Safe Operating Area is also sometimes called derating in datasheets, if you don't find any graphs or statement in the datasheet that specifies this area then you should apply by yourself some margin over the maximum operating conditions to ensure safety and durability of the component.
Here are some safe margins that you can apply if you have no indications in the datasheet :
For BJT transistors, do not exceed 30% of the maximum specified power, and do not exceed 70% of VCE, ICE and VBEinv maximum specs.
For MOSFET, do not exceed 70% of VDS and 75% of junction temperature. You can apply 100% of the maximum spec for VGS. In the case of switching power supplies, derating of these 3 values can be brought to 90% (mandatory for VGS).
Hope this helps.