Hello, got a question...

[kaphri]

Hi, I'm a science fiction writer (oh, no, not another one of those!). Yep! And I need help on a short story that I'm working on.

I have human settlers trying to establish a colony on a distant planet. Their ship is on the surface and mostly intact. The surface of the world is adequate for colonization (no firm physical description yet). What I'm looking for is a harmful gas that will naturally develop and drive them back inside the ship. I have done some research on phosgene, and know that CHC, heated to a certain temperature, can create it. I see that it naturally occurs on earth in amounts that do not harm life. What circumstances would have to (suddenly) occur on a world for it to develop in a quantity that would be threatening and/or harmful? I understand that it concentrates close to the ground, so I can create a situation for its accumulation.
If there is another reaction/chemical that more reasonably fits this description, I'm open to suggestions.

I would deeply appreciate any help I can get on this.
My thanks in advance, and, if I have more questions, is it okay for me to contact you further through this site?
Bobbie

 

[oz93666]

You really don't have to go for a very deadly gas like phosgene , this is so poisonous it was used in WWI ...

ALL gases will kill in high concentrations , by virtue of them replacing oxygen ... Oxygen in higher concentrations (than 20%) will also be dangerous because small fires would become fierce very hot and out of control ....

On Earth around volcanic areas there is danger of death from SO2 , H2S or CO2 in low concentrations ... this are all released from magma naturally , probably the case on many planets

 

[kaphri]

Thanks for your help!

I'll do some research in the area of another gas replacing oxygen.