A practical reference for restoration contractors, plant engineers, hygienists, adjusters, and building owners evaluating CO2 blasting. It covers how the process actually cleans, where it outperforms across U.S. industries, the safety and documentation practices that hold up under review — and the jobs where another method is the right call.
Pellets at -109°F embrittle the contaminant and shrink it away from the substrate, breaking the adhesive bond at the interface.
Pellets accelerated by compressed air fracture the now-brittle layer. Energy transfers to the contaminant, not into the base material.
Each pellet flashes to gas and expands roughly 800x at the surface, micro-lifting debris away. The media leaves no waste behind.
Where CO2 blasting is established practice in the United States, and the standard each scope is typically written against.
Structural framing, sheathing, masonry, open-web trusses, HVAC housings
Acidic smoke residue etches metal and drives odor into porous wood. Dry ice removes soot and char from grain and mortar joints without adding water to a structure that is already being dried, and without the sanding dust that re-contaminates a cleared space.
ANSI/IICRC S700 (Fire and Smoke Damage Restoration, 2025)
Crawlspaces, attics, joists, band boards, subfloor sheathing, rim joists
Physical source removal from wood grain that sanding flattens and wet washing re-wets. No added moisture means no extended dry-down and a lower regrowth rate in humid climates.
ANSI/IICRC S520 (Mold Remediation) + third-party PRV clearance
Ovens, conveyors, dough hoppers, freezers, packaging lines, ceilings
Cleaning between shifts with no rinse water, no chemical residue, and no disassembly. CO2 is a recognized food-safe processing gas, and eliminating standing water removes a Listeria harborage vector.
USDA / FDA sanitation programs, HACCP cleaning validation
Weld cells, robotic fixtures, paint booths, tire and rubber molds, presses
Molds and tooling are cleaned hot and in place, cutting the cool-down and teardown out of the changeover. No media left in tooling cavities, no dimensional loss on precision surfaces.
OEM tooling-care specs, plant LOTO and confined-space procedures
Generators, stators, switchgear, insulators, turbine housings, substations
Non-conductive media allows cleaning of electrical apparatus without the drying and megger cycle a wet wash requires. Widely used during planned outages where the schedule is the constraint.
NFPA 70E work practices, utility outage procedures
Antebellum brick, lime mortar, heart pine, cast iron, limestone, plaster
Non-abrasive cleaning that satisfies review boards where sand or soda blasting would be rejected for eroding the fire skin of brick or scouring soft mortar. Documented test panels are the norm before full-scope approval.
Secretary of the Interior's Standards for Rehabilitation; NPS Preservation Brief 1 and 6
Composite tooling, jigs, landing gear bays, paint-booth fixtures, molds
Removes release agents and sealant residue without solvents, media entrapment, or substrate profiling on composite layup tools.
OEM process specs; FOD-control programs
Pre-1978 building components, structural steel, bridges, mill buildings
Used as a controlled removal step that generates far less waste volume than abrasive blasting, since only the coating enters the waste stream and not tons of spent media requiring hazardous characterization.
EPA RRP Rule; OSHA 1926.62 lead in construction
Match nozzle, pressure, and feed rate to what is underneath. Soft lime mortar, kraft-faced insulation, and painted drywall behave nothing like structural steel. Run a documented test panel on anything friable, historic, or coated, and photograph it before scaling.
On water and storm losses, structural drying comes first. Blasting wet wood drives residue into saturated grain and wastes media. Verify framing moisture against dry-standard readings, then blast, then insulate and close the wall.
The media disappears; the contaminant does not. Soot, mold, and lead become airborne particulate. Standard practice is critical barriers, negative air with HEPA, and post-blast HEPA vacuuming of horizontal surfaces before clearance.
Crawlspaces, tank interiors, pits, and closed rooms accumulate CO2 at floor level. Continuous monitoring plus mechanical ventilation is non-negotiable, and confined-space entry procedures apply where the space qualifies.
Production is compressor-limited far more often than machine-limited. Most single-hose units want 50 to 250 CFM at 80 to 145 psi with clean, dry air. Undersized or wet air is the most common cause of an underperforming job and pellet clogging.
Dry ice sublimates at roughly 2 to 10 percent per day in a good insulated container. Order for the day, not the week, and stage deliveries on multi-day scopes so consumption estimates hold.
Adjusters and hygienists accept scopes that read like reports: pre-condition photos, moisture and CO2 logs, method and pressure used, containment description, post-blast HEPA, and third-party verification results. This is what converts a restore recommendation into an approved claim.
Define what done looks like — clearance sampling, white-glove test, coating adhesion pull test, visual standard with reference photos — and agree on it in writing with the owner, hygienist, or plant engineer up front.
| Method | Media waste | Adds moisture | Substrate profile | Downtime driver |
|---|---|---|---|---|
| Dry ice (CO2) | None — sublimates | No | None | Access and containment |
| Sandblasting | High — spent grit | No | Aggressive profile | Grit reclamation and disposal |
| Soda blasting | Moderate — residue | Rinse usually required | Mild | Neutralize and rinse |
| Pressure washing | Wastewater | Yes — significant | None | Drying time |
| Chemical cleaning | Spent solution | Usually | Possible etching | Dwell, rinse, disposal |
| Hand sanding / wire brush | Dust | No | Flattens grain | Labor hours (50-70% higher) |
Deeper breakdown on the method comparison page and total-cost drivers on the cost guide.
Dry ice blasting accelerates solid CO2 pellets (-109°F / -78.5°C) through a compressed-air nozzle. Cleaning happens in three overlapping mechanisms: thermal shock embrittles and shrinks the contaminant layer so it loses adhesion to the substrate, kinetic impact fractures that brittle layer, and sublimation converts the pellet to gas with roughly an 800x volume expansion that lifts debris off the surface. Because the media becomes gas, the only waste stream is the contaminant itself.
No. Dry ice has a Mohs hardness of about 2 and sublimates on impact, so it does not create a surface profile the way sand (Mohs 7) or garnet does. That is why it is accepted for historic masonry, heart pine, aircraft tooling, and food-contact equipment where dimensional loss or profiling is unacceptable. Test panels are still standard practice on friable brick, lime mortar, and soft plaster.
Dry ice is non-conductive and adds no moisture, so motors, panels, PLC cabinets, bus bars, and control gear can be cleaned in place with appropriate LOTO and shielding. Many industrial scopes are performed hot and online, which is the primary reason plants adopt it: cleaning without cool-down and teardown removes days from the maintenance window.
CO2 displaces oxygen in confined or poorly ventilated spaces, so crews use CO2 monitoring with alarm thresholds (typically 5,000 ppm TWA / 30,000 ppm STEL per OSHA guidance), forced ventilation or negative air, hearing protection (nozzle noise frequently exceeds 100 dBA), eye protection, and insulated gloves for media handling. Fire and mold scopes add HEPA filtration, containment, and PPE per IICRC S700 and S520.
It is not a coatings-removal silver bullet. Thick, elastic, or well-bonded coatings (heavy epoxies, some powder coats), heavy rust scale requiring an anchor profile before recoating, and thick grease that smears rather than fractures are all better served by abrasive or chemical methods. It also does not sanitize by itself: dry ice at atmospheric pressure is not an EPA-registered antimicrobial, so mold and biological scopes pair blasting with HEPA vacuuming, source removal, and where specified an antimicrobial application.
Blasting removes mold growth and staining from wood framing physically, which is what remediation standards call for: source removal, not treatment in place. IICRC S520 is explicit that killing mold is not sufficient because dead spores and fragments remain allergenic. Best practice is dry ice removal, followed by HEPA vacuuming and air scrubbing, then third-party post-remediation verification.
Typical production rates run 50 to 250 lbs of pellets per hour depending on nozzle, feed rate, and pressure. Media consumption, not square footage, is often the dominant variable cost, which is why scopes are quoted by contamination type, access, and hours rather than a flat per-square-foot rate.
Line-item hourly cost is usually higher than hand sanding or pressure washing. Total installed cost is usually lower once you account for containment and reclamation of spent grit, wastewater capture and disposal, drying time before reassembly, production downtime, and the replace-versus-restore decision on materials and equipment that abrasive or chemical methods would damage.
Fire and smoke, mold, industrial, historic, and coatings scopes we perform.
Scoping language, documentation, and clearance evidence that gets claims approved.
Call 980-355-2189 or email Sales@Redi-co.com for a scoped estimate, 24/7.