Fiberlock ShockWave vs Concrobium Decision Guide

Why this matters

ShockWave (Fiberlock Technologies) and Concrobium Mold Control (Siamons International) are the two products most commonly mis-substituted on remediation trucks. They are not the same chemistry, they have different EPA registrations, they treat different stages of the job, and they leave different residues. Picking the wrong one because the bottle is closer to hand produces a clearance failure or a product-incompatibility callback. This article gives the chemistry, the use case for each, and the decision matrix.

Chemistry side by side

Fiberlock ShockWave (EPA registration 73232-1) is a quaternary ammonium chloride disinfectant cleaner concentrate. Active ingredients include alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl ethylbenzyl ammonium chloride at combined concentration around 3.25 percent in the concentrate. Diluted at 1:64 for general antimicrobial work, 1:8 for heavy mold pre-treatment. Quat-class chemistry. Leaves a cationic residue that is mildly tacky to surfaces until dried.

Concrobium Mold Control is a no-salt formulation of sodium carbonate, trisodium phosphate, and sodium bicarbonate in water, sold ready-to-use. EPA exempt under 25(b) because the active ingredients are on the EPA minimum-risk pesticide exempt list. It is not a registered biocide. The mechanism is mechanical: as the water carrier evaporates, the dissolved salts form a thin crust that physically crushes mold cells and forms a moisture-managing barrier on the substrate.

These are fundamentally different products. ShockWave is a biocide. Concrobium is a desiccating barrier coating.

Where each one fits in the workflow

ShockWave is used as:

• Pre-clean antimicrobial spray on a Condition 3 surface before physical removal, to suppress airborne dispersion of viable spores during demolition
• General-purpose surface disinfectant on framing, sub-floor, and other semi-porous structural materials after physical removal
• Source-tank product in an ULV fogger when a labeled space-spray antimicrobial is required (verify ULV use is on the current label revision)
• Heavy mold pre-treatment at 1:8 dilution as called out on the label

Concrobium is used as:

• Encapsulant-style finishing coat on Condition 2 or post-cleaned Condition 3 surfaces (framing, OSB sheathing, semi-porous substrates) where the customer or insurer wants a residual moisture-management film
• Treatment of inaccessible cavity sides through injection ports, where the film-forming action discourages regrowth at low cost
• HVAC interior surface treatment under the manufacturer's label allowance for HVAC use, after physical cleaning is complete

Substrate compatibility differences

ShockWave at 1:8 dilution can etch certain paints, oxidize bare copper trim, and discolor zinc-galvanized fasteners on prolonged contact. Quat chemistry deactivates on contact with anionic surfactants and on contact with cellulose surfaces it has bonded to (cationic adsorption to fiber). This means ShockWave residue on a fabric or carpet binds the active ingredient and reduces its biocidal effect over time. Do not apply ShockWave to a substrate the homeowner needs to repaint without a thorough water rinse and dry; the quat residue interferes with paint adhesion.

Concrobium is compatible with paint, wood, drywall, metal, and most plastics. The dried film is white and lightly visible on dark substrates; it is meant to be paintable but on aesthetic finished surfaces you will see a chalky residue. For visible interior finished surfaces, apply Concrobium only after the substrate is confirmed paintable, then rinse, dry, and prime.

Cost-in-use difference

ShockWave concentrate yields about 64 gallons of ready-to-use at general dilution per 1 gallon of concentrate. The cost per ready-to-use gallon is low; a 5 gallon pail of concentrate covers a multi-job week.

Concrobium ships ready-to-use only; 1 gallon equals 1 gallon. The cost per applied gallon is higher than diluted ShockWave by approximately 4 to 8 times depending on case price. On a single Condition 3 cavity treatment, this is not material. On a 5000 square foot crawlspace finish coat, it is.

For estimating purposes, treat Concrobium as a finishing material with a per-gallon line item, and ShockWave as a labor-driven disinfectant with a per-job consumable line.

Regulatory and label use

ShockWave is EPA-registered. The label allows specific use patterns: surface disinfection, mildewstatic, fungistatic, hospital disinfectant, ULV space spray (depending on label revision). Operators must follow the label dilution, dwell time, and PPE. OSHA 29 CFR 1910.1200 SDS must be on site. ULV use requires fit-tested respiratory protection per OSHA 29 CFR 1910.134.

Concrobium is EPA-exempt under 25(b). The label is not subject to FIFRA-registered claim limits, but the manufacturer label still governs use and operators should follow it. The product cannot be marketed as a registered antimicrobial. Customers asking for an EPA-registered antimicrobial residue need ShockWave or another registered product instead.

Decision matrix

Use ShockWave when:

• The scope calls for surface disinfection or pre-clean of a Condition 3 surface
• Insurance specifies an EPA-registered antimicrobial
• ULV space-spray application is the delivery mode
• The substrate will be removed or covered after treatment

Use Concrobium when:

• The scope calls for a residual encapsulant film on semi-porous substrates that will remain in service
• The substrate is paint-sensitive, metal-sensitive, or fabric-adjacent
• The work is in an occupied space and the customer prefers a low-toxicity treatment
• HVAC interior treatment is in scope (within the label allowance)

Use both, in sequence, when:

• The job is a wall cavity that must be cleaned then encapsulated. ShockWave at the pre-clean step, full water rinse and dry, then Concrobium as the finish coat.

What not to substitute

Do not substitute Concrobium for ShockWave on a disinfection step where insurance is paying for a registered antimicrobial. The audit will catch it.

Do not substitute ShockWave for Concrobium as a long-residual encapsulant. The quat film is not a moisture barrier and is not labeled as one.

Do not blend the two in the same tank. The cationic quat reacts with the alkaline carbonate chemistry in Concrobium and precipitates both out of solution.

References

• Fiberlock Technologies ShockWave EPA Master Label, Reg No 73232-1, current revision.
• Siamons International Concrobium Mold Control Product Safety Data Sheet and use guide.
• EPA Minimum Risk Pesticide Exemption under FIFRA Section 25(b), 40 CFR 152.25.
• ANSI/IICRC S520-2024 Standard and Reference Guide for Professional Mold Remediation, Annex B (Antimicrobials).
• OSHA 29 CFR 1910.1200 Hazard Communication Standard.