Important information to know about Expiry Dates of Food or other Products.

1. Expiry date is the date from which the product will become unserviceable. That product is not supposed to be used after that date.
This expiry date for a product will be decided while developing the product. They will decide the period by conducting a shelf-life test in their laboratory. The BSI will prescribe the test conditions for various products. The people working on these products will have some knowledge about the microbiological and chemical properties of the substances they are using in making the product. They also will have an idea about the quality hazards of the raw materials used. They will also study the production process. They will also carry out the risk assessment. They will also conduct research to know the related hazards. Based on these facts they will fix up a tentative date and then conduct the shelf-life test. They will keep the product in prescribed conditions for one day, one week, one month and so on. They test the product as per the above sequence and find the quality of the product. If they find that the product is losing its quality after so and so time, That will be decided that date as the expiry date.
2. There is a difference between the expiry date and the best before. The product may not be harmful even though you consume the product after the best before date. But you will find that the quality of the product has come down and soon it may become harmful. The expiry date is over means the products are not useful. As per them, the product is to be discarded.
3. If the expert date sticker is wiped off, it is difficult to know the expiry date. While purchasing the food itself you should see the expiry date. If you find that the sticker is not there, you should ask the shop keeper to change the product. Otherwise, the shop keeper may have some other packets belonging to the same batch. You have to see those packets and take the same as the expiry date. If you see a food packet you will find both the manufacturing date and expiry date. That will give you an idea about the life of that product. Generally, the expiry date is to be printed on the packet but no sticker is to be used for indicating the expiry date.
4. It is not advisable to use the foods after the expiry date. Even in our house-made food products, we will find the difference in the taste after some time of its making. That is an indication that the food is getting spoiled. So we have to discard it. The food may not be harmful after that date also. But may not taste good to eat. I always suggest people not to eat food after storing it for some time. It is always better to eat fresh.
5. That is an individual's choice. Generally, in all these products some preservatives will be used. These preservatives will be good for a prescribed time period only. After that, the deterioration starts. So it is better not to eat them. But many may differ with this. They say no risk is involved. Maybe true bit definitely the taste will not be there. Even the house cooked rice also will give a foul smell after 3 days. Some people try to wash with water and eat.
6. The side effects of eating expired food will be different from food to food. In many cases, food poisoning will take place. In some cases, there will not be any bad effects. In some cases, one may get exposed to unwanted and dangerous bacteria. Some foods will lose their nutritional values and there is no use in eating such food.
But wasting food is not advisable. So it is better to purchase only the required quantity and consume them within the time duration mentioned there.

The expiry of food or expiry of any other item like chemicals and drugs is a very interesting study to do and based on past research and observations, an average useful period would be found for each of the item and an expiry date is mentioned about that particular lot of item. The expiry date does not mean that the item will become useless on the next day. It is not like that but it sincerely means that the characteristics of the material will start degrading around that time and after some time it would be totally useless for consumption. As a safety measure we discard it from the day one especially in case of the medicines. The detailed answers point wise to this query are as follows -

1. The expiry date of a product is based on the result of many food research and earlier experiences about it and for many items it is already established and new norms are found by the food scientists and specialist time to time in order to safeguard the health of people by mistakenly taking old and stale food. The expiry date is selected based on the test data of seeing the life of the food sample or sample of any other item by keeping it in the shelf for a long time and studying its characteristics when they start deteriorating making it useless for us.

2. There is a subtle difference between the terms 'Expiry date' and 'Best before date'. Expiry date means that after that date the item should not be used especially when it is a drug or chemical or even food item. For some drugs like eye drop or ear drop it is very crucial. On the other hand best before date means that even after that date one can take that if it looks good, smells good, and tastes good, and is acceptable. Best before date is generally used for food items. There is of course a catch in this that after the 'best before date' one cannot go using it indefinitely and that is where common sense comes in picture. There is also a legal point here that one cannot sell an item after its expiry date but can sell after the best before date and generally they are sold for a heavy discount. If you happen to visit a big store then sometimes there are items like 'buy 3 - get 5' type of advertisements. Check their expiry date and you will find that it might be actually approaching very fast.

3. If sticker is not there then go to the shop and find out about it by seeing it in a fresh item and then try to remember as when the item was last purchased in your house and make a rough calculation by extrapolating from the information got from the sticker on the fresh item and that is it.

4. The manufacturer or supplier is legally bound to mention the expiry date on the product but the user can decide to use it for a little time even after the expiry date based on how it was stored and what is its present condition. Generally old items start becoming rancid or tasteless with time. So one can use the item based on that information. There was a time when there was no concept of expiry date and people used their experiences in consuming the old items for a long period. In my village, during the 1960 - 1970 period, I have seen many methods of storing and keeping the old items intact after drying them in Sun and using for a long period especially during rainy season when we were not able to go out for anything. Whenever the items became stale we used to throw them based on our earlier experience.

Let me give one unique example of Glycerin which people use for moistening hands and body parts. I had an old vial and it was 15 years old. Normally their expiry date is mentioned something like 2-3 years. But that Glycerin looked good to me and I asked the doctor whether I can use that. He told that do not use it for internal purposes like cleaning of ear etc but could be used for skin as Glycerin does not degrade for a quite long time.

5. There is no fixed rule for this as we have to see for each and every item as how it is stored and kept so that it does remain edible for some little time even after the expiry date. This would require trial and error and will depend mainly on the storing and preserving. Let me give one example. Generally people take hot chapatis and discard the old ones. But if you keep them in a sealed container in freezer compartment and then heat them next day before consuming they appear as good as the fresh one. If you have a low temperature freezer you can experiment this for even after 2-3 days but slowly they start disintegrating and lose their moisture and taste. So these things require a lot of DIY experiments if one wants to find out the delayed time applicable for consuming them. From item to item it would be different. Further it depends on the climate of the place also as humid and hot climate is adverse to preserving.

6. Till the food is in good condition, there would not be any harm by the food even after some little time after the expiry date but one should be careful as sometimes in the stale food some microbes and pathogens might be produced and cause ailment in the user. Similarly in the cosmetic items the chemicals might degrade and do harm in place of the benefits for which they were bought.

The producers of food items want to make their consumers conscious of the safety norms of their products so that the consumers gets the entire informations relating to its date of manufacture, best date of use and its expiry date. With such informations, they would be able to manage the food products to be utilised in the specific time frame.
The queries as asked by the writer is indicated below providing them some hints of the related query -
1) The expiry date of a product is calculated upon their past investigations related to a particular product and how the bacteria's and other microorganisms are active in affecting the life of the product. It is their continuous research process and the latest findings are also taken into account to enhance the life of the product. If the scientists have developed certain variables for the betterment of the product, the same is thoroughly tested in the laboratory conditions prior to its introduction for the enhancement of the life of the product and finally it is included in the circuit.
2) No, both are the different conditions and need to be specified accordingly. Expiration date would indicate the last day beyond which it should not be used due to loss of its nutrients and flavours.
Best before date does indicate that the food is no longer in perfect condition from the date already specified indicating not necessarily that the food is no longer safe to be consumed.
3) You will have to see the lot number indicated on the external portion of the packet. You may contact the store from where it was purchased and show him the label of the packet. He can trace out the expiry date by going through the the lot number and even he would replace the packet on your request.
4) The food packet undergoes many transformations during its storage period though some preservatives are added to enhance its shell life but still odour, nutrients, flavours etc get deteriorated constantly and once the food is expired, it is not advisable to consume the same due to the unpredictable nature of the constituents of the food stuffs inside the packet.
5) It would depend upon what type of product you are using and who is its manufacturer. It could even produce good results though the product has entered into expiry phase but the result may be amazing due to additions of materials arresting its disintegration and retains the quality of the individual constituent even after the expiration of date. However, to remain the safe side, such products are to be discarded for consumption purpose.
6) The side effects may not produce immediately but that would take slowly and the consumers may feel stomach ache, headache, frequent passing of urine etc. Such effects may take place due to chemical reactions of the different constituents. The reaction may further aggravate due to the preservative being added to retardate the deterioration of the product. You should adhere to different dates such as the period of expiry and if expiry has occurred, it should be in no way to be consumed.

Earlier consumers were not so aware and often bought and used expired products, but currently, most people look carefully at the dates marked on each product while shopping. The expiry date is always the most important for any product at the time of purchase, this expiry date is taken care of for items used as food items, beverages, and medicines. But it is also true that everything or related product is safe only till that certain expiry date, it is not necessary. Expiry dates are a date that is estimated according to how long the use of the substance is best, which is related to the freshness of the food, not necessarily related to safety. Concerning this, we also need to understand other instructions. A sale date is also marked on the packing of the goods, which is for sales. This is considered a kind of guideline and based on this, to the date that sellers can sell that related product, not later than that. Many products also have a best if used by date, which means the same, the quality and taste of the item will remain intact if used up to the intended date. The guaranteed fresh date on the products indicates that the taste and fragrance of the product remain intact till the relevant date. There may be some changes after this date, but the product doesn't need to expire on that date. It is also true that some people sell products by using false labeling using deception. One should beware of such fraudulent people.

Everything has its survival period. Likewise, food item also has survival period. We should be careful while buying food items. If you buy any food item from the market then you will find the expiry date on each food packet. Without it, nobody is allowed to sell food item If one tries to do so then the person may be punished.
There is a difference between the 'expiry date' and the 'best before. Generally, the expiry date is calculated from that date when it has been manufactured whereas, 'Best before' means food items can be used after the prescribed date if the smell and appearance are good. People should not use food item after the expiry. It is believed that either food is poisonous or nutritional value is nil. If you take stale food then microbes and bacteria may produce which may create different disease in your body. Even Homemade food should not use after a certain period.