You should look at the data sheet. It will tell you stuff like the max temp and max current and so on.
This information isn't about the specific part you have asked about but a couple weeks ago RECOM offered a book, Free on PDF, and for a nominal cost in paperback that has a chapter on Reliability in which they explain how a parts predicted lifetime is calculated. If you have an interest give it a look. The chapter of the book in question is 7 on page 171 called Reliability. Here is the link to the E-14 Forum Posting.
How can I determine the expected life time of a component? I the expected life time is dependent of various properties like temperature. But I try to determine the expected life time of this component: QRE1113GR - FAIRCHILD SEMICONDUCTOR - OPTO CPLR, PHOTOTRANSISTOR O/P, SMD-4 | Farnell element14
- What is the estimated life time of the compent (max current, 25 celsius, normal operation)
- How can I extend the expected life time? (less current through the IR led?) What is the estimated life time of the component if I use the led on 50% current.
- Is the life time of other reflective phototransistors the same?
- Other information about how to determine the life time of a product.