National Academy of Science member dead from chemical suicide

This is awful, sad, but what else does it tell us?

California hotel evacuated after chemical suicide.

A historic San Francisco Bay Area hotel and social club has been evacuated after a resident used a toxic chemical to commit suicide in her room.

Police spokesman Ethell Wilson says the 80-year-old woman used sodium azide to kill herself Tuesday in her apartment on the third floor of the landmark Berkeley City Club.

She left a warning note.

In an update to that story, more was discovered about her identity.

Sydney Kustu was a professor emerita in plant and microbial biology at University of California’s College of Natural Resources and a member of the prestigious National Academy of Sciences. She lived in an apartment there. It was her 71st birthday.

In the fall of 2009, she told Breakthrough magazine, a publication of the College of Natural Resources, that science sustained and gratified her.

“I do science because at one time it was forbidden fruit,” Kustu told the magazine. “When I was a child, men had professions; women were assistants. As a young woman I developed a passion for understanding how cells replicate themselves, how they integrate their parts into a self-reproducing whole.”

The CDC describes sodium azide as a white solid that turns into a toxic gas (hydrazoic acid) when mixed with water or acid (H+) It is used in auto airbags and airplane escape chutes since it creates the gas so quickly. It is not known to be toxic from that use.

It affect the cardivascular system. In fatal doses, the person suffers rapid loss of consciousness, possibly coma with hyporeflexia and metabolic acidosis. [Source]

Honestly, when I heard this story, I wondered if she had medical issues and if there weren’t some easier way for people to take their own lives without endangering others if that’s their decision. This was a way she knew would work. There is no mention of where she obtained the chemical. Very sad.

It’s unclear if they can do an autopsy because of the exposure. Suicides from it are rare. Death usually occurs rapidly.

Addition: I was very moved by this story. After I posted it, I received comments such as: “she should have known better”, “why would someone educated do this”, both of which I found discordant. I also heard from several who noted that this situation was really NOT hazardous to others and she never meant to hurt anyone. I would believe that is true. I agree she must have been in deep despair. The story touched me because I respect people’s decisions to take their own lives. As noted in the comments, she lived an impressively full life and was a well-respected contributor to society. I feel conflicted leaving this story up because it seems so private but I can’t help but feel I learned so much from it about chemistry and people. I could not help but be fascinated as well as disturbed. I wish I knew more. I apologize if the original wording came off harsh. I meant no disrespect towards Dr. Kustu. Rest in peace, professor.

Sydney Kustu, Professor emerita of Univ of CA

Sydney Kustu, Professor emerita of Univ of CA

In 2009, six Harvard Medical School scientists were sickened after drinking coffee from a communal coffee machine that was laced with the chemical.

More (Journal papers are paywalled):

Suicidal sodium azide intoxication: An analytical challenge based on a rare case.

Suicidal sodium azide ingestion.

  9 comments for “National Academy of Science member dead from chemical suicide

  1. March 20, 2014 at 3:13 AM

    Sodium azide is ubiquitous in molecular biology labs, because it blocks oxidative phosphorylation via the electron transport chain and therefore very rapidly kills ATP-dependent processes. It is used for many purposes — most commonly for preventing microbes from contaminating solutions or for preserving the condition of proteins and their post-translational modifications when cells are lysed for biochemical analyses. It was almost certainly on the shelf in her lab.

    It seems very doubtful to me that she actually created much danger for others intentionally or otherwise. First of all, she almost certainly knew more than any average person about how sodium azide works and must have read about the lethal dose to be sure that she used enough for herself. She’s plainly too intelligent to go about suicide haphazardly and risk surviving. It only took me a moment to learn that as little as 0.7 grams can be lethal when swallowed ( For comparison, a packet of sweetener is typically 1 g. Furthermore, if she intended to harm others, it really would have been trivial for her to actively poison others with it, as the 2009 Harvard case shows. To illustrate the point, the chemical supply company Sigma-Aldrich sells 1 kg of sodium azide — for just $296.50 ( That’s the equivalent of over 1400 lethal doses for under 22 cents each. Kind of scary, and fortunately the CDC has detailed protocols for dealing with azide dispersal emergencies (

    While it’s very sad this happened and undoubtedly people will miss her, she seems to have lived a very long and rich life, and she accomplished a lot. I don’t feel like I’m in any position to judge her for making such a choice at 71 years old.

  2. Rider
    March 20, 2014 at 9:09 AM

    And thus is born a conspiracy theory based on nothing.

    Educated people never commit suicide.

  3. Julia
    March 20, 2014 at 11:03 AM

    Doctors in CA won’t help someone take their own life, even when they’re already dying. Theyre left waiting to die naturally, suffering for years, or they can take matters into their own hands.

  4. J
    March 20, 2014 at 11:45 AM

    There’s a curious age discrepancy between the first report and the update. Why did police think she was 80 when she had just turned 71? Also, to commit suicide on your birthday is another interesting point. I find it poetic in a way, but I’m left wondering what brought the decision on in the first place.

  5. March 20, 2014 at 12:38 PM

    Rider: I removed the comment this responded to. It was in appropriate. – editor

  6. Count Otto Black
    March 20, 2014 at 4:09 PM

    Having suffered from clinical depression myself, I can sympathize with a woman whose despair brought her to such a point that she could see no way out but death. I also feel that it’s unfair to draw attention to the apparently minimal risk she caused to others. I’m no chemist, but obviously this stuff can’t be horrendously toxic or they wouldn’t use it in air-bags, and it seems that several commenters who know their chemistry better than me, you, or the popular press agree on that point.

    How many people every year kill themselves by filling a room with highly inflammable gas? Once in a while it explodes and other people are killed, yet I’ve never read a news item which drew attention to what a selfish moron the recently-deceased X must have been to commit suicide in such an inconsiderate way, even on the very rare occasions when the gas did actually explode. Because, talking of inconsiderate, how would that make the deceased’s relatives feel? I suppose the press are milking this story because it involves someone borderline famous and the method was unusual, but it still seems petty to emphasize this point, and I don’t think this blog should be repeating the story in such a way as to echo the unfortunate way the press handled it.

    An issue which is perhaps more worthy of being touched on, if you’re trying to find something constructive to say at such a time, is the quote in which Professor Kutzu says that science “sustained and gratified her”. This odd choice of words suggests that without an abstract, impersonal thing called “science”, this professionally successful woman who lived by herself in a hotel would have nothing to live for. And she was saying things like that back in 2009, four and a half years before, all alone on her birthday, she killed herself.

    It sounds as though she was lonely for a very long time before she finally succumbed to utter despair. She wasn’t a mad reclusive shut-in; she had a full-time job involving constant interaction with lots of exceptionally intelligent people. Yet apparently her deep emotional problems weren’t noticed by any of them until it was too late. Maybe that’s something we should all think about?

    PS – That odd typo in the original article brings to mind the cult movie “Harold And Maud”, in which one of the title characters is a retired but apparently brilliant chemist who for existential reasons unexpectedly commits suicide on her 80th birthday. It wouldn’t be the first time a reporter couldn’t be bothered to distinguish between the actual facts and some half-remembered work of fiction.

  7. Chris
    March 20, 2014 at 4:31 PM

    I knew Sydney and was very sad to read this news. I agree with Nate, I highly doubt she endangered anyone. I used to use sodium azide on a daily basis to keep chromatography columns clean, and had 3M solutions of it sitting on my lab bench for years at a time. The news reports say it forms a gas, but when mixed with water it simply forms a solution that she could easily have swallowed. Common lab chemicals are often reported in a hyperbolic fashion in news articles. She was a great person, she did live a full life, and she imparted great things to those around her. Although I was shocked at first, in hindsight it sort of made sense to me because she was such a self-determined person that I could easily see her ending her own life on her own terms. Leaving a note, a sort of MSDS (Materials Safety Data Sheet), also sound like her (i.e. I took a chemical, don’t get it on your hands).

  8. March 20, 2014 at 4:37 PM

    Thanks for sharing this. I figured as much because that does make sense.

  9. Walter Turner
    March 20, 2014 at 5:29 PM

    Sodium azide in gas bags isn’t converted into hydrazoic acid, and that’s a good thing. Instead, it is brought to explosion, and the effective product is nitrogen gas, simple old N2 (I don’t know how to format a subscript here). Chemistry tells me that, but it doesn’t extend to telling me what happens to the co-product, a cloud of sodium metal. I could look it up, but it’s late here.

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