer office buildings and homes.

Metabolites of the flame retardant chemical were present in all the office workers' urine samples, though they were likely to have much higher concentrations of TDCPP metabolites in their urine if they worked in older office buildings.

"Overall, our findings suggest that exposure to TDCPP in the work environment is one of the contributors to the personal exposure for office workers," said the research team.

TDCPP was removed from children's pajamas in the early 1980s due to concerns about its toxicity, but is still a common additive in polyurethane foam used in upholstered furniture, and in many foam baby products. As this study indicates, it can gradually leach out of products and attach to dust, easily leading to human exposure.

The human health effects of TDCPP in the concentrations found in this study are still unclear, though evidence is not encouraging. In 2011, the State of California added the flame retardant chemical to its Proposition 65 list of chemicals that cause cancer.

In vitro studies suggest that the chemical can be toxic to brain cells, and that increased concentrations in household dust were associated with decreased semen quality and reduced thyroxine in men, which can have negative effects on fertility and thyroid function. Animal studies show that TDCPP is rapidly absorbed through the skin and digestive system, and absorption is likely to be similarly quick in humans.

The City of Boston has strict fire retardant regulations for office furniture, but not for residential furniture- a difference that is likely related to the higher TDCPP concentrations in office dust samples. The researchers hope that revised furniture flammability standards could eventually reduce the need for flame retardant chemicals in polyurethane foam.

"It is currently very difficult to avoid flame retardants," said Courtney Carignan, an environmental health doctoral candidate at BU who co-authored the study. "Hopefully, better options will become available in the near future."

The research team advises office workers to avoid TDCPP contamination by washing your hands, especially before eating. Office buildings with polyurethane furniture should also have good ventilation and dust control, and air purifiers can help reduce individual exposure.

They offered several possible reasons for the difference in TDCPP concentrations between older and newer office buildings. Newer office buildings might have been more likely to contain newer furniture without TDCPP, or with different (possibly still harmful) flame retardant chemicals. More efficient ventilation or HVAC systems might have been more efficient in removing dust. It's also possible that TDCPP in newer office buildings simply did not yet have enough time to migrate out of furniture.

The researchers hope to conduct more research on TDCPP exposure:

"Further research is needed to confirm specific exposure sources (e.g., polyurethane foam), determine the importance of exposure in other microenvironments such as homes and vehicles, and address the inhalation and dermal exposure pathways."

The study was published in the journal Environment International.