Photographer in shorts with no lab coat.
Not one person wearing safety glasses, including the teacher.
No long hair tied back, and often within the distance that flame can jump of a burning reaction or Bunsen burner.
(I used to be a girl scout leader. At a leader training a woman whose daughter had just had her very long hair cut, brought it to the training as we sat around a large campfire. The hair had no hair care products on it other than shampoo residue
- which is purposeful to make it easier to style - and the mom tied the hair shank to a long rod and gradually brought it closer and closer to the fire. The flame jumped to it when the hair was about 3 feet away.
It really made me think about Bunsen burners in the lab. So when my own daughter had her long hair cut, I took the shank to the lab on a Saturday and set up an experiment with a burner as the fire, the hair tied to an unattached ring stand
rod, and a metallic meter stick on the bench so I could get a distance from the flame result. I split the shank into three parts. The closest one ignited at 5.5 inches, the furthest at 8. The average was 6 inches. Remember now how often you have seen students
leaning towards their notebooks and having their heads close to the flame. And in case you weren't aware of it, all hair care products are organic and leave a residue on the hair to make it more manageable. Hair is flammable all by itself, but in the modern
world it it almost never by itself. The owner uses shampoo on it, and that increases flammability.)
Several shots of a girl's hand with long fingernails stretching out the gloves worn (a large chance of glove failure).
Not to mention, explosive reactions done on bench top with no shields.*
And reactions that release copious amounts of gas not in a hood.
And students doing the experiments or actually demonstrations, with apparently no safety considerations taken into account.
* The potassium chlorate and gummy bear demonstration I have done for my students every semester I taught, but in a fume hood, behind an explosion shield, and it's not just a thick walled test tube, it needs to be borosilicate glass (Pyrex or
Kimax) and even with that, I found the tubes get stressed enough for microscopic cracks to develop and if not taken out of service and replaced, when heated again and the fuel dropped in, the forces generated by the reaction can and often do blow out the bottom
of the test tube, spewing flaming oxidizer and fuel for several feet around the broken tube. In the video, it said thick walled tube, but not borosilicate, it was not done behind a shield, not done in a hood, not with a demonstration tray under it to contain
the potential fire spewing if it breaks, and students watching closer than the blast radius of a failing test tube (I've had it blow 4 or more feet away).
After learning by doing that glass failure is rather common, I wrote down data each time I did the experiment. [I changed the fuel to M&Ms or Skittles because unlike gummy bears they can roll and won't get stuck to the walls if the tube, and
in a hood, the tube needs to be at an angle to keep the reaction in sight and prevent destroying the hood itself if it exploded. The other advantage is that I made a gizmo from a pair of crucible tongs taped to a metal scoopula, to roll the candy into the
mouth of the tube and keep my hands well out of the way. And the candy coating gives a variety of colors of the rainbow, and is impressive.]
I found that on average an eight inch Pyrex test tube could be used 8 times without high rates of failure. But if used a ninth time about half of them broke and if it survived that and was used a tenth time, almost 100% of the tubes failed.
Had the tube in the video failed all those student would potentially have had flaming oxidizer and fuel sprayed all over them. And as I am sure you realize, such fires are almost impossible to put out. Fire departments routinely only try to stop such fires
from spreading, and here in Wisconsin, they are commonly happening on dairy farms. A farmer might store the bags of ammonium nitrate fertilizer in a shed where there are also sacks of seeds, or even rolls of hay in plastic so friendly microbes can turn it
into silage, which is higher protein for the cattle. Most farm sheds have metal roofs and get very hot on a summer day. So there you have it: strong oxidizer + organic fuel + heat = conflagration
Many of my students were in the fire protection degree program and their course requirements included learning about and seeing a strong oxidizer fire. I almost died from a potassium chlorate explosion my first year as a chemistry major in
college, so when I found out I needed to demonstrate this, I researched it and changed things to make it safe to demonstrate, and also to have it be impressive so they would remember it.
"It's better to be careful 100 times than to be dead once" Mark Twain