Generally the people think that the halal food is applicable to meat products only. It must be ensure that all foods specially processed food and non food products like pharmaceuticals and cosmetic products which need animals based & alcohol based ingredients including foods preservatives & colour in manufacturing may also haram, often these products contain animal by-products or other ingredients that are not permissible for Muslim consumption..
It is assumed that vegetable-based products are safe for Muslim consumption. But the Halal Certification System is not only with regards to the raw material used. It encompasses the whole production process which includes processing, packaging, labeling, storage and transportation.
The vegetable-based product is not naturally Halal if any of the production cycle is tainted with unclean elements (filthy or Najis) as in accordance with the Shariah Law. For instance, fats and oils or shortening is used during the process to enhance the taste of vegetable based food. Some of these enhancers may have been derived from a non-Halal animal. So many vegetable-bases products and their extraction are not completed without alcohol, the presence of alcohol in vegetable-based products are also haram to Muslim.
Beside it some vegetable fats are processed in the same machinery which has been used to process non-Halal animal fats. Further, some packaging may contain animal grease such as pork fats. If these packaging materials have been in contact with the Halal vegetable-based products in anyway, it will render those products Haram and unfit for Muslim consumption.
The production premises and facilities used must only be for the purposes of Halal foods production. The same premise and facilities are not to be used for both Halal and non-Halal food production. This is notwithstanding that those premises and facilities have been cleaned thoroughly as in accordance to the Shariah Law. This stringent measure is taken to prevent Halal foods from being contaminated with Haram elements or any other elements that are considered filthy (Najis) by the Shariah Law.
Halal certification is not only limited to food produce. Other products such as non-alcohol beverage, raw materials needed in food processing, pharmaceutical and health care products, traditional herbal products, cosmetics and personal care products, cleaning products, daily consumable products and leather-made products (e.g. shoes, furniture and hand-bag) are examples of things that have to be Halal for Muslim consumption/usage.
In addition to that, places like restaurants, hotels, canteens, food outlets, slaughtering houses; packaging and labeling materials are also required to have Halal certification to ensure they are suitable to be visited / used by Muslim consumers.