Skip to main content
. 2023 Mar 3;9(4):e14117. doi: 10.1016/j.heliyon.2023.e14117

Table 3.

Significant toxicity of inhaled carbon dioxide at low levels in animal studies.

Experimental study,
species
Toxic CO2-level (Vol%)
[exposure duration]
Significant Outcome
FDA Technical
Reports 1979 [106]
guinea pigs
0.48 %
Exposure to pregnant
[10 min over 20 days each]
Stillbirth and birth defects
(67.5%)

Howard 2012 [58]
rats
3% resp. 0.8 %*
Exposure to pregnant
[chronically]
Stillbirth and birth defects
(p < 0.01)

Kiray 2014 [108]
rats
0.3 %
Exposure to unborn (pregnant)
[chronically]
Neuron destruction in prefrontal cortex and hippocampus,
decreased IGF-1 levels,
increased anxiety after birth,
impaired memory and learning
(p < 0.05)

Uysal 2014 [113]
mice
0.3 %
Exposure to adolescent
[chronically]
Neuron destruction in gyrus dentatus and the prefrontal cortex,
decreased IGF-1 levels,
less activity, increased anxiety,
impaired learning and memory
(p < 0.05)

Vandemark 1972 [114]
rats
2.5 % resp. 0.5 %*
Exposure to male
[4 hours]
Destruction of spermatid and Sertoli cells in testes,
streaking & vacuolization of the tubular components,
no maturation of spermatids
(histopathological proof)

*Calculated for humans with an interspecies safety factor, for further details see Howard et al [58,107,115].