The MLP and MLS meet the 25 year shelf life capability of tantalum capacitors. The concern for shelf life is that the DC leakage current might increase with storage at warehouse temperatures sufficiently, that when the capacitors were put into application, they would fail by venting from the pressure of the hydrogen gas created by the high leakage current. To check that out CDE put capacitors on accelerated shelf life storage at temperatures of 65°C, 85°C and 105°C. The designer considered ten-times increase in DC leakage as acceptable because it would not cause venting. Capability decreases with increasing voltage and, so, the worst performer was the 120µF 400V rating that lasted 2000 hours at 85°C, and that is a little more than 5 years at 40°C, typical warehouse storage temperature. Both the 820µF 200V and the 11,000µF 50V capacitors lasted more than 4000 hours at 105°C without exceeding 10 times DC leakage. That is more than 41 years at 40°C and 25 years at 47°C.