If I do a quick math of the recommended storage times1, then probably yes, but you could be getting very, very close to the "unsafe" threshold.
What you should change or eliminate is the storage and transport at room temperature part, because that will be the time of fastest bacterial growth. If you have access to a refrigerator at work, put your milk in it to cool it down quickly. If that's not possible, you'll need a form of insulated bag or container and ice packs. This will also be handy to transport the milk home - Bangalore can be quite hot, as we all know.
Mixing the milk is not really a problem, especially if you are pumping just for the next day, not for long-term storage. But make sure that whoever handles it does not warm the entire batch, just enough for one feeding. This is one of the reasons I personally preferred to store "single servings".
And especially where babies with their sensitive digestive system and breast milk are involved, it is better to be on the safe side...
1
Using the numbers from the CDC, cited here:
- 11:30 to 3:00 -> 3.5 hours or 7/12 of the 6h at room temperature window.
- This leaves 5/12 of the 5 days in the refrigerator, i.e. 50 hours.
Going by the (larger) numbers quoted here:
- 11:30 to 3:00 -> 3.5 hours or 7/12 of the 6h at room temperature window.
- This leaves 5/12 of the 4 days in the refrigerator, i.e. 32 hours.
Of course both numbers are estimates, so use common sense and cool the milk if possible.
Some recommended background reading on food safety from our sister site Seasoned Advice can be found here.