H2S Scavengers, LEL Scavengers & Degassing Chemistry
Shutdown & Turnaround Chemistry
Fast, irreversible scavenging for safe vessel entry. Complete chemical degassing programs combining H2S scavengers, LEL scavengers, iron sulfide dissolvers, and vapor suppression chemistry. Named products. Published procedures. Proven in the field.
Fast & Irreversible | H2S + LEL + FeS | Published Case Studies | BrightShield™ Programs
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What Happens When You Request a Recommendation
A Guardian industrial cleaning specialist will contact you to understand your application, your deposit, and your cleaning challenges.
Our team will review your deposit, surface, and operating conditions — and if needed, our lab will test your soil to identify the most effective chemistry.
We’ll provide a product recommendation, application guidance, and a quote — with no obligation to proceed.
If the solution makes sense for your operation, we’ll arrange supply, provide application training, and support you from day one.
Why Chemistry Selection Matters for Shutdowns & Turnarounds
Every hour of turnaround downtime costs money. Every entry into a confined space carries risk. The chemistry you choose for degassing, scavenging, and decontamination directly affects both.
The right chemistry scavenges H2S fast and irreversibly, suppresses hydrocarbon vapors to prevent LEL cycling, dissolves pyrophoric iron sulfide without releasing H2S, and cleans as it degasses. The wrong chemistry cycles LEL levels, leaves residual H2S, or creates secondary hazards that delay safe entry.
Guardian’s approach: chemistry + procedure + monitoring. We don’t just supply chemicals—we design complete degassing programs that protect your people and your schedule.
H2S Scavengers — Fast, Irreversible Hydrogen Sulfide Removal
Hydrogen sulfide (H2S) is one of the most dangerous gases encountered in industrial operations — toxic, flammable, and corrosive. Effective scavenging requires chemistry that reacts with H2S fast, irreversibly, and without producing secondary hazards.
Guardian’s Sourguard series scavengers are designed for exactly this. They convert H2S to a liquid product. The Sourguard series is unaffected by CO2 and has been proven to reduce mercaptan levels by over 90%.
Sourguard SG: Concentrated H2S scavenger. Fast, irreversible. Not winterized (warm-season use).
Sourguard DSS: High-strength H2S and mercaptan scavenger. Winterized for year-round use. >90% mercaptan reduction.
LEL Scavengers & Vapor Suppression — Reduce Explosive Risk, Accelerate Safe Entry
LEL scavengers are surfactant-based chemicals that suppress hydrocarbon vapors by emulsifying them — binding volatile hydrocarbons in the liquid phase so they can’t re-enter the gas phase. This dual functionality (vapor reduction + liquid hydrocarbon emulsification) prevents LEL cycling, which is the most common failure mode in conventional degassing.
Guardian’s Purge series offers two options depending on your application:
Purge C: Low-foam LEL scavenger. Chemical encapsulation of hydrocarbons in both liquid and vapor forms. Prevents LEL cycling. Can scavenge low levels of H2S. Easy to apply and circulate with hot or cold water.
Purge HF: High-foam LEL scavenger + cleaner. Scavenges LEL and low levels of H2S. Maximum emulsification capacity for effective surface cleaning during degassing. Effective benzene vapor removal. A single-component solution for many degassing applications.
Learn more: “Improve Safety and Speed in Your Shutdown with LEL Scavenging”
Iron Sulfide Dissolution — Non-Oxidizing Chemistry for Pyrophoric Control
Iron sulfide (FeS) is pyrophoric — it can spontaneously ignite when exposed to air. It also generates toxic H2S gas when dissolved with oxidizing chemicals. This makes iron sulfide one of the most dangerous deposits encountered during shutdowns and turnarounds.
Guardian’s Ferrosol series dissolves iron sulfide using a non-oxidizing chelation process. The iron sulfide forms a stable, water-soluble complex that does not release H2S and will not cause re-deposition or water injection problems downstream.
Ferrosol: Winterized, non-oxidizing iron sulfide dissolver. No H2S outgassing during dissolution. Stable water-soluble complex. No re-deposition. Compatible with Guardian’s H2S and LEL scavengers for combined programs.
Ferrosol SG: Summer-grade, non-oxidizing iron sulfide dissolver. No H2S outgassing during dissolution. Stable water-soluble complex. No re-deposition. Compatible with Guardian’s H2S and LEL scavengers for combined programs.
The BrightShield™ Process — Complete Chemical Degassing Programs
Guardian doesn’t just supply chemicals — we design complete degassing programs that combine the right chemistry, application procedures, and on-site monitoring to protect your people and your schedule.
The BrightShield process brings together:
- H2S scavenging (Sourguard series)
- LEL/VOC scavenging and vapor suppression (Purge C or Purge HF)
- Iron sulfide dissolution (Ferrosol)
- Sludge dispersion and surface cleaning (Hydrosol)
- Application procedures tailored to your equipment and contaminants
- On-site monitoring to confirm safe conditions before entry
Case Study: At a large Alberta hydrocarbon processing facility, the BrightShield process was used to safely remove 700 m³ of sludge from a storage tank containing H2S, iron sulfides, mercaptans, LEL vapors, and benzene. All fluids were treated, all vapors were controlled, and all waste was disposed of in compliance with regional regulations.
Read the full case study: “From Hazard to Handled: How Chemical Tank Cleaning Eliminated Sludge and Reduced Toxic Gas Concentrations.”
Complete Chemistry for Every Shutdown Challenge
From H2S scavenging to pyrophoric control, Guardian supplies the full spectrum of shutdown and turnaround chemistry — backed by published procedures and field support.
H2S Scavenging
LEL Scavenging & Vapor Suppression
Iron Sulfide Dissolution
Vapor Phase Cleaning
BrightShield™ Programs
Tank & Vessel Cleaning
What Sets Guardian Apart
Finding the right chemistry is only part of the equation. Here’s why 4,000+ clients trust Guardian to get it right.
Complete Chemistry from One Supplier
H2S scavengers, LEL scavengers, iron sulfide dissolvers, vapor suppression, and cleaning chemistry — all from one supplier. One call, one program, no coordination gaps.
Published Procedures & Case Studies
We don’t just ship totes. We provide application procedures, concentration guidance, and published case studies showing real-world outcomes.
Fast, Irreversible Scavenging
Our Sourguard H2S scavengers react fast and irreversibly. Our Purge LEL scavengers prevent vapor cycling through dual-functionality emulsification.
Field-Proven Across North America
65+ years of industrial chemistry. Published case studies in Alberta refineries. Winterized formulations for year-round operations. Field support when and where you need it.
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Cleaning & Degreasing Case Studies
Request a Quote or Technical Consultation
Planning a shutdown or turnaround? Tell us about your contaminants, equipment, and timeline — and a Guardian degassing specialist will design a program for your operation. Most responses within one business day.
Frequently Asked Questions about Bitumen Removal and Heavy Equipment Cleaning Chemicals
An H2S scavenger is a chemical that reacts with hydrogen sulfide gas to convert it into a stable compound. Effective H2S scavengers react fast and irreversibly — meaning the H2S cannot be released again. Guardian’s Sourguard series is concentrated, irreversible, and unaffected by CO2.
LEL scavenging uses surfactant-based chemicals to suppress flammable hydrocarbon vapors below the Lower Explosive Limit. LEL scavengers work by emulsifying hydrocarbons in both liquid and vapor forms, preventing dangerous vapor cycling. Guardian’s Purge C and Purge HF are dual-functionality LEL scavengers.
LEL scavengers contact hydrocarbon vapors through spraying, steaming, or circulation. They emulsify (encapsulate) the hydrocarbon molecules, binding them in the liquid phase so they can’t re-enter the gas phase. This dual functionality — reducing vapors and eliminating their liquid source — prevents LEL cycling.
Iron sulfide (FeS) forms when H2S reacts with iron in process equipment. FeS is pyrophoric — it can spontaneously ignite on air exposure. Dissolving it with oxidizing chemicals releases toxic H2S. Non-oxidizing dissolvers like Ferrosol dissolve FeS into a stable, water-soluble complex without releasing H2S.
Yes. Combining them is often the safest and most efficient approach. Guardian’s BrightShield programs use Sourguard, Purge, and Ferrosol together with tailored procedures for each application.
Tank degassing typically uses LEL scavengers (vapor suppression), H2S scavengers (hydrogen sulfide neutralization), and iron sulfide dissolvers (pyrophoric removal). The specific chemistry and application methods depend on the contaminants present.
BrightShield is Guardian’s complete chemical degassing program. It combines H2S scavenging (Sourguard), LEL/VOC scavenging (Purge), iron sulfide dissolution (Ferrosol), and surface cleaning (Detrax) with application procedures and on-site monitoring tailored to each situation.
Planning a Shutdown or Turnaround?
Talk to our degassing specialists to design a chemical program that protects your people and your schedule.
