[Laforet]

On a related and lighter hearted note, back in the beginning of the 20th century the government of Hungary once mandated adding the pH indicator phenylphthalein to locally produced wine as a way to mark its origin for tax purposes. The compound is tasteless and clear at the acidic pH of wines, but would turn bright pink with some alkali added.

Sounds ideal right? However soon people started to complain that the wine gave them explosive diarrhea. Turns out that phenylphthalein is actually a potent laxative, just that nobody knew because it had never been given to such a large number of people in high doses. The wine were quickly withdrawn from the market and phenylphthalein remained a popular constipation medicine well into the 1980s before it was replaced by safer alternatives.

[hermitcrab]

I was at an all-boys boarding school in the 70s when a bottle of phenylphthalein went missing. They shut the whole school down until it reappeared (it was left on the windowsill of a teacher's house IIRC). No idea what the culprit was intending to do with it. Put it in the tea urn and try to make the whole school shit itself to death?

[hilbert42]

"...a bottle of phenylphthalein went missing"

Uh? What was the big deal? We had bottles of phenylphthalein in the school lab and no one cared a damn about it or whether any went missing because it was so commonly available and so cheap. And most of us had phenylphthalein at home in our medicine chests in name of Ford Pills. When TV ads told us to take it to 'keep fit and regular' it was just something one was used to: https://www.youtube.com/watch?v=uBPWt4OQ-RY

BTW, when I wanted an indicator at home for my chemistry set (in the days when they made 'real' sets with chemicals that actually did things) I just went to the medicine chest got the Ford Pills out and crushed them (they were a brownish color inside) but the additives usually weren't a problem, the indicator still worked fine.

[hermitcrab]

>What was the big deal?

I wasn't party to the decision making. But imagine the staff were a bit twitchy about what a malicious teenager could do with a whole bottle of the stuff. And what else they might do if they got away stealing the phenylphthalein.

[hilbert42]

When in the 70s?

I ask as there was a sudden shift in perception about the dangers of chemicals by the public sometime in the 1970s when worries were heightened (at least so in Australia where I was at the time but I think it occurred in many places). Perhaps it was this heightened concern that was responsible for the unnecessary worry over the stolen phenolphthalein.

What I've observed since my schooling in the 1960s is that worry about chemicals has definitely increased amongst the GP but unfortunately it has never been matched by a better understanding of chemistry. We often see this manifest in say overblown responses to incidents such as a spill of a relatively innocuous chemical, here both fear and perceived threat are not in keeping with actual reality. When all threats appear similar there's always the risk of not responding adequately to a situation that is actually very dangerous.

I'm glad my schooling was just before this change in thinking occurred because I had the chance to come in contact with materials that most school kids never see these days such as mercury, benzene, metallic potassium, sodium, lithium, white phosphorus, various —CN compounds, and we not only learned the equation for the black powder reaction but also we had to make the stuff and those who couldn't get it to explode failed the prac experiment. Also we had radioactive sources including metallic uranium of which discs were handed around the class to demonstrate its high density.

By today's standards that sounds like a dangerous free-for-all but it definitely was not. We were carefully and thoroughly instructed in the handling of chemicals including safety, storage, toxicity and having to recognize that certain types of chemicals were likely to be more toxic than others (even if we'd never encountered them previously then we should be especially wary of them due to the inherent characteristics of such compounds). Also much attention was paid to purity and why source was important (for instance, was the chemical lab or pharmaceutical grade).

On that last point we did an experiment where we even tasted certain reagents which I've not time to recount in detail here but it was the most important safety lesson about chemicals I was ever taught. Unfortunately, such is the fear of chemicals now that these days such experiments can never be done by school kids.

How is all this relevant to this story? It's simple really, even though I'd never learned about the toxic nature of lead chromate at school the training I had then would have made me acutely aware of its potential dangers even if I didn't know them specifically. Just the mention of lead chromate and food in the same sentence would have waved red flags even when I was a school kid! That it doesn't among some people nowadays is a real worry.

When it comes to toxicity some safety rules are dead simple—an organic compound containing a heavy metal is almost always toxic (and often very toxic). For instance, even if one had never come across them previously one could be almost certain that, say, lead acetate and methyl mercury would be toxic and you'd never want to encounter even small amounts in food. Also, much emphasis was placed on good lab practice and treating all chemicals as potentially dangerous especially those that were unknown or unlabeled.

I get really annoyed at stories like this turmeric-lead chromate one because whilst the world has become more aware of unwanted chemicals in our food and in the environment—which is a good thing—but, as mentioned, there hasn't been a corresponding improvement in understanding of the underlying chemistry by many of the public. This ignorance manifests as an overly strong fear of chemicals or just plain ignorance as in this turmeric story—or both. That all too many people are now frightened at the mere mention of the word 'chemical' is not helpful, it's very counterproductive and potentially dangerous.

That stories like this can still emerge in the 21st Century is worrying (same with your story about worries over stolen phenolphthalein) through the lack of basic chemistry knowledge is very disconcerting.

It seems to me that our approach to teaching chemistry to the GP is wrong in that we've been teaching it from the perspective that those taught will become chemists whereas it ought to be taught to provide a better general understanding of why the use of chemicals is essential in the modern world and that knowing how to both handle them safely and use them properly is of paramount importance.

An incident that happened to me some years back clearly illustrates what can happen when the heightened fear of chemicals amongst the GP combines with a profound lack of knowledge. During a meeting that I did not arrange and which I was not a central player about the banning of PVC wiring in houses an environmentalist said to me that "we [environments] will eventually get Element 17 banned altogether from everything."

Whenever I recount this odd encounter I substitute element's common/scientific name to Element 17 to highlight the sheer absurdity of such a notion, especially this element. Unfortunately, amongst some people zealotry and ignorance have combined to produce such utterances, but the trouble is that whilst this was an extreme case it nevertheless doesn't go unnoticed and ends up having a negative impact on the general discourse.

I was taught that chemistry is essential for the modern world to the function and not to be frightened of chemicals but rather to be mightily respectful of them and that to handle them properly requires some basic knowledge about chemistry.

We ought to be worried when more than a tiny minority can somehow deny the world—even food—is made of elements and chemicals and that all human-made chemicals are 'unnatural'. It's a sure indication that something isn't fully right with our education systems.

[hermitcrab]

>When in the 70s?

Lates 70s. Maybe 78 or 79.

The school wasn't overly obsessive about safety. They still us to regularly throw sodium into water to show what happened and that sort of thing. However it was a military school and the discipline was fierce. So perhaps they were more concerned about the theft than what was actually stolen.

I also despair about the public's general lack of education on scientific topics, to the point now where the word 'chemicals' is a synonym for unnatural or bad. Everything is made of chemicals and it always has been!

[jliptzin]

Interesting, when I was in school the preferred way to shut the school down was to call in a bomb threat from a pay phone

[hilbert42]

That's stupid and infantile and would get everyone offside. However there was one incident of notoriety that occurred about a year after I left school (so I take no credit for it nor would I've bothered) but the details weren't spared on me by someone who was still there.

We had a Kipp's generator (aka apparatus), https://en.wikipedia.org/wiki/Kipp%27s_apparatus, in the school chemistry lab (it was a well equipped school with separate physics chemistry and biology labs). Anyway, the Kipp's generator was mainly used for making H2S and was used in a properly equipped fume cupboard with a decent exhaust.

During the last day of term (muck-up day for final year students) some bright sparks decided to remove the generator from the lab and stick it in the airconditioning ducts with the view of stinking the whole school out.

Trouble was the science wasn't well thought out, they'd not calculated how much H2S would be required to produce an objectionable effect. From what I gather the odor was so minimal that the perpetrators who were looking for the odor could barely detect it.

BTW, everyone at school was taught [as part of the curriculum] the dangers of H2S and that after a certain threshold concentration it anesthetizes the nose so one thinks the concentration has fallen and that is why it's so dangerous.

[hermitcrab]

Remember that this was a boarding school. We didn't get to go home, so there was no benefit to getting everything shut down. Also they were quite into using peer pressure via collective punishment.

[marcosdumay]

Vanishing fake blood?

I'm way more curious about the reason for the harsh reaction from the school.

[kazinator]

I remember doing titrations with that stuff in an organic chemistry course.

It's phenOlphthalein!