DSS-Ch.05.01 — Bleach / Peroxide Shadowing

Bleach/peroxide shadowing is an appearance change caused by oxidizing agents (e.g., sodium hypochlorite bleach, hydrogen peroxide cleaners) contacting glass and drying/dwelling on the surface, sometimes in sunlight/heat. It presents as optical tone/contrast shift and, in stronger cases, very shallow, non-directional micro-texture within a spill/wipe footprint. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status. Treat fresh/unknown liquids per site safety.

• Irregular patches matching spill, spray, or wipe vectors, often near janitorial zones or façade-cleaning operations.
• Slight whitening or desaturation of reflections in specular view; under raking, interiors may read very fine modeled micro-texture (when concentrated or sun-baked).
• Edges are usually soft/feathered; overlap lines appear where multiple wipes ended.

Surface-catch class (MSRT)

• Commonly SC-0 (optical only).
• SC-1 (slight) can occur after concentrated or heated oxidizer dwell; SC-2 is rare.
• Perform one light, non-marring pass on a representative interior area; polymer stylus if a coating is suspected. MSRT supports classification only.

Visual signature

• Footprint-bounded tone shift with soft edges; interiors appear non-directional (not lineation).
• No chip-flank sparkle (not mechanical), no discrete fused nodules/pits (not hot-particle).

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, with normal incidence and oblique sweep (~60°-120°); use raking light macros to confirm presence/absence of micro-texture. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). If fixed parallax indicates a between-pane condition, classify CAT-5 by location (out of in-place scope) and refer.

Mechanism cue (context)

• Evidence of bleach/peroxide cleaners, sprayers, janitorial carts, or pressure-washing with oxidizing additives; note sun exposure/dwell time.

Assign CAT by appearance + MSRT + morphology (three-part cueing). Depth/relief values are indicative-field measurement not required.

• CAT-1 (Benign / non-relief): Optical tone/contrast shift only, SC-0; visible mainly at certain angles or in raking; minimal impact at standard view. Indicative relief: 0-10 μm (optical).
• CAT-2 (Light): Very shallow modeled micro-texture, SC-1, confined to spill/wipe footprint; limited impact at standard view. Indicative relief: ~10-40 μm.
• CAT-3 (Moderate): Broader matte/whitened footprint legible at standard distance; SC-1 to SC-2. Indicative relief: ~40-120 μm.
• CAT-4 (Severe): Uncommon for oxidizers alone; if pronounced matte fields or wide-area whitening are present, consider mixed chemistry (alkaline/oxidizer stack) and re-evaluate under applicable DSS. Indicative relief: ~120-300 μm+.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators (active cracks/pane movement), or confirmed functional-coating loss on the surface to be worked → CAT-5.

CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not “probe” with MSRT.

• vs. Degreaser/alkaline burn (Ch.04.03): Alkaline burn shows grainier micro-texture with sheet/run geometries; oxidizer shadowing tends to be softer, optical with SC-0 to SC-1.
• vs. Adhesive remover staining (Ch.04.02): Adhesive remover exhibits wipe directionality + overlap lines centered on label sites; oxidizer footprints may be broader sprays or mop wipes.
• vs. Mineral staining/etch (Ch.03): Mineral conditions follow spray arcs/rings/runs and often yield ring halos; oxidizer shadowing lacks mineral ring morphology.
• vs. Solvent bloom (Ch.04.01): Solvent bloom can present similar matting but is linked to paint removal context; cross-check site operations.
• vs. Coating anomalies (Co-family): Coating rub/patchiness gives sheen/color shift but lacks chemical exposure context; on a worked coated surface any anomaly is not permitted at acceptance (VIS §6.2.e).

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; include raking macros of footprint interior and edges; add context frames (cleaners, carts, work area). Record distance/angle in-frame.
• MSRT result: One light, non-marring pass on footprint interior; record SC-class (SC-0/SC-1/SC-2). Polymer stylus if coating is suspected.
• Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e.

• Ch.05.01 Bleach / Peroxide Shadowing - Footprint-bounded tone/whitening on surface #___ with [SC-0/SC-1/SC-2], visible at [12/36/72 in] under VIS geometry after Non-Invasive Reveal. Morphology: soft edges, non-directional interior, no chip-flank sparkle, no discrete pepper. Classification: CAT-[1/2/3/4] by relief/visibility; CAT-5 if between-pane, integrity cues, or coating-side loss on the surface to be worked. Forms + photo set completed; acceptance per VIS-A §6 (separate).