“I was blinded by a school science experiment”

(Credit: Shutterstock)

(Credit: Shutterstock)

Via @adchempages, a personal story of the repercussions of being blinded by a school science experiment, by Meredith Plumb:

Throughout my childhood, I had 20:20 vision. But two weeks before my 12th birthday, in my first year of secondary school in Cheshire, my teacher asked me to conduct a science experiment, and gave me a pestle and mortar. I was told to measure three kinds of powder: black, orange and white. I did as I was told, but when I mixed them together, they exploded. I saw the flash, and then, what seemed like ages later, I heard the supersonic bang. Molten lava hit me in the face, but I felt no pain. …

I was taken to hospital, but the doctors didn’t know what to do with me. They hadn’t seen burns like that since the war, and never on a child. I was later flown to Barcelona and then Houston for surgery; between the ages of 13 and 16, I had 40 operations. As each operation came and went, my vision would come back, then fade again. Eventually, it faded completely and I had what was left of my eyes removed for cosmetic reasons.

The powders aren’t identified, but they may have been charcoal, sulfur, and potassium nitrate–aka gunpowder or black powder.

For those living in New England, note that the ACS Division of Chemical Health & Safety and the Lab Safety Institute are offering various discounts and scholarships for K-12 science teachers to attend safety workshops at the ACS meeting in Boston in August. Information is here (scroll down to see the workshop topics).

Author: Jyllian Kemsley

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  1. Why would they make the students do something like that? I’ve seen my friends being burnt [in my school days] but never to this extent. And that girl did as she was told too, hmm.

  2. Although it is tempting to attribute these chemicals to potassium nitrate, sulfur and charcoal, it was almost certainly not this mixture. The chances of black powder igniting from merely being ground in a mortar and pestle are extremely unlikely. It generally takes days of grinding to produce black powder that has a fast burn rate, and even the highest quality black powders would not produce a “supersonic bang” unless confined or in very large quantities (>500g). It is more likely the mixture contained a stronger oxidizer such as potassium dichromate (orange), potassium chlorate or perchlorate, which are known to form very sensitive mixtures with fuels and have the ability to detonate even when unconfined.

  3. This was not blackpowder. Ceramic balls are used industrially in “ball mills” where KNO3, S and C are ground between these balls for days to produce blackpowder. The friction sensitivity of blackpowder is exceedingly low and it can safely and easily be made in a mortar, although with an incredibly poor burn rate as this is insufficient mixing for a fast burning powder. Blackpowder also does not self confine on any scale that could be made in a mortar, and as such could not produce a supersonic bang and can not be the material described in the incident. I agree with James, a chlorate/sulfur mix is far more likely.

  4. I would have thought the instructor would have told the paramedics/attending physician what the chemicals were/proportions mixed so as that the “molten lava” could be removed, without further damage, if that was possible? Or are we assuming an instructor told a student to mix chemicals without even knowing what they were?

  5. For safety trainings we conduct, I think the CSB’s video “Experimenting with Danger” is a great eye-opener.


    We do workplace safety and first aid training for a variety of industries, and I’m amazed at the frequent and serious safety lapses I see in laboratories. Especially in an educational setting where students may not be fully aware of the properties of the chemicals they are just learning about, a good safety management program is essential.