When it comes to 3D printing, the sky is the limit. As 3D printing technology continues to advance, applications can be as far reaching as airplane and automobile parts to medical devices and even anatomically correct, biocompatible models. Although 3D printing technology is developing at a rapid pace, the technology itself is not new. It emerged in the 1980s as a means of creating rapid prototypes. In recent years the applications for 3D printed models have evolved with the available hardware, software, and printable materials. Evolving technology, paired with the creative and innovative minds of scientists, engineers, and physicians, has been the launching pad for developments within 3D printing technology specific to healthcare. One way 3D printing technology is poised to create better patient outcomes is in creating an anatomically and patient-specific models to aid in surgery and medical procedures. With the capability to 3D print patient-specific models, more acc
It’s better to be safe than sorry. But the Environmental Protection Agency recently withdrew two proposed rules regulating chemicals that it had developed under authority of the Toxic Substances Control Act (TSCA) and submitted to the White House’s Office of Information in 2010 and 2011. Dr. Richard Deninson of the Environmental Defense Fund explains it further:
Faced presumably with the reality that OIRA [Office of Information and Regulatory Affairs] was never going to let EPA even propose the rules for public comment, EPA decided to withdraw them. The two proposed rules that were just withdrawn would have:
- Designated as ‘chemicals of concern’ three classes of chemicals for which evidence is more than sufficient to warrant such a designation: bisphenol A (BPA), a category of phthalates, and a category of polybrominated diphenyl ethers (PBDEs). By listing a chemical as ‘of concern,’ EPA may obtain, and provide to the public, more information about the chemical than it is typically able to access.
- Clarified, consistent with the language of TSCA, that health and safety studies on pre-market chemicals submitted to the agency cannot be claimed to be confidential business information (CBI), and that those studies along with the identity of the subject chemical should be made publicly available. This information is vital to ensuring the public’s and workers’ right to know about chemicals to which they may be exposed.
What do we know about these chemicals? Like many aromatic compounds, they are listed as endocrine disruptors, because they interfere with hormones in the human body.
BPA (Bisphenol A, a chemical used to produce polycarbonate plastics and epoxy resins) has been linked to obesity, cancer, asthma, heart disease, diabetes, and neurological disorders. It can affect thyroid, liver and reproductive function, and recently was tied to higher rates of miscarriage. The chemical industry tends to question study results. The biomedical research of BPA effects is on the rise. Fifty three epidemiological studies examining the effects of BPA on human health were published in 2012 alone.
As of July 2013, FDA regulations no longer authorize the use of BPA in infant formula packaging, following a similar regulation on baby bottles from last year, but the regulations clearly specify that the decision is based on abandonment and not on safety, meaning that manufacturers of baby bottles listened to the public and abandoned the use of BPA, while FDA followed. The FDA continues to study BPA to evaluate its safety, while we continue receiving our daily dose from BPA-containing polycarbonate bottles (PC, coded 7) and the inner coating of food and beverage cans. Keep in mind that BPA can be substituted by other toxic bisphenols.
Phthalates are the most commonly used plasticizers in the world, with more than 90% of them used to make polyvinyl chloride (PVC, coded 3) soft and flexible. Phthalates can be found in consumer products, including electrical cables, hoses, flooring, coated textiles, luggage, sports equipments, and footwear, as well as in medical devices such as tubing and blood bags. In addition, some phthalates are used in non-PVC applications such as coatings, rubber products, adhesives and sealants. High molecular weight phthalates (containing more than seven carbons in their backbone) have increased permanency and durability, are less leachable and thus are considered safer than low molecular weight phthalates.
The U.S. Congress banned six types of phthalates from children’s toys in 2008: DEHP (di(2-ethylhexyl) phthalate), DBP (di-n-butyl phthalate), BBP (butyl benzyl phthalate), DINP (diisononyl phthalate), DIDP (diisodecyl phthalate), and DnOP (di(n-octyl phthalate). The FDA recommended avoiding DBP and DEHP in pharmaceutical formulations in 2012. There have been studies linking phthalate exposure to cancer, obesity, endocrine disruption and liver toxicity, diabetes, low birth weight, and ADHD.
Plenty of information on BPA and phthalates is available. A PubMed biomedical literature search reveals more than 9,000 publications on BPA and more than 6,000 on phthalates, so we have a wealth of data from which to draw our own conclusions.
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