Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) - focus on DnHexP (di-n-hexyl phthalate) impurity: What the SCCS Concluded About Safety in Cosmetics
Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) - focus on DnHexP (di-n-hexyl phthalate) impurity safety summary from SCCS/1678/25: SCCS conclusion, NOA.
is covered by SCCS/1678/25, an SCCS-family cosmetic safety opinion dated 2025-06-26. The opinion conclusion for this opinion is direct enough for a substance-specific summary: Considering the health concerns associated with DnHexP, the SCCS calculated a maximum safe level of 0.026% (260 ppm) for this impurity in the UV filter DHHB. This applies when DHHB is used up to 10% in cosmetic products and only if DnHexP is an unavoidable impurity.
Core Opinion Facts
- Opinion: SCCS/1678/25
- Opinion date: 2025-06-26
- Primary substance:
NOAEL Values Cited in the Opinion
The no-observed-adverse-effect data below is shown only from the SCCS source fields for this opinion. It is not a calculated margin-of-safety output.
| Endpoint | Value | Unit | Study context |
|---|---|---|---|
| Reduced ex vivo testosterone production; down-regulation of SR-B1, StAR, P450scc, 3bHSD, P450c17 gene expression (cholesterol transport and steroid synthesis) | 5 mg/kg bw/d | Sprague-Dawley rat (pregnant), gavage, Prenatal developmental toxicity in rats | |
| NOAEL | 2.5 mg/kg bw/d | Adjusted NOAEL for dermal back-calculation | |
| Ex vivo testis testosterone production (T Prod) | 10 mg/kg bw/d (deduced) | Pregnant rat (Sprague-Dawley); also CD-1 mice with DPeP, gavage, Short-term in vivo screen (Fetal Phthalate Screen FPS) |
Maximum Concentration or Conditions
| Use condition | Value | Unit |
|---|---|---|
| Concentration phrase in conclusion | 0.026% | |
| Concentration phrase in conclusion | up to 10% | |
| Concentration phrase in conclusion | maximum 10% | |
| Concentration phrase in conclusion | 10% |
Conditions from the Opinion
Applies only when DHHB is used up to maximum 10% w/w in cosmetic products; Only applicable if the presence of DnHexP in DHHB is unavoidable impurity resulting from a synthesis route; Target should be 1 ppm (DnHexP) given existence of alternative manufacturing processes
How to Read This Safety Conclusion
The key point for formulators is the match between the named ingredient, the cited NOAEL, and the SCCS conclusion. A NOAEL is a study point of departure, not a standalone permission to use at any level. The SCCS conclusion and any concentration or product-type conditions remain the controlling context for cosmetic use.
The source also matters because SCCS opinions can be ingredient-specific. The internal ingredient page for Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) - focus on DnHexP (di-n-hexyl phthalate) impurity should be treated as the substance hub, while SCCS/1678/25 is the opinion-level page for the committee record.
Practical Formulation Takeaway
For a formula review, start with the identity check: confirm the INCI name, CAS number, and opinion reference align with the material in the formula. Then compare the intended product type against the SCCS concentration or condition language above. If the formulation uses a different exposure route, product category, or concentration basis, the SCCS conclusion should not be stretched beyond what SCCS/1678/25 actually assessed.
Source
- SCCS opinion: SCCS/1678/25
- Source file: sccs_o_299.pdf
- Extraction JSON: SCCS Scientific Opinions