Regulatory exposure limits:
ASHRAE Standard 62-1989
: 1000ppm. CO2
concentration in occupied building should not exceed
1000ppm.
OSHA
: 5000ppm: Time weighted average over five 8-hour
work days should not exceed 5000ppm
Building bulletin 101 (Bb101)
: 1500ppm. UK standards
for schools say that CO2 at averaged over the whole
day(i.e. 9am to 3.30 pm) should not exceed 1500ppm.
Germany, Japan, Australia, UK
...: 5000ppm. 8 hours
weighted average in occupational exposure limit is
5000ppm.
CO2 LEVELS AND GUIDELINES
Non-enforced reference levels:
a) 250~350ppm– Background (normal) outdoor air
level.
b) 350~1,000ppm – Typical level found in occupied
spaces with good air exchange.
c) 1,000~2,000ppm – Level associated with
complaints of drowsiness and poor air.
d) 2,000~5,000ppm – Level associated with
headaches, sleepiness, and stagnant, stale, stuffy
air. Poor concentration, loss of attention,
increased heart rate and slight nausea may also be
present.
e) > 5,000 ppm – Exposure may lead to serious
oxygen deprivation resulting in permanent brain
damage, coma and even death.
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