Table 2.

Average mass gain (wet and dry mass gain*) of CP Mg, AM50 and AZ91 after 96 h exposure at 95% RH and 22 °C, in the presence and absence of CO₂.

Sample condition	CO2 concentration (ppm)	Mass gain (µg/cm2)
		Material
		CP Mg	AM50	AZ91
Wet	400	70 ± 5	165 ± 41	61 ± 6
	0	52 ± 2	66 ± 7	40 ± 2
Dry	400	15 ± 3	30 ± 8	4 ± 1
	0	12 ± 4	18 ± 6	2 ± 0

*Wet mass gain: Mass gain measured directly after the exposure ends. Dry mass gain: Mass gain measured after 24 h drying over a desiccant at room temperature and ambient pressure.