| Item name | 
			Index | 
		
		
			| Hydrogen purity (molar fraction) | 
			99.97% | 
		
		
			| Total non-hydrogen gas | 
			300 μmol/mol | 
		
		
			| Maximum concentration of a single impurity | 
		
		
			| Water (H2O) | 
			5 μmol/mol | 
		
		
			| Total hydrocarbons (calculated as methane) | 
			2 μmol/mol | 
		
		
			| Oxygen (O2) | 
			5 μmol/mol | 
		
		
			| Helium (He) | 
			300 μmol/mol | 
		
		
			| Total nitrogen (N 2 ) and argon (Ar) | 
			100 μmol/mol | 
		
		
			| Carbon dioxide (CO2) | 
			2 μmol/mol | 
		
		
			| Carbon monoxide (CO) | 
			0.2 μmol/mol | 
		
		
			| Total sulfur (calculated as H2S) | 
			0.004 μmol/mol | 
		
		
			| Formaldehyde (HCHO) | 
			0.01 μmol/mol | 
		
		
			| Formic acid (HCOOH) | 
			0.2 μmol/mol | 
		
		
			| Ammonia (NH2) | 
			0.1 μmol/mol | 
		
		
			| Total halogen compounds (calculated as halide ions) | 
			0.05 μmol/mol | 
		
		
			| Maximum particle concentration | 
			1 mg/kg | 
		
		
			| When the methane concentration exceeds 2 μmol/mol, the total concentration of methane, nitrogen and argon is not allowed to exceed 100 mol/mol |