Raw milk should not be consumed for people with a weak immune system or who are pregnant.
I found the kanji term for "pasteurization" and it is actually "sterilization" not pasteurization. The word is 殺菌 【さっきん.
Milk products that are pasteurized 低温殺菌 or "sterilized" will have the kanji 殺菌, and then the degrees in C in which it was sterilized. Milk that have NOT BEEN sterilized will be "無殺菌牛乳" or "not sterilized milk"
Some companies don't sterilize their milk.
I am not sure if MEGMILK sterilizes it or not. Most of MEGMILK's product line is described as "Raw Milk" 生乳 with NO indication of sterilization of the product: http://www.meg-snow.com/products/milk/7cf02.html
There is no "ESL" written on there either, which is another form of pasteurization (Extended Shelf Life).
"Raw Milk" is the kanji "生乳 【せいにゅう.
"Milk" is the kanji "牛乳" ぎゅうにゅう . The kanji is extremely similar looking.
In contrast, MEIJI milk products are sterilized. On this page you can see that their "raw milk" 生乳 product has all been sterilized for 2 seconds at 130 degrees C 130℃ 2秒間 : http://www.meijioishiigyunyu.com/lineup/
They even have a page dedicated to explaining their sterilization process and why they do it: http://www.meijioishiigyunyu.com/dictionary/
Tanna Milk Products are also sterilized:http://www.tannamilk.or.jp/product/milk.html
Hakodate Milk Products (sterilized):http://www.e-milk.co.jp/cgi-win/shop/i_lst.exe?shop/shop.ini+milk+B-00...
In conclusion and to answer my own question, the kanji you should look for is 殺菌 (sterilized), 無殺菌牛乳 (not sterilized), and 低温殺菌(pasteurized).
Here are some milk related kanji and terms:
低脂肪牛乳 Low Fat Milk
無脂肪牛乳 Fat Free Milk
加工乳 【かこうにゅう】 (n) processed milk;
加糖練乳 【かとうれんにゅう】 (n) sweetened condensed milk
還元脱脂乳 【かんげんだっしにゅう】 (n) reconstituted skim milk
乾燥牛乳 【かんそうぎゅうにゅう】 (n) powdered milk