Mapap Sinus PE?
http://www.rxlist.com/drugs/drug-94909-Mapap+Sinus+PE+Oral.aspx?drugid=94909&dru
gname=Mapap+Sinus+PE+Oral

You can also contact the poison control center, or the FDA
(http://www.fda.gov/cder/Offices/DDI/drugID.htm)

I found some Light green pills with "L690" imprinted on the top.
Can anyone help me identify this please?
I found these pills my sons room, he is only 12.

By the clues you gave,
I went to this very helpful website:

http://www.drugs.com/pill_identification.html

Here is the information I came up with.
The photo shows a greenish, capsule shaped pill.
Drug Name
Tace (Chlorotrianisene)
Strength
12 MG
Imprint
MERRELL 690
Manufacturer/Distributor
Aventis Pharm
*Tace*
Chlorotrianisene is a form of estrogen.
Estrogen is a female sex hormone necessary
for many processes in the body.

Is this what you found in your son's room?
Take care,
Cathy
www.mycowcorner.com