SLAG WOOL

Description: SLAG WOOL — Mineral wool is any fibrous material formed by spinning or drawing molten mineral or rock materials such as slag and ceramics. It was first manufactured in the 19th century. Applications include thermal insulation, filtration, soundproofing, and hydroponic growth medium. Mineral wool can cause irritation to the eyes, skin and lungs, especially during its manufacture and installation..

Quick Facts:

• Category: other
• Also Known As: Slag wool, Mineral wool

Proven Benefits At A Glance:

• Slag wool is an insulation material made from industrial slag (a byproduct of metal production) spun into fibers
• It’s one of the most widely used insulating materials in Europe, accounting for over 50% of mineral wool insulation by volume
• Slag wool fibers are typically several micrometers in diameter
• Installation workers are exposed to lower lifetime levels of slag wool fibers than manufacturing workers
• Modern slag wool products may use various binder technologies, with some formulations moving away from formaldehyde-containing adhesives

Safety tier is a starting heuristic from regulatory status and comedogenic rating, not a dermatological verdict — see our Terms for the full disclaimer. Research confidence reflects how many real cited studies back this ingredient, not the strength of their findings.

🧪 SLAG WOOL

SLAG WOOL

CAS Number: —

Also Known As: Slag wool, Mineral wool

Category: other

Mineral wool is any fibrous material formed by spinning or drawing molten mineral or rock materials such as slag and ceramics. It was first manufactured in the 19th century. Applications include thermal insulation, filtration, soundproofing, and hydroponic growth medium. Mineral wool can cause irritation to the eyes, skin and lungs, especially during its manufacture and installation.

SLAG WOOL is an other ingredient used in skincare formulations.

🌍 Regulatory Status

📊 Comedogenicity

📚 Research & Evidence

🔬 The Science

Slag wool is manufactured by converting industrial slag—a molten byproduct from metal processing—into fine fibers through high-speed centrifugation or similar processes. The material’s properties depend on its chemical composition; specifically, something called the “acidity coefficient” affects how the slag crystallizes during cooling, which in turn influences the fiber characteristics and viscosity of the molten material (Materials (Basel), 2022). #1: Slag wool is a component of mineral wool insulation (MWI), a category that also includes glass and stone wool variants and represents over 50% of the insulation material market in Europe by volume (Glob Chall, 2022). #2: The fibers in slag wool products are inorganic and typically several micrometers in diameter (Glob Chall, 2022).

From an occupational safety perspective, workers who install slag wool insulation in buildings experience substantially lower cumulative lifetime fiber exposures than workers in slag wool manufacturing facilities (Regul Toxicol Pharmacol, 2003). Since epidemiological studies of manufacturing workers have not shown a significant increase in respiratory system cancer, the analysis suggests installer cohorts would face even less risk (Regul Toxicol Pharmacol, 2003). Regarding manufacturing processes, slag wool can be produced from chromium slag (an industrial waste) through detoxification in high-temperature furnaces, where harmful chromium compounds are converted to safer forms before fiber production (J Hazard Mater, 2018). Historical production methods involved exposure to other air pollutants beyond just fibers, including polycyclic aromatic hydrocarbons (PAH), zinc, lead, and carbon monoxide, though modern processes differ (Ann Occup Hyg, 1993).

#3: Traditional slag wool products use adhesive binders, historically phenol-formaldehyde-urea (PFU) formulations, but the industry is transitioning toward alternative binder technologies that reduce or eliminate formaldehyde emissions due to health concerns about formaldehyde exposure (Glob Chall, 2022).

💧 Skin Type Compatibility

⚠️ Don’t Combine With

🧴 Products Containing SLAG WOOL

📄 Related Research

Matched by search — not necessarily verified support for every statement above.

• Maxim LD et al. (2003). Fiber glass and rock/slag wool exposure of professional and do-it-yourself installers. Regul Toxicol Pharmacol.
• Tian T et al. (2022). The Effect of Acidity Coefficient on the Crystallization Properties and Viscosity of Modified Blast Furnace Slag for Mineral Wool Production. Materials (Basel).
• Zhao G et al. (2018). Pilot trial of detoxification of chromium slag in cyclone furnace and production of slag wool fibres. J Hazard Mater.
• Fallentin B et al. (1993). Simulation of past exposure in slag wool production. Ann Occup Hyg.
• Bennett TM et al. (2022). Low Formaldehyde Binders for Mineral Wool Insulation: A Review. Glob Chall.