3 ms·

Hydrazine is so handy as a rocket fuel. It's room temp, stable, hypergolic, plenty of energy, it can even be a monopropellant. But it's also corrosive, extremel

Hydrazine is so handy as a rocket fuel. It's room temp, stable, hypergolic, plenty of energy, it can even be a monopropellant. But it's also corrosive, extremely toxic (even in the low-ppm range) and also carcinogenic. It's easily absorbed as a vapor and through the skin, and it'll kill you before you can smell it. There's good reason to not use the stuff in large quantities or in systems that are likely to be handled by humans for more than tanking it up. And nitrogen tetroxide ain't no picnic either. It's happy to fume, and those fumes will corrode your lungs and you won't know it. Then several hours or even days later, you're dead of pulmonary edema. LOX and kerosene are mother's milk in comparison.

ballooney 12y ago
I work in rocket propulsion research and have worked with, and around, both of these propellants, and I think you exaggerate to the point of being incorrect. You can smell hydrazine long before it's dangerous - it smells a bit fishy, somewhat like ammonia. It has to get really quite bad before your body-mounted gas alarms tell you that you're above recommended limits. I'm more worried by NO2 but as a fume it's bright orange so one can normally see a cloud of it coming and make plans to head somewhere not downwind. If you do get caught by some, protocol is to lie with your head at the bottom of an inclined plane for several hours, so the the fluid can drain out of your lungs (and you call an ambulance of course). When propulsion tests are happening on site we keep emergency breathing apparatus under our desks incase there's a containment failure and we need to get out. Usually though we just test when the wind direction would take anything away from the office/workshop. I'm not bothered about kerosene but I have a healthy respect for LOX; it's as easy to kill yourself with it as with hydrazine. Where breathing apparatus and chem suits will keep you safe from hydrazine pretty much, LOX doesn't forgive any dirtiness, grease, human hair, or the wrong choice of o-ring material, especially when pumped at high speeds and pressures. Different risks but LOX is arguably more likely to bite you. Here's an often-cited LOX safety video of the sort you probably couldn't make today: https://www.youtube.com/watch?v=QioE_OX4vP8 https://www.youtube.com/watch?v=QioE_OX4vP8
- 69_years_and 12y ago
  After reading the precautions you folk take - I hardy think the OP is exaggerating. Emergency breathing apparatus under our desks pretty much sums it up. With respect.

ballooney 12y ago

I work in rocket propulsion research and have worked with, and around, both of these propellants, and I think you exaggerate to the point of being incorrect. You can smell hydrazine long before it's dangerous - it smells a bit fishy, somewhat like ammonia. It has to get really quite bad before your body-mounted gas alarms tell you that you're above recommended limits. I'm more worried by NO2 but as a fume it's bright orange so one can normally see a cloud of it coming and make plans to head somewhere not downwind. If you do get caught by some, protocol is to lie with your head at the bottom of an inclined plane for several hours, so the the fluid can drain out of your lungs (and you call an ambulance of course). When propulsion tests are happening on site we keep emergency breathing apparatus under our desks incase there's a containment failure and we need to get out. Usually though we just test when the wind direction would take anything away from the office/workshop. I'm not bothered about kerosene but I have a healthy respect for LOX; it's as easy to kill yourself with it as with hydrazine. Where breathing apparatus and chem suits will keep you safe from hydrazine pretty much, LOX doesn't forgive any dirtiness, grease, human hair, or the wrong choice of o-ring material, especially when pumped at high speeds and pressures. Different risks but LOX is arguably more likely to bite you. Here's an often-cited LOX safety video of the sort you probably couldn't make today: https://www.youtube.com/watch?v=QioE_OX4vP8 https://www.youtube.com/watch?v=QioE_OX4vP8

69_years_and 12y ago
After reading the precautions you folk take - I hardy think the OP is exaggerating. Emergency breathing apparatus under our desks pretty much sums it up. With respect.