IICRC S700 — Standard for Professional Fire and Smoke Damage Restoration

S700 is the Standard and Reference Guide for Professional Fire and Smoke Damage Restoration. Published by the IICRC and updated every several years (current version: S700-2021), it's the industry reference for any fire or smoke loss above small-area limits.

S700 covers five areas: (1) smoke residue identification and characterization, (2) structure cleaning chemistry, (3) contents handling — what gets cleaned on-site vs. packed out, (4) deodorization — thermal fogging, hydroxyl generation, ozone, and (5) HVAC decontamination — critical because the duct system spreads smoke residue throughout the home.

The most important S700 insight for homeowners: "clean does not equal odor-free." A surface can look perfectly clean and still smell like smoke because volatile organic compounds (VOCs) have embedded into porous materials. Real S700 work always pairs cleaning with deodorization.

S700 identifies four major smoke residue types, each requiring different cleaning chemistry:

Wet smoke — Low-heat, smoldering, plastic and rubber fires. Sticky, smeary, very pungent. Hardest to remove because of low evaporation. Requires solvent-based cleaners and chemical sponges.

Dry smoke — Fast, high-heat, paper and wood fires. Powdery, less pungent, easier to clean but spreads further (lighter particles airborne longer). Cleaned with HEPA vacuum then dry chemical sponge.

Protein residue — Kitchen fires involving food. Practically invisible, but extreme odor. Coats surfaces in a thin film that requires specialty enzymatic cleaners and thorough deodorization.

Fuel-oil soot ("puff back") — Oil furnace malfunction, very fine sooty residue throughout the home via HVAC. Requires extensive HVAC decontamination plus surface cleaning.

An S700-compliant contractor identifies the residue type before specifying cleaning method. "Smoke is smoke" is not S700; it's amateur hour.

S700 prescribes a sequential cleaning approach. Skipping steps creates rework — and embedded odor that never fully leaves.

Step 1 — Stabilize and document. Emergency board-up of breached openings, tarping of compromised roof. Photo documentation of every affected surface for the insurance claim.

Step 2 — Remove gross soot. HEPA vacuum every horizontal and vertical surface in affected rooms. Removes 80%+ of loose soot before any wet chemistry.

Step 3 — Chemical sponging. Specialty dry chemical sponges lift residue without spreading it. Wet cleaning before chemical sponging actually drives soot deeper into materials.

Step 4 — Solvent or water-based wet cleaning. Surface-appropriate cleaner applied with controlled methods. Different chemistries for painted drywall, sealed wood, stained masonry, etc.

Step 5 — HVAC decontamination. Full duct cleaning, coil cleaning, blower-motor cleaning, filter replacement. If skipped, the system recontaminates the cleaned rooms every time it runs.

Step 6 — Contents pack-out (when needed). Soft goods (clothing, upholstery, bedding) packed and cleaned off-site at specialized facilities. Hard contents cleaned on-site or off-site as appropriate.

Step 7 — Deodorization. Thermal fogging, hydroxyl generators, or ozone treatment to neutralize embedded VOCs in framing, drywall, and porous materials.

Step 8 — Reconstruction. Drywall replacement where soot embedded, paint priming with sealant primers, finish paint. Separate phase from cleaning.

S700 covers three main deodorization technologies, each appropriate for different scenarios:

Thermal fogging — Heats a deodorizing solvent into a fog that penetrates the same micro-cracks that smoke originally entered. Considered the gold-standard for whole-room deodorization. Requires the space to be unoccupied during treatment.

Hydroxyl generation — UV-based device that produces hydroxyl radicals from ambient humidity. Neutralizes VOCs continuously, safe to run with occupants present. Slower than thermal fogging but no displacement required.

Ozone — Highly effective oxidizer. Powerful, but ozone is harmful to humans and pets — space must be evacuated for the duration and ventilated thoroughly afterward. Used selectively for stubborn residual odor.

Most professional fire jobs combine HEPA + chemical cleaning with thermal fogging or hydroxyl deodorization. The right combination depends on the residue type, the materials affected, and whether the home is occupied during restoration.

Smoke residue travels through HVAC ductwork during the fire and after. If the system runs at all during or after the loss (it almost always runs at least some), the ducts, coils, blower motor, and filters become reservoirs of smoke contamination.

S700 requires full HVAC decontamination as part of fire restoration. That means: physical inspection and cleaning of accessible ductwork, coil cleaning (often with HVAC contractor support), blower motor cleaning, complete filter replacement, and a post-cleaning test cycle to verify no residual odor migration.

If your fire restoration contractor doesn't include HVAC decontamination in their scope, the home will smell like smoke every time the heat or AC runs — for years. This is the single most commonly skipped step in budget fire restoration scopes. It's also the most commonly disputed item in fire insurance claims, because the homeowner can't see it but feels the effect.