Definitions

A

• Abrasive cleaning — A removal method that uses physical media or friction to wear away surface material along with contamination.

• Absorption — The process by which a material takes in laser energy rather than reflecting it.

• Access conditions — Physical layout factors that influence how easily a work area can be reached or prepared.

• Air filtration device (AFD) — Equipment used to control airborne particulates and maintain clean airflow in a work zone.

• Airflow requirements — The volume and quality of air needed to keep air‑cooled equipment operating within safe temperature limits.

• Alkaline cleaners — Chemical solutions formulated to break down organic residues, oils, and soot.

B

• Bonded contamination — Residues that have adhered strongly to a surface due to heat, chemical reaction, or prolonged exposure.

• Boundary controls — Physical or visual markers that define where work can occur and where access is restricted.

• Bright metal — Highly reflective metal surfaces that reflect a significant portion of incident energy.

C

• Carbon‑rich residue — Soot or smoke deposits with high carbon content, typically dark and absorptive.

• Char — Carbonized material formed when organic matter burns, often brittle and dark.

• Chemical shadowing — Discoloration or staining left behind when chemical cleaners interact unevenly with porous materials.

• Competent operator — A trained individual who performs work within the boundaries and controls defined by the Laser Safety Officer.

• Contamination level — The thickness, type, and severity of material present on a surface before cleaning.

• Controlled work area — A defined space where access, boundaries, and environmental conditions are managed for safety and consistency.

• Continuous‑wave (CW) laser — A laser that emits a constant, uninterrupted beam of energy.

• Corrosion — The chemical deterioration of metal caused by oxidation or environmental exposure.

• Coating failure — The breakdown or detachment of a paint or protective layer from a substrate.

D

• Demolition and rebuild — Removal and replacement of materials that cannot be restored.

• Dry soot — Powdery soot produced by low‑temperature or cellulose‑based fires.

• Dry‑ice blasting — A non‑abrasive cleaning method that uses frozen CO₂ pellets to remove contamination.

• Dust control — Measures taken to limit airborne particulates during cleaning or restoration work.

E

• Efflorescence — White, powdery mineral deposits that form when water evaporates from masonry surfaces.

• Encapsulation — Application of a coating or sealer to lock in residual staining or odor after cleaning.

• Environmental controls — Conditions managed to maintain safe and predictable work, such as airflow, temperature, and access.

• Exposure boundary — The defined perimeter within which laser energy may be present during operation.

F

• Focal distance — The distance between the laser lens and the surface, which affects energy density.

• Frequency (Hz) — The number of laser pulses delivered per second.

• Fuel‑based generator — A portable power source used to supply clean, stable electricity to equipment.

G

• Galvanometer system — A mechanism that moves the laser beam rapidly across a surface to create a scanning pattern.

• Graffiti coating — Pigmented material applied intentionally to a surface, often requiring specialized removal methods.

H

• HEPA vacuuming — High‑efficiency particulate air filtration used to remove loose soot or debris before further cleaning.

• Heritage material — Historically significant surfaces that require non‑destructive cleaning methods.

• High‑peak‑power pulse — A short burst of laser energy with high instantaneous power.

I

• IEC 60825‑1 — An international standard outlining safety requirements for laser equipment.

• IEC 60825‑14 — A standard providing guidance for safe laser use in workplaces.

• Inverter‑style generator — A generator that produces stable, clean electrical output suitable for sensitive equipment.

• Inspector‑friendly documentation — Records that clearly outline methods, controls, and conditions for review by materially interested parties.

L

• Laser Control Area (LCA) — A defined, restricted workspace where Class 4 laser operation occurs under controlled conditions.

• Laser Safety Officer (LSO) — The individual responsible for defining safety controls, boundaries, and documentation for Class 4 laser use.

• Light‑coloured contamination — Residues that reflect more energy and may require slower or more controlled removal.

• Line‑item — The selection of standardized estimating items in software such as Xactimate® to represent a scope of work.

M

• Material preservation — Retaining existing materials rather than removing or replacing them.

• Materially interested parties — Individuals or organizations with a direct financial or contractual interest in a project.

• Micro‑vaporization — Rapid heating of contamination that causes it to vaporize or ablate.

• Minimum setup fee — A baseline charge covering equipment transport, boundary setup, and initial site preparation.

• Mixed‑fuel fire residue — Soot produced by fires involving multiple fuel sources, often unpredictable in behavior.

• Moisture introduction — The addition of water or liquid during cleaning, which can affect porous materials.

O

• Odor encapsulation — Application of a coating designed to block residual odor after cleaning.

• Operator sweep speed — The manual rate at which an operator moves the laser head across a surface.

P

• Paint binder — The component of paint that holds pigment particles together and adheres them to a surface.

• Parameter control — Adjustment of settings such as power, frequency, and scanning speed to influence cleaning behavior.

• Porosity — The degree to which a material absorbs liquids or residues.

• Post‑treatment — Any coating, sealing, or finishing step applied after cleaning.

• Protein fire residue — Thin, sticky films produced by kitchen or food‑based fires.

• Pulse duration — The length of time each laser pulse lasts.

• Pulsed laser — A laser that emits energy in short, controlled bursts rather than a continuous beam.

R

• Reflectivity — The degree to which a surface reflects rather than absorbs energy.

• Repair‑over‑replacement — A restoration approach that prioritizes preserving existing materials when feasible.

• Residue thickness — The depth or density of contamination present on a surface.

• Runoff — Liquid waste produced during chemical or water‑based cleaning.

S

• Scanning speed — The programmed rate at which the laser beam moves across a surface.

• Secondary waste — Byproducts created during cleaning that require collection and disposal.

• Selectivity — The ability to target contamination while minimizing interaction with the underlying material.

• Shadowing — Visual discoloration left behind after incomplete or uneven cleaning.

• Shockwave lift — A microscopic pressure wave generated by a laser pulse that helps eject loosened material.

• Soot — Fine carbon particles produced by incomplete combustion.

• Spot size — The diameter of the laser beam where it contacts the surface.

• Standoff distance — The physical distance between the laser head and the surface.

• Standards‑aligned documentation — Records that reflect recognized safety and operational standards.

• Substrate — The underlying material being cleaned or restored.

• Substrate disturbance — Any alteration, removal, or degradation of the underlying material during cleaning.

• Synthetic fire residue — Oily, dark soot produced by burning plastics or polymers.

T

• Test area — A small, controlled section used to evaluate suitability and expected results before full‑scale work.

• Thermal conduction — Transfer of heat through a material.

• Thermal response — How a material reacts to heat or energy input.

• Thin‑film residue — A light, surface‑level deposit that may require specific removal methods.

V

• Vaporization threshold — The energy level at which a contaminant begins to vaporize.

• Variance reduction — Minimizing unpredictable cost or scope fluctuations through structured pricing and controls.

W

• Waste diversion — Reducing disposal volume by preserving materials that would otherwise be removed.

• Wet cleaning — Cleaning methods that rely on water, rinsing, or liquid solutions.