Phosphate flame retardants: Bad to the bone?

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If you go to the CDC’s ToxGuide it will tell you that data suggest Phosphate Ester Flame Retardants are widely distributed throughout the human body. You’ll also find this:

Normal human levels? No data available
Biomarkers? There are no biomarkers that can be used to quantify exposure…
Level in air? No data…
Levels in sediment and soil? No data…

Read ToxFAQs and you’ll find “there is not enough data” to determine if they produce cancer in humans (though increases in cancers have been observed in lab animals) and “no studies have been conducted to examine the toxicity … in children”.

We knew this about phosphate flame retardants –
A 2012 study exposing rats to Firemaster 550 (FM550) suggested it disrupts hormones and may cause obesity. FM550 contains phosphate esters and brominated flame retardants. It may be the most commonly used flame retardant in furniture foam. A 2013 study found a component of FM550 called TPP (triphenyl phosphate) in 98% of house dust samples analyzed.

Now we’re learning this –
A study published in Environmental Health Perspectives, shows Firemaster 550 binds to and activates a receptor that is the master regulator of fat formation. FM550, and its phosphate component TPP in particular, induce fat formation and suppress bone and cartilage formation. That’s a bad trade.

flickr @ Alan Boyde Wellcome Images

Photo credit: flickr @ Alan Boyde
Bone with osteoporosis

“In the present study we observed that FM550 and TPP could divert bone marrow [stem cell] differentiation away from bone formation and toward [fat cell] differentiation.”

In other words, in the presence of FM550 and TPP, fat actually forms in bone marrow replacing bone latticework. A researcher put it this way – when fat is made, bone is not.

We’re also learning this –
“Phosphate flame retardants (PFRs) are abundant and found at the highest concentrations” but they are “poorly studied”. So, researchers at the Silent Spring Institute and the University of Antwerp developed a method of testing for them. They collected urine samples from 16 California adults and dust samples from their homes. The study found breakdown products for six PFRs in the urine, including two carcinogens, TCEP, and chlorinated “Tris” or TDCIPP. This was the first time TCEP was detected in Americans.

“People with the highest metabolite levels of two carcinogenic flame retardants also had the highest levels in their house dust.” The fact that levels in dust correspond with urine levels indicates that these harmful chemicals are migrating out of products in our homes and into our bodies.

Many factors contribute to the prevalence and increasing rates of osteoporosis and obesity around the world. Poor diet and inactivity contribute to obesity; aging populations will have lower bone density. But chemical exposures may also be contributors.

According to the CDC, overweight and obese people are at increased risk for developing heart disease, Type 2 diabetes, certain cancers, stroke and other serious conditions.

The American Academy of Orthopaedic Surgeons says osteoporosis affects more than 44 million Americans and contributes to 2 million bone fractures per year. In the US, the number of fractures due to osteoporosis may rise to over 3 million by the year 2025.

“One out of four people who have an osteoporotic hip fracture will need long-term nursing home care [and] have a 24% increased risk of dying within one year following the fracture.” That’s serious business for older people. But what about children?

Firemaster 550 is found at higher levels in toddlers than adults. Studies suggest that dust ingestion may be the major route of exposure to TPP in children. But how many sources of phosphate exposure children are having? at what levels? what are the health effects of prenatal and childhood exposures?

I started this blog noting “no studies have been done examining the effects of phosphate flame retardants on children”. Now that researchers are developing methods of testing for and measuring this group of chemicals more studies must be done to fill in the information gaps.

FM550 hasn’t provided a fire safety benefit in furniture foam and is no longer needed due to updating of furniture flammability standards. Given what we do, and more importantly, don’t know about PFRs, will FM550 continue to be used in furniture foam?

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