The objective of the Safety-in-Use (SIU) test is to determine the potential of a product to elicit an irritant response under real-life use conditions. This study is often suggested following completion of the Human Repeated Insult Patch Test (HRIPT) and provides information on the likelihood of the test product to irritate the skin under normal or exaggerated use conditions. For statistical relevance, it is recommended that no fewer than 30 subjects complete the study. However, the more subjects tested, the more reliable the results will be.  For baby or children’s products, the study can be run using subjects within the appropriate age range after receiving approval from an Institutional Review Board (IRB). The duration of a SIU study may be any length of time, but a two week or four week study design is typically used. For products whose intended use is more or less frequent than daily applications, a shorter or longer study duration may be recommended.  Eurofins CRL technical staff can help advise on study design for your specific product.


Individual units of the test product must be provided by you, the Sponsor, in a quantity sufficient to last each subject for the number of required uses. Eurofins CRL staff will label each unit with identifying study and subject numbers prior to distribution. At the baseline visit, the skin on the area of intended product use is examined by a dermatologist or trained staff. The absence of any dermal conditions or irritation is confirmed prior to enrolling the subject. Test sites are graded for erythema, edema, and dryness. Subjects are provided with the test products, instructions for use, and a daily diary in which to record each use. At the end of the specified study period, subjects return for a final, post-use evaluation. Dermal examinations are performed and levels of erythema, edema, and dryness are recorded. If desired, a final questionnaire may be provided for completion by each subject in order to obtain consumer opinion of product attributes.

Interpretation & Reporting of Results

Following study completion, results of dermal evaluations as well as any reported Adverse Events will be reviewed by the Principal Investigator.    Generally, an increase in mild dryness observed in a few subjects is not clinically significant and may be due to current weather conditions. Evidence of erythema, edema, or other rashes on the test sites may be indicative of irritation from or allergy to the test product. Further testing of the involved subjects may be suggested to confirm relationship to the test product.

At the request of the Sponsor, unaudited topline results may be provided verbally or in writing approximately one week after study completion. An audited Final Report follows shortly thereafter.

Scheduling a Safety-In-Use study

To schedule, please contact your Client Services representative at 732-981-1616 or contact us by e-mail: