Understanding Expiration Dates: Raw Materials vs. Finished Lotion
Question
I have questions about expiration dates and shelf life guarantees for cosmetic ingredients and finished products:
1. If I use ingredient A (Exp 06/2017) to make lotion with other ingredients (Exp 01/2019), must the resulting lotion be labeled with an expiration date of 06/2017?
2. Why is the phrase "at least 24 months" used in the "Storage" section instead of "at most 24 months"?
Answer
Hello! I understand you're new and have questions about expiration dates. The staff provided very clear information. Based on the information received, here's a summary:
The expiration date listed on the website for each ingredient (e.g., 06/2017) is the end date of the quality guarantee period from the manufacturer. This means that if the ingredient is stored according to recommendations, the manufacturer guarantees that the quality (efficacy) will remain at least 90% until the specified date. This date doesn't mean the ingredient will spoil immediately after this date, but it's the end of the quality guarantee period.
Now, to answer your questions:
If ingredient A (Exp 06/2017) is used to make lotion with other ingredients (Exp 01/2019), must the resulting lotion be labeled with an expiration date of 06/2017?
- No, that's not correct. The expiration date of the finished lotion is determined by the person who mixed it (you, in this case) after mixing and testing the stability of the formula. The expiration date of the finished product is determined based on the overall stability of the formula, not by the earliest quality guarantee date of the individual raw materials. Generally, cosmetic manufacturing standards often set the expiration date at 2 years from the production date, but it depends on the stability assessment of that specific formula.
Why is the phrase "at least 24 months" used instead of "at most 24 months"?
- The phrase "at least 24 months" in the "Storage" section refers to the minimum duration for which the manufacturer guarantees quality (at least 90% efficacy) if stored according to recommendations. It does not mean the ingredient can be used indefinitely after 24 months. All ingredients naturally degrade over time. The listed expiration date (e.g., 06/2017) is the end of this specific quality guarantee period. If stored correctly according to recommendations, the manufacturer guarantees the quality will be good for at least 24 months (or until the specified date). If the quality degrades faster than that under correct storage, it can be claimed.
I hope this explanation helps clarify things!