Grade	Total Purity by volume (%)	Maximum levels of impurities (ppm by volume)
		O2	H2O	N2	H2	CO	CO2	THC	N-oxides
Special	99.9995	1	1	3	ND	ND	ND	0.2	ND
UHP-I	99.9993	2	2	3	ND	ND	ND	0.2	ND
UHP-II	99.998	4	4	10	2	0.5	0.5	0.5	0.5
Cylinder Colour : Peacock Blue; with suitable grade identification label
Cylinder Valve : Right hand - conforming to IS 3224

Grade	Total Purity by volume (%)	Maximum levels of impurities (ppm by volume)
		O2	H2O	N2	Ar	CO	CO2	THC	N-oxides
Special	99.9995	1	1	2	ND	ND	ND	0.5	ND
UHP-I	99.999	2	2	10	ND	ND	ND	0.5	ND
UHP-II	99.995	4	4	40	ND	1	0.5	1	0.5
Cylinder Colour : Signal Red; with suitable grade identification label
Cylinder Valve : Left hand - conforming to IS 3224

Grade	Total Purity by volume (%)	Maximum levels of impurities (ppm by volume)
		O2	H2O	N2	Ar	CO + CO2	H2	THC	N-oxides
Special	99.9985	2	2	10	ND	0.5	ND	0.5	ND
Standard	99.995	4	4	40	0.5	1	ND	0.5	ND
Cylinder Colour : Middle Brown; with suitable grade identification label
Cylinder Valve : Right hand - conforming to IS 3224

Grade	Maximum levels of impurities (ppm by volume)
	H2O	CO2	THC
UHP-1	2	1	1
Cylinder Colour : French Grey; with suitable grade identification label
Cylinder Valve : Right hand - conforming to IS 3224