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Selected tag(s): Carbon nanotubes

EPA Nano Authority under TSCA, Part 2: “New” Isn’t Necessarily All That Better

By / Published: May 27, 2008

Richard Denison, Ph.D., is a Senior Scientist.

[Links to posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5]

In my last post, I decried EPA’s shortsighted decision to declare nano forms of chemicals listed on the Toxic Substances Control Act (TSCA) Inventory to be “existing” rather than “new” chemicals.  But I noted that EPA did not rule that all nanomaterials are existing chemicals.  EPA says it will consider buckyballs, carbon nanotubes, or anything else that has no counterpart – a substance with the same chemical structure – already on the TSCA Inventory to be “new.”  So can we rest assured that, at least for these nanomaterials, EPA has sufficient authority under TSCA to effectively identify and address their potential risks?  Would it were so.  Read More »

Posted in Health policy, Nanotechnology, Regulation / Also tagged , | Read 1 Response

Are Multi-Walled Carbon Nanotubes More Like Asbestos Than We Thought? Part II

By John Balbus / Published: May 20, 2008

John Balbus, M.D., M.P.H., is Chief Health Scientist.

A new study published today in Nature Nanotechnology finds that multi-walled carbon nanotubes (MWCNTs) cause inflammatory changes in mice that closely resemble those caused by asbestos.  This is the second study in a few months to make this finding.  (I posted on the first, Takagi et al., a few weeks ago.)  So is the case closed on multi-walled carbon nanotubes?  Or is too early to draw conclusions? Read More »

Posted in Emerging science, Health science, Nanotechnology / Also tagged | Read 4 Responses

EPA Nano Authority under TSCA, Part 1: It All Depends on What “New” Means

By / Published: April 22, 2008

Richard Denison, Ph.D., is a Senior Scientist.

[Links to posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5]

In this and my next two posts, I want to explore the question of whether EPA has sufficient authority under the Toxic Substances Control Act (TSCA) to effectively oversee nanotechnology.  EPA (as well as the White House) maintains that the agency has ample statutory authority to do what’s needed to identify and address any potential risks nanomaterials may pose to consumers, the general public and the environment.  I beg to differ.  Read More »

Posted in Health policy, Nanotechnology, Regulation / Also tagged | Read 1 Response

Are Multi-Walled Carbon Nanotubes More Like Asbestos Than We Thought?

By John Balbus / Published: April 17, 2008

John Balbus, M.D., M.P.H., is Chief Health Scientist.

We and many others have made analogies between nanoparticles and asbestos.  The purpose of the analogy has generally been to emphasize the long latency that can occur between exposure to toxic materials and the development and subsequent recognition of disease arising from that exposure.  And, of course, the enormous legal and financial burden of failing to adequately consider risks before allowing widespread exposure.  But a new study suggests that the analogy may be even stronger than we thought:  It may extend to the capacity to cause mesothelioma, the rare form of cancer associated with exposure to asbestos. Read More »

Posted in Emerging science, Health science, Nanotechnology / Also tagged , | Read 3 Responses

My CNT is Better than Your CNT… Or At Least It’s Different

By / Published: April 7, 2008

Cal Baier-Anderson, Ph.D., is a Health Scientist.

After posting to this blog the other day, I came across a brand new study characterizing the heterogeneity of carbon nanotubes.  The authors of this study looked at 11 single-wall carbon nanotubes (SWCNTs) from 10 different suppliers and found that SWCNT composition varies dramatically depending on synthesis method, feedstock, purification steps, and other factors.  Read More »

Posted in Health science, Nanotechnology / Tagged | Read 1 Response

Getting to General Principles: Are We Making Progress?

By / Published: April 2, 2008

Cal Baier-Anderson, Ph.D., is a Health Scientist.

With conventional chemicals, experience has allowed us to articulate general criteria based on chemical properties that identify chemicals of greatest concern.  For example, persistent and bioaccumulative chemicals are assigned a high priority, whereas chemicals that quickly degrade and don’t build up in blood or tissue are, as a rule, likely to be of lower priority.

Concerns about nanomaterials arise from observations that properties that emerge or are greatly enhanced at the nanoscale can alter behavior, including biological activity.  These properties make such materials different from conventional forms of the same chemicals.  But can a general principle that nanomaterials pose a greater concern than their conventional counterparts be supported?  Read More »

Posted in Nanotechnology / Also tagged | Read 2 Responses