All info is courtesy of Vacuum Instrument Corporation (see bottom of first table).
Specifications (grams/year) R-12 Leak Rate Equivalent Helium Leak Rate For R-12 R-134A Leak Rate Equivalent Helium Leak Rate For R-134A Time Required for One Bubble to Form (Immersion Test) R-22 Leak Rate  Equivalent Helium Leak Rate For R-22 SF6 Leak Rate  Equivalent Helium Leak Rate For SF6
0.5 (0.018 oz/yr) 3.21 x 10-6 2.15 x 10-6 3.80 x 10-6 2.32 x 10-6 135.0 min 4.48 x 10-6 2.88 x 10-6 2.65 x 10-6 2.07 x 10-6
1.0 (0.035 oz/yr) 6.41 x 10-6 4.30 x 10-6 7.60 x 10-6 4.64 x 10-6 69.0 min 8.97 x 10-6 5.76 x 10-6 5.31 x 10-6 4.15 x 10-6
2.0 (0.071 oz/yr) 1.28 x 10-5 1.91 x 10-5 1.52 x 10-5 9.29 x 10-6 34.0 min 1.79 x 10-5 1.15 x 10-5 1.06 x 10-5 8.28 x 10-6
2.8 (0.1 oz/yr) 1.80 x 10-5 1.21 x 10-5 2.13 x 10-5 1.30 x 10-5 24.0 min 2.51 x 10-5 1.61 x 10-5 1.49 x 10-5 1.16 x 10-5
7.0(0.25oz/yr) 4.49 x 10-5 3.01 x 10-5 5.32 x 10-5 3.25x 10-5 10.0 min 6.28 x 10-5 4.03 x 10-5 3.72 x 10-5 2.91 x 10-5
14 (0.50 oz) 8.98 x 10-5 6.02 x 10-5 1.06 x 10-4 6.48 x 10-5 290.0 sec 1.26 x 10-4 8.09 x 10-5 7.43 x 10-5 5.80 x 10-5
28 (1.0 oz) 1.80 x 10-4 1.21 x 10-4 2.13 x 10-4 1.30 x 10-4 145.0.0 sec  2.51 x 10-4 1.61 x 10-4 1.49 x 10-4 1.16 x 10-4
(all leak rates in ATM-cc/sec)
© 2000 Vacuum Instrument Corporation 2099 9th Avenue Ronkonkoma NY 11779 631-737-0900
From std cm3/s Pa M3/s Pa L/s mbar L/s Torr L/s Kg Mole/s Air Molecules/s Air oz/yr Air mg/s
 
To
std cm3/s 1 0.1 101.33 1.01 0.76 4.46 x 10-8 2.69 x 1019 1.44 x 103 1.29
Pa M3/s 9.87 1 5.31 x 10-6 10 7.5  4.40 x 10-7 2.65 x 1020 1.42 x 10-4 12.75
Pa L/s 9.87 x 10-3 1.00 x 10-3 1 0.01 7.50 x 10-3 4.40 x 10-10 2.65 x 1017 14.19 1.28 x 10-2
mbar L/s 0.99 0.1 100 1 0.75 4.40 x 10-8 2.65 x 1019 1.42 x 103 1.28
Torr L/s 1.32 0.13 133.32 1.33 1 5.87 x 10-8 3.54 x 1019 1.89 x 103 1.7
Kg Mole/s 2.24 x 107 2.27 x 106 2.27 x 109 2.27 x 107 1.70 x 107 1 6.02 x 1026 3.22 x 1010 2.90 x 107
Air Molecules/s 3.72 x 10-20 3.77 x 10-21 3.77 x 10-18 3.77 x 10-20 2.83 x 10-20 1.66 x 10-27 1 5.35 x 10-17 4.81 x 10-20
Air oz/yr 1.49 x 10-4 7.05 x 10-5 7.05 x 10-2 7.05 x 10-24 5.29 x 10-4 3.10 x 10-11 1.87 x 1016 1 8.99 x 10-4
Air mg/s 0.77 7.84 x 10-2 78.41 0.78 0.59 3.45 x 10-8 2.08 x 1019 1.11 x 103 1
 
From ATM PSI TORR MICRON PASCAL mm Hg In Hg In Hg In H2O DYNE/cm² BAR MILLIBAR
  (0 deg C) (32deg F) (60deg F) (60deg F)
To        
ATM 1 14.7 760 7.6 × 105 1.01 × 105 760 29.92 30.01 407 1.01 × 106 1.01 1.01 × 10³
PSI 6.8 × 10-2 1 51.7 5.17 × 10-4 6.89 × 103 51.7 2.04 2.04 27.71 6.89 × 104 6.89 × 10-2 68.9
TORR 1.32 × 10-3 1.93 × 10-2 1 1.0 × 10³ 1.33 × 10² 1 3.94 × 10-2 3.95 × 10-2 5.36 × 10-1 1.33 × 103 1.33 × 10-3 1.33
MICRON 1.32 × 10-4 1.93 × 10-5 1.0 × 10-3 1 1.33 × 10-1 1.0 × 10-3 3.94 × 10-5 3.95 × 10-5 5.36 × 10-4 1.33 1.33 × 10-4 1.33 × 10-3
PASCAL 9.87 × 10-4 1.45 × 10-4 7.5 × 10-3 7.5 1 7.5 × 10-3 2.95 × 10-4 2.96 × 10-4 4.02 × 10-3 10 1.0 × 10-5 1.0 × 10-2
mm Hg 1.32 × 10-3 1.93 × 10-2 1 1.0 × 103 1.33 × 102 1 3.94 × 10-2 3.95 × 10-2 5.36 × 10-1 1.33 × 103 1.33 × 10-3 1.33
(0 deg C)
In Hg 3.34 × 10-2 4.91 × 10-1 25.4 2.54 × 104 3.39 × 103 25.4 1 1 13.6 3.39 × 104 3.39 × 10-2 33.9
(32deg F)
In Hg 3.33 × 10-2 4.90 × 10-1 25.3 2.53 × 104 3.38 × 103 25.3 9.97 × 10-1 1 13.6 3.38 × 104 3.38 × 10-2 33.8
(60deg C)
In H2O 2.46 × 10-3 3.61 × 10-2 1.87 1.87 × 103 2.49 × 102 1.87 7.35 × 10-2 7.37 × 10-2 1 2.49 × 103 2.49 × 10-3 2.49
(60deg F)
DYNE/cm² 9.87 × 10-7 1.45 × 10-5 7.50 × 10-4 7.50 × 10-1 0.1 7.50 × 10-4 2.95 × 10-5 2.96 × 10-5 4.02 × 10-4 1 1.0 × 10-4 1.0 × 10-3
BAR 9.97 × 10-1 14.5 7.52 × 102 7.50 × 106 1.0 × 106 7.50 × 102 29.5 29.6 4.02 × 102 1.00 × 106 1 1.00 × 103
MILLIBAR 9.97 × 10-4 1.45 × 10-2 7.50 × 10-1 7.50 × 102 1.0 × 102 7.50 × 10-1 2.95 × 10-2 2.96 × 10-2 4.02 × 10-1 1.00 × 103 1.0 × 10-3 1