What Is Quaternium-98?
Quaternium-98 is a quaternary ammonium compound created by linking a plant-derived fatty amine called lauryl propylenediamine to small chains of ethylene oxide, then reacting that mixture with lauric acid and finally quaternizing it with dimethyl sulfate. The result is a positively charged, water-dispersible ingredient that loves both oil and water, making it easy to spread across hair or skin.
“Quats” have been beauty staples since the 1950s for their knack for smoothing and softening. Quaternium-98 is part of a newer generation designed to give that classic silky feel while rinsing clean and resisting product buildup. Because it is produced in a controlled factory setting, the material is consistent from batch to batch and can be tailored to different formulas by tweaking the length of the ethoxylate chain or the fatty acid used.
You will spot Quaternium-98 most often in rinse-off and leave-in hair conditioners, masks, anti-frizz sprays, detangling creams, and color-protecting treatments. Skin-care brands also add it to light lotions, body butters, after-sun gels, and shaving products to boost slip and softness.
Quaternium-98’s Cosmetic Benefits/Uses
The ingredient delivers several benefits that help products feel better and perform better on hair and skin
- Hair conditioning – The positive charge in Quaternium-98 is attracted to the negative charge on damaged hair fibers. It forms a thin layer that smooths cuticles, reduces static, makes detangling easier, and leaves hair looking shiny and feeling soft
- Skin conditioning – When used in lotions or creams it leaves behind a silky film that reduces roughness and helps skin feel supple without a greasy afterfeel
- Emollient – Its fatty acid portion fills in gaps on the surface of hair and skin, sealing in moisture and giving products a creamy, spreadable texture
Who Can Use Quaternium-98
Most skin types, including dry, normal, oily and combination, can use products containing Quaternium-98 thanks to its lightweight feel and low likelihood of clogging pores. People with very sensitive or compromised skin should proceed with a bit more caution because any cationic conditioning agent has a small chance of causing irritation on already inflamed skin.
The ingredient is typically sourced from plant oils and synthetically processed, making it suitable for vegans and vegetarians. No animal-derived substrates are used in standard manufacturing.
Current research has not flagged Quaternium-98 as a concern for women who are pregnant or breastfeeding. Still, this is not medical advice and anyone expecting or nursing should show the product label to a qualified health professional for personalized guidance.
Quaternium-98 does not increase photosensitivity so it will not make skin more prone to sunburn. It is also generally considered color-safe for dyed hair and plays nicely with other common cosmetic ingredients.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Quaternium-98 differ from person to person. The points below list potential reactions but most users will not experience them when the ingredient is properly formulated and used as intended.
- Skin irritation – mild redness stinging or itching on very sensitive skin
- Contact dermatitis – rare allergic rash after repeated exposure
- Eye irritation – watering or burning if the product accidentally gets into eyes
- Scalp buildup – limp or coated hair when large amounts are left on without rinsing
- Interaction with exfoliants – increased tingling when layered over strong acids or alcohol-heavy toners
If any of these effects occur stop use immediately and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 1/5
Quaternium-98 is highly water dispersible and carries a positive charge, so it tends to sit on the surface rather than sinking deep into pores. Its fatty portion is balanced by a sizable ethoxylate chain that keeps the molecule light and less likely to form the dense plugs linked with breakouts. In consumer use and safety data, reports of acne flare-ups are rare.
This low score means products containing Quaternium-98 are generally suitable for acne-prone or easily congested skin, especially in rinse-off formats like conditioners or body washes.
The only caveat is heavy leave-on creams layered with multiple occlusive ingredients; in those cases overall formula richness, not Quaternium-98 itself, is the bigger concern.
Summary
Quaternium-98 works as a hair conditioner, skin conditioner and emollient. Its cationic charge homes in on damaged hair cuticles, smoothing them so strands feel soft, detangle easily and gain reflective shine. On skin the same film-forming action fills in surface roughness, giving lotions a silky glide without a greasy finish.
While not a household name, it is a quiet favorite among formulators who need reliable slip and antistatic performance that rinses clean. You will spot it more often in modern conditioners and styling creams than in classic skincare, though its use in light body lotions is growing.
Safety testing shows a low risk of irritation or sensitization for most users. Still, every person’s skin is unique so it is smart to patch test any new product containing Quaternium-98 before full-scale use.