Table 1.

Phases of VHP cycles

	Phase (duration)
Trial	Conditioning (12 min)	G1 gassing (12 to 25 min)	G2 gassing (2 h 15 min)	Dwell (20 min)	Aeration (25 to 45 min)	Completion (30 to 45 min)
Vaporizer temperature (°C)
1	30.0	119.7	120.2	120.3	123.7	28.5
2	30.3	119.6	120.1	120.1	122.7	26.4
3	26.3	119.7	119.9	120.2	121.3	27.5
4	23.4	119.7	120.2	117.1	122.0	28.0
Mean	27.5	119.7	120.1	119.4	122.4	27.6
VHP concentration (ppm)
1			148	280	212	10
2			199	343	248	10
3			126	304	219	10
4			127	319	207	10
Mean			151	315	315	10
Airflow (m3/h)
1	17.7	43.7	42.6	42.8	44.4	49.3
2	17.8	43.1	41.7	41.9	42.9	48.2
3	16.4	44.2	43.4	44.0	44.5	46.1
4	16.4	44.5	43.6	43.6	45.4	46.2
Mean	17.1	43.9	42.8	43.1	44.3	47.5
Relative humidity (%)
1	46.7	50.2	72.7	87.2	79.4	49.1
2	41.6	46.3	75.0	93.5	84.2	46.6
3	50.4	52.7	75.0	95.8	86.1	53.4
4	52.8	53.2	75.0	99.4	89.4	58.4
Mean	47.9	50.6	74.4	94.0	84.8	51.9
Ambient temperature (°C)
1	25.6	23.9	24.5	25.3	25.2	26.4
2	26.6	24.1	24.6	25.2	25.0	26.4
3	24.5	24.0	24.7	24.5	25.2	25.6
4	24.1	23.8	24.2	25.3	25.1	25.8
Mean	25.2	24.0	24.5	25.1	25.1	26.1

As cycle phases completed, the vaporizer temperature emitted increased from the beginning of gassing until the end of aeration. The initial conditioning phase increases the temperature of the VHP vaporizer. Once optimal temperature is generated, the first gassing (G1 phase) is initiated followed by an increase of hydrogen peroxide vapor which is then detected in parts per million (ppm). Mean peak VHP concentration occurred during the dwell phase. Relative humidity and ambient temperature increased and decreased relative to cycle phases.