Use lab agar for cooking
Technically agar has first been used (and still is) in the kitchen and then adopted to the lab.
In the 19th century, gelatin was used in the microbial laboratory. The problem is that gelatin is much less thermostable than agar and at higher cultivation temperatures plates will melt and get liquid again.
In 1882 the german microbiologistt Walther Hesse (at that time an assistant in Robert Kochs laboratory) followed the suggestion of his wife Fannie Hesse to use Agar instead of gelatin. See the two references for some interesting details.

I personally would never use anything which comes from the lab in my kitchen since you never know if there are any contaminants in there. This is also probably the reason, why your lab manager doesn't want you to have it.

References:


Walther   and   Angelina  Hesse-Early Contributors  to  Bacteriology
History of the agar plate