Table 1.

Major compounds and its concentrations for healthy persons.

Exhaled Breath	Concentration	Reference
Nitrogen	78.04%	[18]
Oxygen	16%	[18]
Carbon dioxide	4%–5%	[18]
Hydrogen	5%	[18]
Carbon monoxide	0–6 ppm	[19]
Ammonia	0.5 ppm–2 ppm	[20]
Inert gases and VOCs: Acetone, Isoprene and Ethanol	0.9% <1 ppm	[21]
Hydrogen sulphide	0–1.3 ppm	[22]
Nitric oxide	10 ppb–50 ppb	[6]
Nitrous oxide	1 ppb–20 ppb	[6]
Carbonyl Sulphide	0–10 ppb	[6]
Ethane	0–10 ppb	[6]
Pentane	0–10 ppb	[6]
Methane	2 ppm–10 ppm	[6]
Relative Humidity:
1. Oral Exhalation	91%–96%	[18]
2. Nasal Exhalation	82%–85%	[18]
Temperature Range	Between 34 °C and 36 °C	[18]