Questionable and non-Halal Ingredients.
All foods are considered Halal except: Swine / pork and all its by-products or derivatives, Carnivorous animals and birds of prey, Animals not slaughtered according to the Islamic requirements, Blood and blood by-products, Alcohol and other intoxicants, Foods that are contaminated with haram products, Food products and ingredients such as gelatin, enzymes, emulsifiers, etc. are considered Mash-booh and must be evaluated before they can be accepted.

Whey and Diary products
Depends on the enzyme used to curdle the milk. Normally the label does not make any distinction, so the products are suspected.
Check the source !

Emulsifiers
Commercially available mono and diglycerides may be manufactured from vegetable oil, beef fat or lard. If not labeled as vegetable, then product is considered suspected.
Check the source !

Enzymes
The source can be animal, plant or microbial. Normally the label does not make any distinction.
Check the source !

Flavorings
Complex ingredient (source of all ingredients ?)

Glycerine
No distinction on the label for source of glycerin (animal or vegetable) so any product containing glycerin is also suspected.
Check the source !

Microbes and Microbial Products
Halal as long as not harmful and not contaminated by najis. If the najis is not pork or pork derivatives that can be separated, the microbes or microbial products become halal after being purified by water. • The use of embryonic chicken eggs as a growth medium is allowed.

Meat
Authorized animal ? Halal Slaughtered ?
Check the source !

Anti-oxidants
Animal or plant source?
Check the source !

Gelatin
No distinction on the label for the source of animal, so any product containing gelatin is Haram or suspected.
Check the source !

Animal Fat or Protein
Authorized animal ? Halal Slaughtered ?
Check the source !

Alcohol drinks
Alcohol (intoxicants : ethanol) is prohibited in Islam. There is no allowance for added alcoholic drinks in food, cooking or formulations.
Ethanol

From alcoholic drinks industry :
Haram
From non- alcoholic drinks industry :
Allowed , as long as not harmful.
Ethanol residue :
- maximum 0.1 % in direct consumption product (to maximum 0.5 % depending on the nature of the product)
- max 1% in intermediate product (to be Halal certified)
By Products of Alcoholic Drinks Industry
1. Physically separated from alcoholic drinks and its dérivatives :
Haram – cannot be used at any level
2. Chemically reacted to be a new product :
Halal
3. Brewer yeast:
Halal if it’s already washed to remove the beer odor, taste and color
4. Vinegar:
Halal

L-Cysteine and other amino acids
Check the source !

Other ingredients ?
Check the source !