For your delectation and delight, desultory dicta on the law of delicts.

Is Your Daubert Motion Racist?

July 17th, 2020

In this week’s New York Magazine, Jonathan Chait points out there is now a vibrant anti-racism consulting industry that exists to help white (or White?) people to recognize the extent to which their race has enabled their success, in the face of systematic inequalities that burden people of color. Chait acknowledges that some of what this industry does is salutary and timely, but he also notes that there are disturbing elements in this industry’s messaging, which is nothing short of an attack on individualism as racist myth that ignores that individuals are subsumed completely into their respective racial group. Chait argues that many of the West’s most cherished values – individualism, due process, free speech and inquiry, and the rule of law – are imperiled by so-called “radical progressivism” and “identity politics.”[1]

It is hard to fathom how anti-racism can collapse all identity into racial categories, even if some inarticulate progressives say so. Chait’s claim, however, seems to be supported by the Smithsonian National Museum of African American History & Culture, and its webpages on “Talking about Race,” which provides an extended analysis of “whiteness,” “white privilege,” and the like.

On May 31, 2020, the Museum’s website published a graphic that presented its view of the “Aspects & Assumptions of Whiteness and White Culture in the United States,” which made many startling claims about what is “white,” and by implication, what is “non-white.” [The chart is set out below.] I will leave it to the sociologists, psychologists, and anthropologists to parse the discussion of “white-dominant culture,” and white “racial identity,” provided in the Museum’s webpages. In my view, the characterizations of “whiteness” were overtly racist and insulting to all races and ethnicities. As Chait points out, with an abundance of irony, Donald Trump would seem to be the epitome of non-white, by his disavowal of the Museum’s identification of white culture’s insistence that “hard work is the key to success.”

The aspect of the graphic summary of whiteness, which I found most curious, most racist, and most insulting to people of all colors and ethnicities, is the chart’s assertion that white culture places “Emphasis on the Scientific Method,” with its valuation of “[o]bjective, rational linear thinking; “[c]ause and effect relationships”; and “[q]uantitative emphasis.” The implication is that non-whites do not emphasize or care about the scientific method. So scientific method, with its concern over validity of inference, and ruling out random and systematic errors, is just white privilege, and a microaggression against non-white people.

Really? Can the Smithsonian National Museum of African American History & Culture really mean that scientific punctilio is just another manifestation of racism and cultural imperialism. Chait seems to think so, quoting Glenn Singleton, president of Courageous Conversation, a racial-sensitivity training firm, who asserts that valuing “written communication over other forms” is “a hallmark of whiteness,” as is “scientific, linear thinking. Cause and effect.”

The Museum has apparently removed the graphic from its website, in response to a blitz of criticism from right-wing media and pundits.[2]  According to the Washington Post, the graphic has its origins in a 1978 book on White Awareness.[3] In response to the criticism, museum director Spencer Crew apologized and removed the graphic, agreeing that “it did not contribute to the discussion as planned.”[4]

The removal of the graphic is not really the point. Many people will now simply be bitter that they cannot publicly display their racist tropes. More important yet, many people will continue to believe that causal, rational, linear thinking is white, exclusionary, and even racist. Something to remember when you make your next Rule 702 motion.

[1]  Jonathan Chait, “Is the Anti-Racism Training Industry Just Peddling White Supremacy?” New York Magazine (July 16, 2020).

[2]  Laura Gesualdi-Gilmore “‘DEEPLY INSULTING’ African American museum accused of ‘racism’ over whiteness chart linking hard work and nuclear family to white culture,” The Sun (Jul 16 2020); “DC museum criticized for saying ‘delayed gratification’ and ‘decision-making’ are aspects of ‘whiteness’,” Fox News (July 16, 2020) (noting that the National Museum of African American History and Culture received a tremendous outcry after equating the nuclear family and self-reliance to whiteness); Sam Dorman, “African-American museum removes controversial chart linking ‘whiteness’ to self-reliance, decision-making The chart didn’t contribute to the ‘productive conversation’ they wanted to see,” Fox News (July 16, 2020); Mairead McArdle, “African American History Museum Publishes Graphic Linking ‘Rational Linear Thinking,’ ‘Nuclear Family’ to White Culture,” Nat’l Rev. (July 15, 2020).

[3]  Judy H. Katz, White Awareness: Handbook for Anti-Racism Training (1978).

[4]  Peggy McGlone, “African American Museum site removes ‘whiteness’ chart after criticism from Trump Jr. and conservative media,” Wash. Post (July 17, 2020).

Sharpiegate – Trump’s Assault on Scientific Expertise

July 10th, 2020

Trump lies so often, so irresponsibly, so ruthlessly, that the American people have become numb to the assault on truth. Remarkably, Trump’s lies are frequently casual, random, non-ideological, and wanton. When the lies are about scientifically verifiable processes and outcomes, the lies are particularly reprehensible because they further dumb the American people’s shaky aptitude for scientific discourse.

Take Trump’s lie last September that Hurricane Dorian would hit Alabama much harder than had been anticipated. Thousands of lies later, perhaps only a few may remember the doctored weather map, on which a falsified projection had been drawn with a sharpie pen, to suggest that the hurricane was moving towards southeastern Alabama. A few days later, the National Oceanic and Atmospheric Administration (NOAA) issued a statement that purported to support Trump’s bogus forecast.[1]

Now, almost a year later, the Inspector General for the Commerce Department, Peggy Gustafson, has issued a report that lambasts the White House (Trump and cronies) for pressuring the NOAA into issuing its unscientific, unsupportable statement.[2] The Inspector General found that the NOAA had politicized a straightforward scientific assessment, backed the Trumpian forecast, criticized the agency’s own scientists, and eroded public trust in the agency, by succumbing to pressure from the White House.

Of course, 40 percent of the United States’ electorate will not care, as long as they have their theocracy. Ms. Gustafson’s days are numbered, even as the End Times draw nigh for Trump. You may not need a weatherman to know which way the blows, but you do if you want to know which way the wind will blow.

Remember, that 40 percent could be on your jury. And there may be another 40% that blows the other way. Sharpiegate is a poignant reminder that abuse of science occurs in all three branches of government.

[1]  Andrew Freedman & Jason Samenow, “Investigation rebukes Commerce Department for siding with Trump over forecasters during Hurricane Dorian: Report confirms Commerce officials responded to orders from the White House,” Wash. Post (July 9, 2020).

[2]  Gustafson, Evaluation of NOAA’s September 6, 2019, Statement about Hurricane Dorian Forecasts (June 26, 2019).

The Plague and Quackery Right & Left

June 19th, 2020

Earlier this week, the U.S. Food and Drug Administration announced the revocation of its emergency use authorization for chloroquine and hydroxychlorine (HCQ).[1] The FDA had originally granted the emergency use authorization for HCQ, on March 28, 2020, but its continued review found that the drug was “unlikely to be effective at treating COVID-19” and the potential risks of HCQ use outweigh any potential benefits. The Agency action was in line with the evolving standard of care for COVID-19, and the available evidence from clinical trials. The medical community applauded, but the Trump Administration, which had been stockpiling HCQ, labeled the revocation as “a Deep State blindside by bureaucrats who hate the administration they work for more than they’re concerned about saving American lives.”[2]

For weeks, Donald John Trump, the short-fingered vulgarian, the Orange Man, the loser of the 2016 popular vote, the Narcissist-in-Chief of the United States, has been hawking the anti-malarial medication HCQ as a potential therapy for COVID-19. Trump’s first public endorsement of HCQ came on March 19, 2020, after its use had been thoroughly scientifically vetted for a few days by talking heads at Fox News.[3] Foxy Laura Ingraham interviewed lawyer Gregory Rigano, author of one of the HCQ papers, who announced to Laura that HCQ can “just get rid of [the virus] completely.”

On April 24, the FDA “issued an alert warning doctors against prescribing the drug for COVID-19 outside of hospitals and research settings because of the risks of serious side effects and death.” Although Trump may be stupid, he is strong and resolute. On May 18, 2020, the nominal President of the United States, announced that he is taking hydroxychloroquine (HCQ), an anti-malaria medication that he had been hyping for months as a potential treatment for COVID-19.[4] When pressed for why he was taking HCQ for prophylaxis, Trump explained his basis:

“Here we go. Are you ready? Here’s my evidence. I get a lot of positive calls about it.”

Although Drs. Anthony Fauci and Deborah Birx have clearly explained that there was insufficient evidence to conclude that HCQ was efficacious in treating COVID-19, and no evidence that HCQ was preventative, Agent Orange followed the playbook he inherited early in life from Roy Cohen: never apologize, never acknowledge you have been wrong, just change the conversation.[5]

Trump’s embrace of HCQ was peculiar in the face of his usual disregard for prophylactics. Of course, Agent Orange’s advocacy for HCQ arose in the context of another lie: virus denial. Trump acolyte Rush Limbaugh has asseverated that the viral agent behind COVID-19 is

“‘the common cold’ that’s being ‘weaponized’ against Trump.”

* * * * * * * * * * * * * * * * * * * * * * * *

“Now, I want to tell you the truth about the coronavirus. … Yeah, I’m dead right on this. The coronavirus is the common cold, folks.”[6]

In the United Kingdom, men who have contributed greatly to an activity and who have gained national and international respect are knighted by the Queen and become Knight Commanders of the Most Excellent Order of the British Empire. In the United States, the President awards the National Medal of Freedom. During this year’s state-of-the-union address, Trump, while ignoring warnings of the COVID-19 pandemic, awarded the Medal to master trash-talker Rush Limbaugh. Remarkably, the toxicity of Agent Orange is manifested in support for both virus denial and for a bogus therapy.

Evidence is never really necessary for opinion, as Trump has taught us. For his endorsement of HCQ, Trump has, however, the opinion of “experts,” at the Association of American Physicians & Surgeons (AAPS). The AAPS has been stridently championing the cause of HCQ with what can be called only scientific propaganda,[7] including the debunked study by Didier Raoult, which has drawn a statement of concern from the scientific group, International Society of Antimicrobial Chemotherapy (ISAC), which publishes the journal in which Raoult’s results appeared.[8] The AAPS also relied upon claims made Vladimir Zelenko about 1,554 patients, for which he had “published no data, described no study design, and reported no analysis.” And since no quackfest would be complete without hard evidence from Mehmet Cengiz Öz, commonly known as Dr. Oz, the AAPS has dutifully reported that Oz had two patients to whom he gave HCQ, and both survived.

The HCQ issue is not the AAPS’s first quack rodeo. Those who follow the organization will sense déjà vu.[9] A sampler of AAPS’ scientific contributions to public policy debates include:

Abortion and Breast Cancer. The AAPS, on shoddy evidence, jumped on the issue whether abortion causes breast cancer, in 2002, to equate abortion for a teenager as “child abuse,” because the procedure will cause a “30% risk of breast cancer in her lifetime.” The AAPS ignored better and fairly definitive evidence of no association.

Vaccination and Austim. The AAPS has unrepentantly engaged in anti-vaccination propaganda. While acknowledging the scientific consensus against the claim that vaccines cause autism, the group raised hyperbolic doubts and threw itself in with conspiracy theorists to oppose mandatory vaccination.[10] When a measles outbreak occurred in Florida, in 2015, the AAPS issued a news release that “linked” autism with the measles vaccine.

HIV and AIDS. Despite the careful and well-documented conclusion of the National Academy of Science, in 1988, that AIDS was caused by a virus, HIV, the AAPS remains unconvinced. As recently as 2015, the AAPS, through its Executive Director Jane Orient, has questioned the connection and the standard-of-care treatment for HIV infection.

Barak Obama and Hypnotic Induction. In 2008, the AAPS website published an article that condemned Obama’s use of covert hypnotic techniques, which the group traced to Milton H. Erickson’s so-called neurolinguistic programming. The AAPS cited to “An Examination of Obama’s Use of Hidden Hypnosis Techniques in His Speeches,” a 67-page, unpublished, unsigned manuscript, on a right-wing conspiracy website, which no longer seems to have this masterpiece. Fortunately, the “proof” is still available online.

If the AAPS appears to trade in all manner of scientific quackery with a distinctive Republican flavor, then you will not be surprised that its General Counsel is Andrew Schafly, son of the late Phyllis Schafly (1924-2016). Mom was the Grand Dame of the know-nothing Republican party after she helped kill off the Nelson Rockefeller wing of the G.O.P.

Under Andrew Schafly’s deft legal guidance, the AAPS sued the FDA,[11] on June 2, 2020 to end “its arbitrary interference with the use of hydroxychloroquine.”[12] Schafly proudly cited his support for HCQ, which President Trump and other world leaders have taken as a prophylaxis against COVID-19.

The June 2nd AAPS Press Release generously cites and quotes Andrew Schafly’s pronouncements that

“that if everyone [sic] was allowed to take hydroxychloroquine, there would be no need for any social distancing or restrictions on mass gatherings”


“Entrenched, politically biased officials at the FDA should not be allowed to interfere with Americans’ right to access medication donated to the federal government for public use. … By preventing Americans’ use of HCQ as a prophylaxis, the FDA is infringing on First Amendment rights to attend religious services or participate in political events such as political conventions, town halls, and rallies in an important election year.”[13]

The litigious Mr. Schafly claims that “[t]here is no legal or factual basis for the FDA to limit use of HCQ,” and that the agency’s restrictions on HCQ are indefensible. The FDA was unmoved and proceeded yesterday to remove its emergency use authorization for HCQ.

We really did not need a plague to learn that Don Trumpolino and his acolytes were liars and buffoons. Still, the plague was, like so many other events, a great Rorschach epistemic test about care for the truth. In the 1980s, I thought that the toxicity of Agent Orange was exaggerated, but now that the theocons have dropped this weaponized Russian Agent Orange on the White House, I see that I was wrong. The entire country is suffering post-trumpatic stress disorder. We have all stepped in Tweety Turd. But why does truth have to be the first casualty?

The plague has, however, revealed the tenuous connection many United States citizens have with the truth. For anyone who has toiled in the American litigation stables, fragility of respect for truth is a given. Kurt Andersen’s book Fantasyland shows how exceptional Americans are when it comes to cults, conspiracies, fanaticism, fantasies, superstitions, and the like.[14] Andersen makes the point that more cults and new religions are spawned in the USA than in Europe or any else. No surprise then, when Andrew Wakefield was run out of the U.K., he found a warm embrace in the USA from RFK Jr. and Jenny McCarthy. Maybe the truth, small t, never had a chance in the United States, the land of Truth, big T, with its conspiracies and unbounded credulity.

Is American exceptionalism just another instance of the American public’s credulity? I would like to believe that our exceptionalism is real and tied to our great principles and the implicit promise that someday the promise of those principles will be kept.[15] Today, American exceptionalism looks more like an excuse to avoid our own Vergangenheitsbewältigung over slavery and genocide. We have an entrenched minority who adore the Confederacy and its pantheon of losers, traitors, and racists.

Even so, there are traps of untruthfulness on the left, as we see in the New Woke Times’ reinventing history to make slavery into an abuse of capitalism, when in fact slavery was the ultimate alienation of human beings from their labor through force, feudalism, and religion. Apologists for Southern chattel slavery criticized Northern “free labor” capitalism, but woke scholarship finds this inconvenient. Today, facts seem disposable on the left as well, with much needed calls for racial justice and police reform, larded down with virtue signaling and hand-waving excuse mongering for looting and failure to insist that all people stop resisting arrest. These are tough times for the truth.

[1]  FDA Press Release, “Coronavirus (COVID-19) Update: FDA Revokes Emergency Use Authorization for Chloroquine and Hydroxychloroquine” (June 15, 2020); Molly Walker, “HCQ No Longer Approved Even a Little for COVID-19 – Study after study showed no benefit, and now the FDA has had enough,” MedPage Today (June 15, 2020).

[2]  Sheryl Gay Stolberg, “A Mad Scramble to Stock Millions of Malaria Pills, Likely for Nothing,” N.Y. Times (June 16, 2020) (quoting Trump’s Trade Advisor Peter Navarro). Curiously, the Administration has ignored the emerging potentially good news about the efficacy of dexamethasone in treating seriously ill COVID-19 patients, as shown in a randomized clinical trial, which is not yet peer reviewed and published. Benjamin Mueller & Roni Caryn Rabin, “Common Drug Reduces Coronavirus Deaths, Scientists Report,” N.Y. Times (June 16, 2020).

[3]  Philip Bump, “The rise and fall of Trump’s obsession with hydroxychloroquine – Forty days of promotion, hype – and eventual retreat,” Wash. Post (April 24, 2020).

[4]  “Remarks by President Trump in a Roundtable with Restaurant Executives and Industry Leaders” (May 18, 2020).

[5]   Andrew Solender, “All The Times Trump Has Promoted HydroxychloroquineForbes (May 22, 2020).

[6]   Allyson Chiu, “Rush Limbaugh on coronavirus: ‘The common cold’ that’s being ‘weaponized’ against Trump,” Wash. Post (Feb. 25, 2020); See alsoThe corona virus is the common cold”; “Rush Limbaugh: coronavirus a ‘common cold’ being ‘weaponised’ against Trump,” The Guardian (Feb. 25, 2020). See generally Anthony Bardon, “Science Denial,” chap. 2, in The Truth About Denial: Bias and Self-Deception in Science, Politics, and Religion (2019) (exploring the role of cognitive dissonance, motivated reasoning, and confirmation bias, in science denialism).

[7]   “Hydroxychloroquine Has about 90 Percent Chance of Helping COVID-19 Patients,” AAPS (April 28, 2020).

[8]   The ISAC reported that Raoult’s work “does not meet the Society’s expected standard,” and that the ISAC was concerned “regarding the content, the ethical approval of the trial and the process that this paper underwent.”

[9]  David Gorski, “The Association of American Physicians and Surgeons: Ideology trumps science-based medicine,” Science-Based Med. (June 23, 2008).

[10]   AAPS, “Statement on Federal Vaccine Mandates” (Feb. 26, 2019).

[11]   The AAPS complaint is available at its website:

[12]   “AAPS Sues the FDA to End Its Arbitrary Restrictions on Hydroxychloroquine,” AAPS (June 2, 2020).

[13]    Id.

[14]  Kurt Andersen, Fantasyland: How America Went Haywire – A 500-Year History (2017).

[15]  See, e.g., People v. Ruggles, 8 Johns. R. 290 (N.Y. 1811) (Kent, C.J.) (holding that common law of crime prohibited blasphemy but only for blasphemy against Chancellor Kent’s own religious superstitions).

ACGIH TLVs Lack Scientific Integrity & Transparency – The Mica NIC

June 2nd, 2020

The American Conference of Governmental Industrial Hygienists (ACGIH®) is a non-profit corporation established in 1938, to advance occupational and environmental health.  The corporation’s motto, included in its logo, hubristically announces:  “Defining the Science of Occupational and Environmental Health.”

Philosophers of science may demur from “the” in “the Science,” as well as from the intellectual arrogance in suggesting that this private organization has any such ability to commandeer the complex social nature of scientific knowledge. And yet, in the small area of setting permissible exposure limits to potential environmental or occupational toxic substances, the ACGIH is in the business of “defining” safety. Starting in 1941, the group started to review and recommend “exposure limits.” In 1956, the group coined (literally and figuratively) the term “threshold limit values” (TLVs®), and started to publish documentation for its recommended values.

From the beginning, the ACGIH has asserted that TLVs® are not standards; rather they are guidelines for use, with other information, in determining safe levels of workplace and environmental exposure. The ACGIH maintains that its TLVs are based upon published, peer-reviewed scientific studies in industrial hygiene, toxicology, occupational medicine, and epidemiology, without consideration for economic or technical feasibility.

Beginning in the 1980s, “the Lobby”[1] started to throw brushback pitches at the ACGIH to bully the organization out of positions that the Lobby thought were too comforting to manufacturing industry.[2]  The result was a dramatic shift in the ACGIH’s perspective. The bullying created a “white-hat” bias that operates as a one-way ratchet to push the ACGIH always to lower TLVs, regardless whether there was a scientific warrant for doing so. Efforts to curb ACGIH overreach by litigation have generally failed. The TLVs have becoming increasingly controversial and non-evidence-based.[3]

What follows is what a hypothetical stakeholder might submit in response to a recent ACGIH Notice of Intended change for its TLV for mica dust. Like other mineral dusts, mica when inhaled in large quantities over long time periods, causes a pneumoconiosis. Documenting a “reasonable safe” level requires studies with adequate quantification of exposure. I will leave the reader to decide whether the ACGIH has that evidence in hand, based upon the following.

[1]  F.D.K. Liddell, “Magic, Menace, Myth and Malice,” 41 Ann. Occup. Hyg. 3, 3 (1997); seeThe Lobby Lives – Lobbyists Attack IARC for Conducting Scientific Research” (Feb. 19, 2013).

[2]  Barry I. Castleman & Grace E. Ziem, “Corporate influence on threshold limit values,” 13 Am. J. Indus.  Med. 531 (1988); Grace Ziem & Barry I. Castleman, “Threshold limit values: historical perspectives and current practice,” 31 J. Occup. Med. 910 (1989); S.A. Roach & S.M. Rappaport, “But they are not thresholds:  a critical analysis of the documentation of Threshold Limit Values,” 17 Am. J. Indus. Med. 727 (1990).

[3]  Philip E. Karmel, “The Threshold Limit Values Controversy,” N.Y. L. J. (Jan. 3, 2008).


These comments are in response to the proposed change in the ACGIH® TLV® for Mica, as explained in the ACGIH “Mica: TLV® Chemical Substances Draft Documentation, Notice of Intended Change” (“NIC”).  For the reasons stated below, the change in the Mica TLV-TWA (time-weighted average) in the NIC is not warranted and the existing Mica TLV should not be changed.

The ACGIH® TLVs® are important non-governmental standards, largely because a number of government entities incorporate TLVs by reference into regulations and thus give TLVs the force of law.[4]  For example, some states and Canadian provinces simply adopt TLVs as state or provincial occupational exposures levels, and some states have established “maximum allowable ambient concentrations” or similar limits on “toxic air contaminants” based entirely or in part on TLVs.  The U.S. Mine Safety and Health Administration (MSHA) uses the 1973 ACGIH TLV for crystalline silica (quartz) as a legally enforceable permissible exposure level.[5]  The U.S. Occupational Health and Safety Administration (OSHA) Hazard Communication Standard requires that ACGIH TLVs be disclosed in required Safety Data Sheets.  The process by which the ACGIH develops TLVs is critically important, and furthermore, given the regulatory and legal significance of the ACGIH TLVs, the ACGIH has the burden to support proposed changes in TLVs by an adequate process, which includes transparency and evidence sufficient to support any proposed change.

The flaws in the ACGIH TLV setting process are well known and the subject of several publications, most recently in paper titled “142 ACGIH Threshold Limit Values® established from 2008-2018 lack consistency and transparency.”

The following specific comments address the ACGIH’s process disclosed in the ACGIH’s NIC in support of its proposed change for the TLV-TWA for mica, which illustrate the process problem — the ACGIH NIC for the proposed Mica TLV-TWA change does not support the change proposed by the ACGIH.   Again, the ACGIH TLVs have regulatory and legal significance; therefore, the ACGIH should not make TLV changes arbitrarily and capriciously.  Instead, the changes should be made pursuant to a transparent process, and the ACGIH should support the proposed changes with the weight of the available evidence, and the evidence in support of and the reasons for the proposed change should be publicly disclosed.  It has not done that in this case, and its own NIC makes it clear that it has not:

  1. There is no evidence that “mica is an important cause of disabling occupational pneumoconiosis” as stated in the NIC. 

The NIC provides no citation or other supporting evidence for this conclusion; it merely states the conclusion as “fact” and a premise for the proposed change.[6] The NIC fails to estimate the number of workers currently potentially exposed to mica in the U.S. (or elsewhere), what industries these workers work in, what forms of mica these workers may be exposed to, what levels of respirable mica these workers may be exposed to, and to what extent pneumoconiosis caused by the inhalation of respirable mica exists.[7]

  1. The NIC proposes to materially lower the TLV for mica, but, other than noting that there are “nine different major species”, does not adequately address the mineralogical differences between the different species of mica, makes no attempt to assess the potential adverse health effects for the different species of mica, does not examine the “dose-response” data (as inadequate as it is) for the different species of mica, and so on. 

The “Chemical and Physical Properties” section of the NIC suggests the wide variety of materials that fall within the general term “mica”.  In spite of this, the ACGIH appears to have ignored differences and concluded that the TLV for “mica” as a general category of substances should be applicable to all forms of mica, with no support for this conclusion in the NIC.[8]

  1. The human studies (sic) cited in the NIC are inadequate to support a decision to change the mica TLV and do not support the mica TLV proposed.

The first cited study involved four employees in a muscovite milling plant, with an alleged exposure to respirable mica (as muscovite) dust between 1.86 and 5.77 mg/m3.

The second cited study involved a (one) South African man who worked in a mica milling factory.  As noted in the NIC, “[q]uantitative exposure data were not reported.”

The third cited study involved a (one) 65-year old who worked in the rubber industry for 40 years, where he was exposed to numerous dusts, including mica.  There was no exposure data reported.

The fourth study involved a (one) 62-year old woman allegedly exposed to “pure mica” for seven years; no quantitative exposure data were available.

The NIC cites the case of a worker who bagged mica flake for 36 years.  In this case, there were, apparently, two dust samples taken – one at the time of a medical exam of the worker at age 54, total dust of 0.2 mg/m3 — and one taken 17 years earlier – 0.7 mg/m3.  The bulk mica samples disclosed 7.1% to 8.4% silica (presumably, respirable crystalline silica as quartz).  The reference to the silica content of the “bulk samples” suggests that there was no analysis of the material collected in the two air samples taken.

The NIC cites the case of two British men who worked as “grinders of imported muscovite,” one starting in 1957. The “workplace dust concentrations were not quantified.”

The next paper cited in the NIC was from 1940 and involved employees who were exposed to the dust caused by “mica-scrap” grinding.  There was actually an attempt to quantify mica exposures (the data from before 1940), but it was done by particle count.  The NIC notes that the available information regarding mica health effects may be “limited by potential uncertainty converting from mppcf (million particles per cubic foot) to mg/m3 (which might not apply to all dust exposure scenarios).”  The difficulties associated with converting from mppcf to mg/m3 are well known in the cases of minerals far more extensively studied than mica (e.g., crystalline silica as quartz).  In addition to the conversion factor issue, there are other concerns raised by relying upon a paper published in 1940 to support a TLV today, such as, the quality of the sampling, the quality of the chest x-rays, and issues with the classification of the chest x-rays.  With that said, the NIC noted that “[n]one of the workers exposed at less than 10 mppcf (1.8 mg/m3), irrespective of employment duration, developed pneumoconiosis.”

The remaining studies cited in the NIC are similar.  But, to close this section of the comments, I will refer to the last study, a study of 71 South African workers employed in mica milling.  Twelve personal and static samples were taken during the course of the study.  The results of the personal samples indicated a range of respirable dust (or was it mica?) between 0.4 to 1.68 mg/m3.  The radiologic examination disclosed that 19 of the 71 workers had changes consistent with one or more of asbestos, silica and/or mica.  “The specific dust concentrations to which the individuals presenting with lung changes were exposed were not reported.”

The ACGIH is proposing a reduction in the mica TLV based on the studies as described in the NIC.  We submit that this is a process and transparency problem – there is simply no way to conclude that a reduction in the mica TLV is warranted based on the Human Studies (the “evidence”) cited in the NIC.  In most cases, the Human Studies are simply case reports involving one, two, or a few people, with no quantitative exposure data.  The studies with exposure data are inadequate, i.e., date from before 1940, and among other things measured exposure as mppcf, with one study literally including two samples.  Given the legal and regulatory significance of ACGIH TLVs, the evidence cited in support of the change in the mica TLV, and the reasonable conclusion that can be drawn from the evidence cited, should exceed some threshold and meet some burden.  The evidence in the NIC is grossly insufficient to support the proposed change.

  1. The NIC for mica does not disclose any evidence to support the proposed TLV of a TWA of 0.1 mg/m3

The comparison to OSHA’s notice of proposed rulemaking for occupational exposure to respirable crystalline silica (RCS) is instructive.  The supporting documentation sets forth a preliminary quantitative risk assessment outlining life-time risks for various disease end points associated with occupational exposure to RCS at various levels.  The preliminary quantitative risk assessment disclosed all of the underlying studies and methodology, sufficient to allow a reader to understand the basis for the risk assessment conclusions and agree or disagree with the conclusions.  Based on the risks (and other factors not considered by the ACGIH) set forth in the documentation, OSHA proposed a PEL (permissible exposure level) for RCS.

By contrast, the ACGIH simply contends for its proposed mica TLV: “Consequently, a TLV-TWA of 0.1 mg/m3 measured as respirable fraction (containing no asbestos and <1% crystalline silica) is recommended.”  The materials preceding “[c]consequently”, which in normal reading would be expected to support the conclusion following, are not a risk assessment or anything similar to one, and in no way even superficially support the conclusion – the recommendation – stated.[9]  Therefore, the ACGIH proposed a TLV-TWA of 0.1. The NIC materials do not support a TLV of 0.1 mg/m3, any more than they support a TLV of 0.0001 or 10.  It cannot be stated too emphatically that the NIC is devoid of any evidence to support any TLV, including the recommended TLV-TWA of 0.1 mg/m3.

Of course, the ACGIH TLV process is not a federal rulemaking.  And readers should be aware of the ACGIH Position Statement regarding TLVs (“TLVs … are not quantitative levels of risk at different exposure levels…”). But the same Position Statement notes that “TLVs®…represent conditions under which ACGIH® believes that nearly all workers may be repeatedly exposed without adverse health effects.”  So, presumably, the ACGIH concluded that its proposed mica TLV was that level, and yet there is simply no evidence in the NIC to support that conclusion.  Given the regulatory and legal significance of TLVs, the process of establishing TLVs should have some basis in science and evidence.


ACGIH® TLV/BEI® Position Statement, available at:

ACGIH® TLV/BEI® Policy Statement, available at:

30 C.F.R. § 56.5001 (MSHA exposure to airborne contaminants)

29 C.F.R. § 1910.1200 (OSHA Hazard Communications)

D. Davies & R. Cotton, “Mica pneumoconiosis,” 40 Br. J. Indus. Med. 22 (1983)

Subhabrata Moitra, “Mica pneumoconiosis: a neglected occupational lung disease – letter,” 6 The Lancet Respir. Med. e39 (2018), available at:

Notice of Proposed Rule Making (NPRM) for Occupational Exposure to Respirable Crystalline Silica, 56 Fed. Reg. 56273 (Sept. 12, 2013)

Knut R. Skulburg, “Mica pneumoconiosis – a literature review,” 11 Scand. J. Work & Envt’l Health 65 (1985)

Carl J. Smith & Thomas A. Perfetti, “142 ACGIH Threshold Limit Values® (TLV®s) established from 2008-2018 lack consistency and transparency,” 3 Toxicol. Research & Application 1 (2019)

[4] ACGIH states that TLVs are not intended to be legal standards, but the ACGIH recognizes the broad use of TLVs and should reasonably anticipate that TLVs will be used in ways beyond the scope of the legal disclaimers that the ACGIH publishes.

[5] 30 C.F.R. 56.5001

[6] The problems cited by Moitra — illegally operated mica mines exploiting vulnerable populations to work without protections in India and some African countries — speak to the need to eliminate illegal mining and protect vulnerable populations from exploitation, not the adequacy or inadequacy of any TLV.

[7] By comparison, see the OSHA documentation for the NPRM for Occupational Exposure to Respirable Crystalline Silica published September 12, 2013.  The citation to the 1985 Skulberg article (in “Major Sources of Exposure”) is inadequate on its face in 2020; the article summarizes world mica use from 1905-1981, and provides no information regarding use post-1981.  Likewise, the citation to the “Campaign for Safe Cosmetics” does not provide information on occupational exposure.

[8] The case of crystalline silica again provides a useful contrast.  There is no ACGIH TLV for “crystalline silica,” which as a general term includes many polymorphs.

[9] Actually, the materials that precede “consequently” explicitly refute the conclusion stated by the ACGIH (the TLV-TWA of 0.1 mg/m3) — “the published literature has established an association between mica exposure and pneumoconiosis typically at concentrations in the range of 1-6 mg/m3,”  and “no cases were observed among workers exposed to mica dusts at concentrations of 1.8 mg/m3 or less….”