Breathing Helium Can Be Dangerous

Once very early in my career as a teacher I had a large tank of helium near but not in the classroom. I filled some balloons with the helium and used in demonstrations in the classroom. I explained to the class that because helium atoms were so light in weight that when they replaced the air in our vocal cord area they allowed the vocal cords to vibrate much faster than they would normally causing the pitch of a persons voice to increase very noticeably. I asked the class which student they thought was the biggest problem in the class and literally everyone pointed to one boy in the class. Even he admitted that he tended to cause the most problems. I then told him I was going to breathe into my vocal cords some helium and then act like a teacher that was scolding him. I took in the helium, but tried not to take the helium all the way into my lungs and then proceeded to scold the student. The entire class started to laugh and the boy even broke into a broad smile because he realized that if a teacher were to scold him with such a high pitched voice it would not make much of an impression on him. Strangely, because he knew that I was "playing" with his world as the classroom problem child he suddenly actually felt better about me being his teacher and we got along quite well from that day forward.

I had other classes that day and did the same presentation, but I did very slightly feel the effects of the helium. Much later in my career I became much more aware of the many hazards that are potentially possible. If you take in too much helium you can become dizzy or even pass out. Large amounts could cause death and the taking in of any gas can cause gas bubbles to get into your bloodstream which could cause a blockage leading toward a seizure and even death.

Because the helium gas we get is under pressure it poses a danger from the pressure also. The tank could explode under certain conditions, a seal could break and if left unlocked it could be misused by others. In some recent television shows helium has been tested for the lifting power that it has to see if it could actually lift a person into the air. Because it would take a great deal of helium to lift a person and rather large balloons this is not likely to become a problem for a normal individual, but it could pose a problem for a small child or animal.

Fortunately helium is not combustible or reactive, so from that perspective it is relatively safe. I have considered doing experiments in the classroom with helium again, but with much more control. Now I might try to simulate the effect of helium on sound, but not the human voice. I would also not suggest allowing students or adults to breathe any helium even if they say they have done this before. I would want a way to lock the tank in such a way as to prevent tampering and misuse.

As a teacher with over thirty years I must admit that when I look back at the things we did "back then" in the classroom it is a wonder that we survived. I take a great deal more care now realizing that we often find out later about potential dangers in things we thought were safe.