Wildfire Pro Shop
Chemical Support
Equipment, technique, and strategy for protecting Tahoe’s defensible space — applied before the fire arrives.
Equipment selection, nozzle types, spray patterns, coverage levels, pump settings, calibration formulas, and firebreak strategies for CitroTech 31 — the EPA Safer Choice certified fire inhibitor for vegetation and defensible space.
Section 01
Product Overview & Physical Properties
CitroTech 31 is a water-based liquid fire inhibitor formulated with Tripotassium Citrate (TPC) as the primary active ingredient and Triethyl Citrate (TEC) as a coalescent agent. When applied and allowed to dry, water evaporates and leaves a thin, transparent potassium-salt crystalline coating on treated surfaces that interrupts the chemical chain reaction required for combustion. The product remains effective until rinsed or rained off.
CitroTech 31 is engineered with Triethyl Citrate (TEC) as its coalescent agent rather than natural gum. The patent notes that natural gum-based formulations tend to clog spray nozzles and require additional cleaning and maintenance. The TEC-based formula avoids this entirely, making it compatible with standard spray equipment without special maintenance.
Section 02
Delivery Equipment
CitroTech 31’s very low viscosity (5 cP — close to water at 1 cP) makes it compatible with a wide range of standard spray equipment. The core requirement is that the delivery system must be capable of atomizing the product to achieve proper surface coverage.
Backpack Spray-Atomizing System
The go-to tool for homeowners and crews treating defensible space by hand. Lightweight, precise, and ideal for spot treatment around structures, plantings, and tight perimeters.
Pressure Washer
Effective for treating structures, fences, decks, and adjacent vegetation. Provides good penetration into dense brush canopies at appropriate pressure settings.
Mobile Spray Tanker
For large-scale vegetation treatment along roadsides, utility corridors, and community defensible-space zones. Rapid coverage of extended linear perimeters.
Spray Atomizing Cannon
Breaks a pressurized stream into fine droplets directed over long distances. A cannon can create a buffer up to 300 feet deep on either side of a roadway, widening a freeway’s natural firebreak.
CitroTech 31 can be applied using mobile backpack atomizing systems, pressure washers, or any sprayer that will atomize the product. Its very low viscosity ensures free flow through standard spray equipment without modification.
Section 03
Application Technique & Spray Patterns
Proper technique ensures CitroTech 31 creates a continuous, effective fire-inhibiting barrier. The goal is complete surface coating of all combustible materials — including ground fuels beneath the canopy — down to mineral soil.
Apply Before Fire Arrives — Proactive Treatment Only
CitroTech 31 is a proactive pre-treatment, not an active suppression agent. Apply and allow to dry before a wildfire threatens. Once dry, the potassium-salt coating remains effective until rinsed or rained off. (Source: citrotech.com.)
Determine Perimeter Width — Minimum 2× Fuel Height
The treated perimeter must be at least twice the height of the fuel being treated. Example: 6-ft brush requires a minimum 12-ft treated band. For grasses, a 12-inch band is baseline — wider is always better. The widest portion should face the expected head of the fire.
Select Spray Pattern — Fog or Cone, Not Solid Stream
Set the nozzle to a wide fog, full-cone, or hollow-cone pattern. A solid stream produces runoff, wastes product, and disturbs the fuel bed without uniform coating. Use a flat-fan pattern for mobile-tanker boom applications.
Maintain 5–10% Spray-Pattern Overlap Between Passes
Keep a 5–10% overlap between passes for continuous coverage with no gaps — even narrow untreated gaps can let fire escape the line. For high-risk fuels (chaparral, heavy slash), favor the higher end of the range.
Saturate Until Dripping Wet
Apply generously until the surface is dripping wet. The spray must penetrate the canopy and coat dead ground fuels (leaves, needles, twigs, duff) down to the mineral soil layer.
Treat Ladder Fuels on Trees
For tall trees, spray a 20-ft perimeter around the base and treat the first 10 vertical feet of trunk and lower branches to eliminate ladder fuels that would let fire climb into the crown.
Calibrate Walking / Vehicle Speed to Coverage Level
Walking speed (backpack) or vehicle speed (tanker) must be calibrated against nozzle GPM to hit the target coverage level. Use the formula below to find your actual gallons per acre before starting. Keep vehicle speed under 10 mph. (Larimer County Sprayer Calibration Guide.)
Speed Calibration Formula
Calculate your actual application rate (Gallons Per Acre) from flow rate, travel speed, and swath width. Applies to both walking and vehicle applications. (Larimer County; University of Vermont Sprayer Calibration.)
495 = conversion constant (43,560 sq ft/acre ÷ 88 ft/min per 1 MPH)
MPH = travel speed (walking ≈ 2–3 MPH; vehicle ≤ 10 MPH)
W = effective swath width in feet
GPA = (0.5 × 495) ÷ (2 × 4) = 247.5 ÷ 8 = 30.9 GPA
Example — Mobile Tanker: GPM = 20 · Speed = 5 MPH · Swath = 10 ft
GPA = (20 × 495) ÷ (5 × 10) = 9,900 ÷ 50 = 198 GPA
Divide GPA by 435.6. Example: 198 GPA ÷ 435.6 = 0.45 gal/100 sq ft (Coverage Level 1–2 for grasses). To increase coverage, slow down or raise nozzle GPM; to decrease, speed up or reduce GPM.
Allow to Dry Completely Before Fire Threat
After application, allow CitroTech 31 to dry fully. As water evaporates, the potassium-salt coating forms on all treated surfaces. Drying time varies with temperature, humidity, and wind.
CitroTech 31 stays effective until rinsed or rained off. Inspect treated areas after any significant rainfall and reapply before the next fire-risk period. Frequency depends on local weather and risk level.
Section 04
Landscape Vegetation Application
CitroTech 31 is certified safe for plants, pets, and aquatic life (EPA Safer Choice; UL GREENGUARD Gold). Applying it correctly — targeting fire-prone tissues and avoiding unnecessary treatment of actively growing green material — protects sensitive vegetation, conserves product, and builds the most effective barrier.
Green, actively growing, well-irrigated vegetation has naturally high moisture content that resists ignition. The primary hazard in landscape plants is dead, dry, or woody material — not living green tissue. Per UC ANR, the three principles of defensible space are: (1) remove dead and dying material; (2) reduce vegetation density and ladder fuels; (3) replace hazardous vegetation with less-flammable, well-irrigated plants.
CitroTech 31 treats combustible surfaces so they resist ignition. Applied to already moist green foliage it offers minimal benefit — the same product on the dry, woody base and dead material of the same plant delivers far more protection per gallon.
Where to Spray on Landscape Plants
Base & Crown
The lowest 12–18 inches of trunk or main stems is the most critical zone — where ground-level fire and ember cast first make contact. Saturate the bark and woody tissue to dripping. Highest-priority zone on any shrub or tree.
Dead Branches & Dry Wood
Dead branches, dry twigs, and woody stems inside the canopy are primary ignition points. Apply directly, working outer edge inward. Don’t skip interior dead wood — it often catches first and carries fire into the canopy.
Bark & Exposed Wood
Tree bark, fence posts, wood mulch, and exposed wood adjacent to vegetation absorb the inhibitor and hold it in place. Spray thoroughly, especially on the fire-facing (upwind/uphill) side.
Ground Litter & Mulch
Dry leaf litter, pine needles, bark mulch, and dry grass under the plant are a critical ignition ladder. Treat the ground-fuel layer within a 3–5 ft radius of the base, saturating to dripping. UC ANR recommends litter no deeper than 3 inches.
Outer Canopy Edge
Where dead or dry foliage accumulates, embers ignite readily. Apply a light coat, focusing on visibly dry foliage. Full saturation of green, moist foliage isn’t needed — a light misting handles ember-cast protection.
Flowering & Green Interior Foliage
Active blooms and dense, well-irrigated green interior foliage are high-moisture and not primary ignition points. CitroTech 31 won’t harm them, but saturating them wastes product. Concentrate on base, dead wood, bark, and ground litter instead.
Recommended Plant Application Sequence
Clear dead branches, leaf litter deeper than 3 inches, and dry grass within 5 ft of the base. UC ANR lists removing dead/dying material as the first priority. This reduces fuel volume and lets product go further on what remains.
Start at the ground. Apply to the litter and mulch layer, working outward from the trunk in a circular pattern. Saturate to dripping — this prevents ground fire from reaching the base.
Apply directly to bark and woody tissue at the base, working around the full circumference. This is the highest-priority zone on the plant itself.
Direct the nozzle into the canopy interior. Use a narrow-angle nozzle (15–25° flat fan or solid stream) to reach interior dead wood without over-applying to surrounding green foliage.
Finish with a light coat on the outer canopy edge — especially the fire-facing side — to address ember-cast risk. Don’t saturate a full, moist canopy.
UC ANR recommends limbing mature trees to 6 ft. Where ladder fuels can’t be removed, treat the connecting material — low branches, tall shrubs under trees, and any woody bridge from ground to canopy.
Although CitroTech 31 is certified non-toxic to plants (EPA Safer Choice; UL GREENGUARD Gold), the following precautions apply to sensitive or edible vegetation:
- For ornamentals with known chemical sensitivity, test a small area 24 hours before full application and watch for discoloration or wilting.
- Avoid applying to plants in active bloom when pollinators are present — apply early morning or evening when activity is lowest.
- Don’t apply to stressed, drought-damaged, or diseased plants — irrigate before treatment if needed.
Section 05
Firebreak & Fireline Application Strategies
Choosing the right application pattern matters as much as the product itself. Strategy determines how effectively CitroTech 31 stops spread, protects structures, and establishes a defensible perimeter. The patterns below adapt recognized wildland-firefighting tactics for ground application.
Prioritizing perimeter containment over preserving interior fuels maximizes both effectiveness and personnel safety. Crews build defensible boundaries and, where appropriate, let fire do the work of fuel reduction within them.
Applying CitroTech 31 in a “#” pattern is a well-established wildland tactic known as “confine and contain” or “box and burn.” The intersecting lines create a series of containment boxes.
Strategic rationale:
- Perimeter control: retardant lines act as a barrier, preventing spread beyond the grid.
- Interior burnout: fire is allowed (often via intentional burnout) to consume fuels inside the lines, removing the hazard and widening the control line.
- Resource efficiency: instead of extinguishing every flame, crews build defensible boundaries and let fire reduce fuel within them — efficient at scale or with limited resources.
Application considerations:
- Line width: at least 1.5–2× the dominant fuel height (6-ft brush → ≥12-ft line).
- Fuel saturation: apply until dripping wet, down to mineral soil.
- Anchor points: tie the grid into roads, rivers, or rocky outcrops to strengthen containment.
Single Line (Wetline)
Lighter FuelsA single continuous line applied parallel to the advancing front or as a preparatory measure. Common in lighter fuels or as a temporary check line.
Best for: Lighter fuels, check lines, roadsides, property perimeters, prescribed-burn control lines, ridge-to-road breaks.
Key rule: Coat most or all readily burnable fuel; line must be wide enough to prevent radiation or spotting across it.
Double Parallel Line
Higher IntensityTwo parallel lines with a gap between them; the unburned fuel in the gap is intentionally ignited to create a wider, more robust break — useful against higher-intensity fire.
Best for: Higher-intensity situations, areas where a single line is insufficient, prescribed-burn perimeter reinforcement.
Perimeter Guard
Structure DefenseWhen the objective shifts to structure protection, apply a continuous ring around the structure, outbuildings, and critical infrastructure.
Best for: Homes, outbuildings, utility infrastructure, WUI assets.
Key rule: Protect outward from the base ~2× the surrounding fuel height.
Backing Fire / Anchor Line
Prescribed BurnsFor prescribed-burn support, establish a treated anchor line on the downwind side first — the most critical line, where slow backing fire eventually reaches the boundary.
Best for: Prescribed-burn perimeters, suppression support, reinforcing existing control lines.
Key rule: Apply to spotting-prone areas at 1/3–1/2 normal coverage; width depends on fuel, wind, and slope.
Ring & Spot Firing Support
Prescribed BurnsA ring of product can encircle a high-value resource (an endangered species or archaeological site) before the surrounding area is burned, or protect isolated hazards like a slash pile or dead snag.
Best for: Fire-sensitive trees, power poles, fences, outbuildings, archaeological sites within a burn perimeter.
Roadway Buffer / Corridor
Tanker / CannonTreat vegetation on both sides of a road to create a wide treated corridor. Roads are natural fuel breaks; CitroTech 31 extends their effective width significantly.
Best for: Pre-season community firebreaks, utility-corridor protection, freeway buffers.
Research confirms firebrand transport (spotting) — embers lofted by convection and landing beyond the line — is the primary way wildfires breach firebreaks, often traveling distances exceeding typical break widths. Product applied at 1/3–1/2 normal coverage downwind of the treated line can significantly reduce spotting-ignition risk. (Zong et al., “Effectiveness of Firebreaks: A Review,” Fire Ecology, 2026.)
Firebreaks placed along major fire paths and connected to other barriers (roads, rivers, ridgelines, rocky outcrops) protect better than isolated treatments. Applied along existing roads and natural features, CitroTech 31 reinforces them as control lines without clearing to bare soil. (Mollocana-Lara et al., 2025, in Zong et al., 2026.)
Section 06
Equipment Clean-Up & Maintenance
Prompt clean-up after use protects equipment longevity and prevents residue from affecting future applications.
Immediate Flushing
Thoroughly rinse tanks, hoses, nozzles, and internal pump parts with clean water right after use or at the end of each operational day to prevent scale buildup and clogging.
Nozzle & Hose Flush
Flush all nozzles and hose lines with clean water after each event. The TEC-based formula won’t clog nozzles, but residual product should still be flushed to prevent mineral buildup over time.
Section 07
Contact & Resources
| Resource | Details |
|---|---|
| Your Local Source | Wildfire Pro Shop — 889 Tahoe Blvd. Unit 1, Incline Village, NV 89451 |
| Phone | 909-519-5470 |
| Info@Wildfireproshop.com | |
| Website | wildfireproshop.com |
Specifications in this field guide are sourced from named, verifiable documents: citrotech.com; USFS Module 2 — Ground Delivery of Fire Chemicals; BLM Engine Operator Student Workbook (Jan. 2023); USDA Forest Service Wildland Fire Engine Guide (Oct. 2000); NWCG Firefighter Math; Larimer County Sprayer Calibration Guide; University of Vermont Sprayer Calibration; and Zong et al., “Effectiveness of Firebreaks: A Review,” Fire Ecology (2026).
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