Isopropyl butyrate (CAS 0638-11-9) — Citrus Top Note Fragrance Ingredient
Isopropyl butyrate
CAS 0638-11-9
What Is Isopropyl butyrate?
Isopropyl butyrate is a synthetic ester commonly used in fruity fragrances and flavorings. You’ll encounter it in tropical-scented body care products and some citrus-forward perfumes. This ingredient matters because it provides a bright, juicy pineapple-like note that’s more stable than natural fruit extracts, helping fragrances maintain their character over time.
Safety Profile
GENERALLY SAFEWhat Does Isopropyl butyrate Smell Like?
Isopropyl butyrate bursts with a vibrant, sun-ripened pineapple character – think golden fruit flesh dripping with juice. The top note has a slightly boozy, rum-like warmth that quickly settles into a candied tropical fruit basket. As it dries down, it reveals a softer, creamier undertone reminiscent of coconut milk swirled with vanilla. The overall effect is like biting into a perfectly ripe guava while standing in a pineapple field at midday.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the tropical coconut-pineapple accord, creating a photorealistic beach cocktail effect that lasts longer than natural fruit notes.
Serves as the primary pineapple note in this Aventus-inspired fragrance, providing bright fruity top notes with excellent diffusion.
Chemistry, Properties & Perfumer Guide
The Chemistry
Isopropyl butyrate is a simple ester formed by the condensation of isopropanol and butyric acid. Industrially produced via acid-catalyzed esterification, it’s part of the fruity ester family that includes similar molecules like ethyl butyrate. The molecule lacks chiral centers, making synthesis straightforward without stereochemical considerations. Its volatility stems from the relatively small molecular weight and non-polar character, while the ester linkage provides enough polarity to carry the scent in both oil and water phases.
Physical & Chemical Properties
| Boiling Point | 130-132 °C |
|---|---|
| Density | 0.86 g/cm³ |
| Refractive Index | 1.389-1.393 |
| Flash Point | 26 °C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Tropical fruit accords |
| Body Care | 0.1-1% | Up to 2% | Shower gels, shampoos |
| Candles | 0.5-2% | Up to 3% | Tropical home fragrances |
Classic Accords
Tip: Use with citrus top notes to prevent the pineapple character from becoming too candied.
Alternatives & Comparisons
More intense pineapple character with higher volatility, better for short-lived top notes in air fresheners.
Provides a more natural, fleshy pineapple note but requires higher usage levels.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA standards.
GHS Classification
RIFM Assessment
RIFM considers isopropyl butyrate safe for current fragrance use levels.
Sustainability
As a synthetic material, isopropyl butyrate has minimal environmental impact in production. It’s manufactured from petrochemical feedstocks via efficient catalytic processes. Unlike some tropical fruit extracts, its use doesn’t contribute to deforestation or habitat loss. The molecule is readily biodegradable under standard OECD test conditions.
Explore Isopropyl butyrate
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. Book reference
- Arctander, S. (1969). Perfume and Flavor Chemicals.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data error
