Irritation testing- how does it work?

I made a product for a client and they are inquiring about irritation or adverse reactions that are possible using the product. 

I know some vendors have offered to do irritation testing.  Can anybody elaborate on this?  Is this additional testing we can send to an outside lab to do so we can have this data ?  any suggestions


  • There are several types of irritation studies:

    1 Patch testing. They place several dilutions under adhesive tape on the skin. Leave for 6-24 hours and see which ones caused allergic reactions from redness to blisters.
    They may give a false positive for rinseoff products, which won't cause much irritation if quickly and completely rinsed off.
    It ain't that expensive or complicated, but at least hire a pro to apply it and check the results.

    2 Normal use testing. They ask volunteers to use the product as intended. They then check for redness or irritation.
    Not too expensive or complicated but usually requires more paid volunteers than #1.

    3 Cell culture testing. Expensive, complicated and may be unrelated to real world use.

    You can provide them some info from the separate ingredients, and extrapolate to the finished product.
    If the client pays for it, you can arrange some patch testing. Just warn them that even incomplete rinsing ain't as bad as reactions behind an occluded patch.
  • I would add

    4. HRIPT (long test: 6 weeks, and need many volunteer e.g. 50)
    5. Open test (duration max 5 days)

    Both allow you to add the claim " tested under dermatological control"
    HRIPT allows also the claim "Hypoallergenic product" and "
    minimizes allergy risks" 

  • There is a guy that came up with an irritancy test, can't think of his name?
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • Have a look at the Lanman-Maibach cumulative Irritation Test. I would look it up but have to go to bed.
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • Thank you for the responses...
    would I need to go to a regular testing lab for these type of tests?

    I also understand that vendors normally may not do testing on certain parts of the body. Could I request this type of testing also?
  • Hello ,
           You can use zein test also,for checking irritancy  of your product.Zein number gives irritation potential...
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