Concentration (ppm)

Effects and Toxicity

100

No noticeable effects even after breathing for a few hours.

200

A mild headache in around 1.5 hours.

400～500

Headache, nausea and ear ringing in around 1 hour.

600～1000

Loss of consciousness in around 1 ~ 1.5 hours.

1500～2000

Headache, vertigo and disabling nausea in around 0.5 ~ 1 hour, and losing consciousness.

3000～6000

Headache, vertigo, disabling nausea...etc. in a few minutes. 10 ~ 30 minutes exposure can lead to death.

10000

Bring on immediate loss of consciousness and death.