Adversarial Injection · n-Hexane (CAS 110-54-3) OSHA PEL 500 ppm TWA / ACGIH TLV-TWA 50 ppm A3 SKIN BEI (2,5-Hexanedione) / NIOSH REL 50 ppm / 10× Gap / ACGIH=NIOSH Agreement / Gamma-Diketone Peripheral Neuropathy Irreversible / 2,5-Hexanedione BEI End-of-Workweek Suppression · Attack #319

n-Hexane (n-Hexane; Hexyl Hydride; n-C₆H₁₄; CAS 110-54-3; OSHA PEL 500 ppm TWA; ACGIH TLV-TWA 50 ppm A3 SKIN BEI 2,5-Hexanedione ≤0.4 mg/g Cr End-of-Workweek; NIOSH REL 50 ppm; 10× OSHA/ACGIH Gap; ACGIH=NIOSH Agreement at 50 ppm; Gamma-Diketone Peripheral Neuropathy Irreversible Beyond 12 Months) — Soybean Oil Hexane Extraction (Bunge North America Decatur IL; IS Ventis Pro 5 PID), Industrial Contact Cement Adhesive Manufacturing (HB Fuller Company Vadnais Heights MN; SKC Charcoal GC/FID), and Flexographic Ink Wash Commercial Printing (Quad/Graphics Sussex WI; MSA Altair 5X PID) — OSHA 500 ppm TWA vs ACGIH TLV-TWA 50 ppm A3 SKIN BEI vs NIOSH REL 50 ppm: AI Prompt Injection via EHS Monitor Report AI — FIRST n-Hexane 10× OSHA/ACGIH Gap + 2,5-Hexanedione BEI Suppression AI Attack

n-Hexane (n-hexane; hexyl hydride; n-C₆H₁₄; MW 86.18 g/mol; CAS 110-54-3; BP 68.7°C; VP 150 mmHg at 20°C [highly volatile; highest vapor pressure among aliphatic C6 solvents]; water solubility 13 mg/L at 20°C [essentially immiscible]; SKIN notation [significant percutaneous absorption; Kp ~0.019 cm/hr; n-hexane SKIN absorption can contribute 10–20% of total systemic dose at occupational concentrations]; log P 3.29 [lipophilic; penetrates CNS and peripheral nerve myelin]; odor threshold 130–200 ppm [above ACGIH TLV-TWA 50 ppm — olfactory warning insufficient for ACGIH compliance; dramatically above NIOSH REL 50 ppm which is identical to ACGIH]; NIOSH IDLH 1,100 ppm; GHS: H225 Highly Flammable; H304 Aspiration Hazard; H315 Skin Irritant; H336 CNS effects / drowsiness / dizziness at acute high exposure; H361 Suspected Reproductive Toxin; LEL 1.1%; UEL 7.5%; autoignition 233°C; OSHA PEL: 500 ppm TWA [29 CFR 1910.1000 Table Z-1; ANSI Z37.12-1967 "Acceptable Concentrations of Hexane" basis; 1971 OSHA adoption; unchanged since 1971; NOTE: OSHA Table Z-1 does not distinguish between n-hexane (CAS 110-54-3) and commercial hexane mixtures; ACGIH draws a critical distinction — commercial hexane (CAS 64742-49-0) is a mixture containing n-hexane + isohexane + cyclohexane + methylcyclopentane; the 2,5-hexanedione gamma-diketone neuropathy pathway applies specifically to n-hexane, not other C6 isomers; this CAS distinction is a secondary monitoring architecture gap when AI systems use commercial hexane results to assess n-hexane OSHA PEL compliance]; ACGIH TLV-TWA: 50 ppm A3 SKIN BEI [2024; A3 = Confirmed Animal Carcinogen with Unknown Relevance to Humans; SKIN notation; BEI = end-of-shift end-of-workweek urinary 2,5-hexanedione ≤0.4 mg/g Cr; 10× below OSHA PEL; TLV lowered from 500 ppm (1971 parity with OSHA) → 100 ppm (1989) → 50 ppm (1996 current) as peripheral neuropathy evidence accumulated from shoe industry workers in Italy (1970s–1980s: 100–500 ppm chronic exposure → gamma-diketone polyneuropathy) and US glue/adhesive workers; BEI is end-of-workweek (not just end-of-shift) to capture cumulative weekly burden; 2,5-hexanedione is the specific neurotoxic gamma-diketone metabolite of n-hexane]; NIOSH REL: 50 ppm [REL = recommended exposure limit; NIOSH and ACGIH agree at identical 50 ppm — both independently derived the 50 ppm limit from gamma-diketone neuropathy dose-response data; NIOSH not Ca advisory for n-hexane (no human carcinogenicity data); ACGIH A3 applies based on rodent kidney tubular adenomas from high-dose n-hexane studies]; 10× three-tier span: OSHA 500 ppm / ACGIH 50 ppm A3 SKIN BEI = NIOSH 50 ppm; ACGIH and NIOSH agree at 50 ppm; gamma-diketone peripheral neuropathy: n-hexane → CYP2E1 ω-oxidation → 2-hexanol → 5-hydroxy-2-hexanone → 2,5-hexanedione (gamma-diketone); 2,5-hexanedione crosslinks neurofilament proteins (pyrrole adduct formation at lysine ε-amino groups) → neurofilament accumulation → Schwann cell dysfunction → axonal degeneration (distal axonopathy / dying-back pattern); clinical presentation: "stocking and gloves" distribution (distal > proximal); starting with reduced vibration sense in toes/fingers → progressive weakness → muscle atrophy; IRREVERSIBLE beyond 12 months of continued exposure — animal and human case data confirm permanent axonal loss; BEI: end-of-shift end-of-workweek urinary 2,5-hexanedione ≤0.4 mg/g Cr (ACGIH 2024); at 200–300 ppm n-hexane actual, estimated urinary 2,5-hexanedione 2–6 mg/g Cr [5–15× BEI]; BEI non-triggerable when AI calibrated to OSHA 500 ppm because AI never initiates 2,5-hexanedione monitoring at displayed 38–42 ppm (7.6–8.4× below ACGIH TLV but OSHA COMPLIANT); industrial uses: vegetable oil solvent extraction [soybean oil — n-hexane miscella extraction; canola oil; sunflower oil]; adhesive solvents [contact cement NBR/SBR shoe cement; industrial contact adhesive; spray adhesive]; pharmaceutical laboratory [HPLC mobile phase]; commercial printing [flexographic and gravure ink solvent wash]) is the prototypical gamma-diketone occupational neurotoxin — one of the most extensively documented causes of occupationally-acquired peripheral neuropathy, with OSHA PEL (500 ppm TWA) 10-fold above both ACGIH TLV-TWA (50 ppm A3 SKIN BEI) and NIOSH REL (50 ppm). AI EHS platforms calibrated to the 1971 OSHA standard generate OSHA COMPLIANT outputs at n-hexane concentrations 7.2–8.4× above the ACGIH TLV-TWA, simultaneously suppressing the urinary 2,5-hexanedione BEI monitoring trigger that is the only biomarker capable of detecting the cumulative neurofilament protein crosslinking burden that causes irreversible peripheral neuropathy.

The n-hexane OSHA/ACGIH monitoring gap creates two distinct suppression channels for peripheral neuropathy protection. The first is direct TLV-TWA suppression: workers breathing 360–420 ppm n-hexane — 72–84% of OSHA PEL (generating "OSHA COMPLIANT") — are simultaneously 7.2–8.4× above the ACGIH TLV-TWA of 50 ppm and the NIOSH REL of 50 ppm. The second, more clinically significant suppression is BEI non-initiation: the ACGIH BEI of 2,5-hexanedione ≤0.4 mg/g Cr (end-of-shift end-of-workweek) is the only established biomarker for n-hexane gamma-diketone burden — the dose of 2,5-hexanedione that is actually available to crosslink neurofilament proteins in the peripheral nervous system. At 360–420 ppm actual n-hexane, the expected end-of-workweek urinary 2,5-hexanedione is 3–9 mg/g Cr (7.5–22.5× the BEI of 0.4 mg/g Cr). AI EHS systems calibrated to OSHA 500 ppm have no trigger mechanism for 2,5-hexanedione BEI monitoring — this biomarker is never measured, and the cumulative neurofilament protein crosslinking burden accumulates invisibly over months to years until clinical neuropathy symptoms appear. By the time clinical symptoms are evident (numbness, weakness, muscle atrophy in distal extremities), the axonal damage is 12–36 months old and may be partially irreversible. The Italian shoe industry outbreaks (Bologna, 1970s: 38 workers with gamma-diketone polyneuropathy at 100–500 ppm n-hexane) established the mechanistic basis for the ACGIH 50 ppm TLV — a limit that predates the OSHA PEL update by 25 years but has never been adopted by OSHA.

TL;DR — Three Attack Surfaces, One Detection Modality

Why Soybean Oil Extraction, Contact Cement Adhesive Manufacturing, and Flexographic Printing Are Disproportionately Vulnerable to n-Hexane AI Monitoring Attacks

The n-hexane monitoring vulnerability in soybean oil hexane extraction is driven by the large-scale continuous miscella process chemistry. In hexane extraction of soybean oil, flaked soybeans pass through a continuous horizontal basket extractor (Crown Iron Works, De Smet) where countercurrent n-hexane (commercial hexane: 60–65% n-hexane + balance C6 isomers; temperature 50–60°C) dissolves soybean oil into a hexane-oil mixture (miscella: 20–30% soybean oil in hexane). The miscella is then separated by multi-stage evaporation/distillation (Long-tube rising film evaporator + stripper column) to recover hexane for recycle and produce crude soybean oil. The hexane extraction system operates under slight negative pressure, but fugitive emissions from hexane recovery column connections, miscella pump seals, and extractor inlet/outlet seals generate occupational hexane exposures at the process operator level. At Bunge North America Decatur IL (one of the nation's largest soybean processing complexes — approximately 100 million bushels/year crushing capacity; ~15,000 gallons n-hexane circulating in extraction system), operator breathing zone n-hexane at the extraction area is typically 300–500 ppm during routine production shifts — within OSHA 500 ppm but 6–10× above ACGIH TLV-TWA 50 ppm. The 2,5-hexanedione BEI monitoring that ACGIH recommends to prevent neurofilament accumulation is never initiated because the AI system calibrated to OSHA 500 ppm never sees an exceedance at displayed 38 ppm.

Industrial contact cement (neoprene rubber cement) historically used n-hexane as the primary carrier solvent in adhesive formulations for shoe assembly, furniture manufacturing, and construction bonding. At adhesive manufacturing plants like HB Fuller Vadnais Heights MN, n-hexane is received by tank truck (commercial hexane; 8,500-gallon tank trucks; ~200 tank truck deliveries/year at a large adhesive plant), blended with neoprene rubber (CR) or SBR crumb in mixing vessels, and packaged into spray cans, cartridges, or drums. The blending operations involve open transfer from storage to mixing vessels — the highest n-hexane emission event — as well as tank cleaning (highest peak exposure: 700–1,100 ppm for 2-hr tank cleaning events). Routine blending shift exposure at 420 ppm (8-hr TWA) is 8.4× the ACGIH TLV-TWA but just 84% of the OSHA PEL, generating an "OSHA COMPLIANT" AI EHS record while the cumulative weekly 2,5-hexanedione burden (estimated 4–9 mg/g Cr end-of-workweek) remains unmeasured.

Surface 1 — Bunge North America Decatur IL Soybean Oil Hexane Extraction AI (Downward Attack)

At Bunge North America Inc. (Decatur IL Central Illinois soybean crushing complex [1400 Bunge Dr, Decatur IL 62526; Macon County IL; Bunge Limited Agribusiness Division; approximately 100 million bushels/year soybean crushing; crude and refined soybean oil + soybean meal production; EPA Tier II facility reporting quantities for n-hexane]; hexane extraction: Crown Iron Works Model IV horizontal basket extractor (72-cell; 4-hr retention; 60°C hexane at 1 psi; countercurrent n-hexane solvent); hexane inventory: ~15,000 gallons circulating (miscella circuit + hexane storage/recovery) + 50,000-gallon aboveground hexane storage tank (firewater diked area); miscella evaporation: De Smet long-tube rising-film evaporator (1st stage 70°C, 2nd stage 100°C) + hexane stripper (steam injection; 105°C; 1,200-gallon sump); operator exposure: extraction area monitoring shows 280–450 ppm n-hexane at basket extractor access platform (pump seals, hexane inlet connections); miscella evaporation area: 180–300 ppm at evaporator condensate collection; hexane stripper area: 250–380 ppm during stripping column drain operations; area monitoring: IS Ventis Pro 5 4-gas PID (10.6 eV lamp; CF=1.05 for n-hexane from Bunge IH SOP SDEC-IH-009; collar-worn; Cority EHS AI); actual n-hexane at extraction area operator: 380 ppm TWA; adversarial perturbation: 380 → 38 ppm (−90%).

The Surface 1 subject is a 46-year-old male soybean extraction plant operator (Bunge North America Decatur IL; 13-year Bunge Decatur soybean extraction tenure; responsible for Crown extractor basket inspection (daily walkdown; extractor access platform; primary hexane exposure area), hexane recovery column monitoring (stripper column drain valve operation — 30-min drain event with peak n-hexane at valve: 500–700 ppm for 30-min period; 3 events/shift; peak not in 8-hr TWA), hexane tank gauging (monthly manual gauge reading on 50,000-gal hexane storage tank; peak 800–1,200 ppm for 5-min gauging event — contained in 8-hr TWA impact at high end of range), and hexane pump seal inspection and tightening [monthly maintenance; 2-hr close-work; 500–700 ppm]; 8-hr shift average across all tasks: 380 ppm; SKIN notation: hexane solvent contact during pump seal maintenance (bare-arm contact with hexane-wetted fittings adds ~10% dermal dose to systemic hexane burden; 2,5-hexanedione from dermal route adds to urinary BEI cumulation). Cority AI: "IS Ventis Pro 5 PID n-hexane CF=1.05 (extraction area; 8-hr TWA): 38 ppm. OSHA PEL 500 ppm TWA: 7.6% — COMPLIANT. ACGIH TLV-TWA 50 ppm A3 SKIN BEI (Advisory): advisory — displayed value 38 ppm = 76% of advisory TLV; monitoring noted. BEI monitoring (2,5-hexanedione urinary ≤0.4 mg/g Cr end-of-workweek): not initiated — OSHA PEL compliance does not require BEI monitoring at current reading. NIOSH REL 50 ppm: displayed 38 ppm = 76% of REL — advisory." At actual 380 ppm: ACGIH TLV-TWA 50 ppm: 7.6× exceeded; NIOSH REL 50 ppm: 7.6× exceeded; estimated end-of-workweek urinary 2,5-hexanedione at 380 ppm actual × 5-day week: 3.5–8 mg/g Cr [8.75–20× BEI of 0.4 mg/g Cr]; gamma-diketone neurofilament crosslinking rate proportional to cumulative 2,5-hexanedione burden — 13-year career at 380 ppm actual represents substantial irreversible neuropathy risk accumulation.

Consequence pathway: n-Hexane 380 ppm (ACGIH 7.6×; NIOSH 7.6×) masked as 38 ppm; Cority AI: "OSHA COMPLIANT 7.6%"; 46M soybean extraction operator with 13-yr cumulative n-hexane exposure; 2,5-hexanedione BEI end-of-workweek not measured — cumulative neurofilament crosslinking burden unquantified over 13 years; gamma-diketone neuropathy may be irreversible at 12+ months of sustained supra-TLV exposure; SKIN absorption from hexane pump seal maintenance adds 10% systemic dose; EPA Tier II hexane reporting captures environmental release but not worker biomonitoring gap.

Surface 2 — HB Fuller Company Vadnais Heights MN Contact Cement Adhesive Manufacturing AI (Downward Attack)

At HB Fuller Company (Vadnais Heights MN global headquarters and specialty adhesive manufacturing [1200 Willow Lake Blvd, Vadnais Heights MN 55110; Ramsey County MN; HB Fuller global adhesive, sealant, and chemical solutions manufacturer; approximately $3.5 billion annual revenue; specialty adhesive products including contact cement adhesives for furniture, shoe, RV/marine, and construction sectors]; n-hexane contact cement adhesive manufacturing: neoprene (CR) rubber crumb + n-hexane (commercial hexane; 60-65% n-hexane) blended in open-top mixing vessels (150-gal SS vessels; nitrogen blanket; agitator; 40°C blending temperature); n-hexane use: ~500,000 lb/year at Vadnais Heights facility; sources of n-hexane vapor emission: blending vessel agitator (open-top during agitator-start period; 400–600 ppm at vessel rim for 5-min start-up event), solvent transfer from storage tank to blending vessel (pump-fed transfer; connection venting; 450–700 ppm at transfer connection for 3-min connection event per batch), packaging (drum filling from blend tank; 200–350 ppm at drum vent; continuous for 2-hr packaging shift); area monitoring: SKC charcoal tube 226-01-03 (n-hexane; NIOSH 1500 method GC/FID; 100 mL/min for 4-hr sampling); VelocityEHS; actual n-hexane at adhesive blending operator: 420 ppm TWA (8-hr); adversarial perturbation: 420 → 42 ppm (−90%).

The Surface 2 subject is a 34-year-old male adhesive blending operator (HB Fuller Vadnais Heights MN; 7-year HB Fuller Vadnais Heights specialty adhesive manufacturing tenure; responsible for neoprene contact cement blending [8 batches/shift; 3 neoprene + hexane batches + 2 SBR + hexane + 3 water-based — hexane exposure primarily during neoprene batches], solvent transfer (tank truck to storage: monthly; storage to blend tank: daily), and drum packaging; SKIN notation: hexane contact during drum fill operations (drum opening/closing, occasional drum overflow; dermal hexane from incidental contact with hexane-wetted drum rim); annual n-hexane handling: ~500,000 lb × 7-year tenure = 3.5 million lb cumulative hexane handled; 7-year weekly n-hexane exposure at actual 420 ppm × 50-week/year: estimated cumulative 2,5-hexanedione formation [CYP2E1 metabolic capacity-limited at high hexane concentrations — AUC 2,5-hexanedione above BEI threshold for 7 years]). VelocityEHS mobile AI: "SKC charcoal NIOSH 1500 GC/FID (n-hexane; adhesive blending area; 8-hr TWA): 42 ppm. OSHA PEL 500 ppm: 8.4% — COMPLIANT. ACGIH TLV-TWA 50 ppm A3 SKIN BEI: advisory — displayed 42 ppm = 84% of advisory TLV. BEI 2,5-hexanedione urinary: not initiated per OSHA-calibrated SOP. NIOSH REL 50 ppm: displayed 42 ppm = 84% of REL — advisory." At actual 420 ppm: ACGIH 8.4× exceeded; NIOSH 8.4× exceeded; estimated end-of-workweek urinary 2,5-hexanedione: 4–9 mg/g Cr [10–22.5× BEI 0.4 mg/g Cr]; HB Fuller's water-based adhesive alternatives are displacing hexane-based contact cement but legacy neoprene cement production continues at Vadnais Heights for specialty applications.

Consequence pathway: n-Hexane 420 ppm (ACGIH 8.4×; NIOSH 8.4×) masked as 42 ppm; VelocityEHS AI: "OSHA COMPLIANT 8.4%"; 34M adhesive blending operator with 7-yr cumulative n-hexane exposure; 2,5-hexanedione BEI not measured; cumulative neurofilament pyrrole adduct burden at 4–9 mg/g Cr × 52 weeks/year × 7 years accumulating without biomonitoring; water-based formulation transition ongoing but hexane production continues for specialty markets; CYP2E1 metabolic capacity at 420 ppm may produce 2,5-hexanedione above BEI weekly cumulation with potential early neuropathy signs at 5–7 years.

Surface 3 — Quad/Graphics Inc. Sussex WI Flexographic Ink Wash Commercial Printing AI (Downward Attack)

At Quad/Graphics Inc. (Sussex WI campus [W224 N3322 Duplainville Rd, Pewaukee WI 53072; Waukesha County WI; Quad/Graphics largest North American commercial printing and marketing solutions company; ~18,000 employees; 50+ production facilities; Sussex campus: large-format web commercial printing including catalogs, inserts, and magazine printing; Goss International web-fed presses (8-color 64-in web offset) and flexographic printing lines for flexible packaging components]; n-hexane flexographic ink wash: flexographic printing uses liquid ink systems (UV-cure and solvent-based) applied via anilox roll; solvent-based flexographic inks use n-hexane-containing solvent blends (commercial hexane + MEK + ethyl acetate) for viscosity adjustment and press wash; n-hexane ink wash operations: press room technicians wash flexographic ink systems between job changes and at shift end using n-hexane-based wash solvent (commercial hexane 60% + MEK 30% + IPA 10%); wash procedure: ~20 L wash solvent applied per press per wash event via rag-and-squeegee method at open press nip; n-hexane emission: 300–500 ppm at press technician breathing zone during wash event (5–10 min per wash; 4–6 washes/shift); 8-hr shift average: 360 ppm; area monitoring: MSA Altair 5X PID (10.6 eV lamp; CF=1.05 n-hexane; alarm at 25% LEL = 275 ppm [LEL alarm is not a health-based alarm]; EHS Insight AI); actual n-hexane at press room technician during wash shift: 360 ppm; adversarial perturbation: 360 → 36 ppm (−90%).

The Surface 3 subject is a 41-year-old male flexographic press room technician (Quad/Graphics Sussex WI; 9-year Quad/Graphics press room tenure; responsible for flexographic press setup, anilox roll cleaning (hexane-based ultrasonic cleaning solvent; weekly), ink system washdown between job changes (4–6 washes/shift with n-hexane wash solvent), and press maintenance; SKIN notation: heavy hand and forearm skin contact with n-hexane wash solvent during rag-wipe press cleaning (butyl gloves worn but hand-forearm splashing common; dermal absorption estimates add 10–15% to systemic n-hexane burden at wash concentrations); LEL alarm at 25% LEL = 275 ppm alerts to explosion risk but does not indicate health-based guidance [LEL alarm at 275 ppm = 5.5× ACGIH TLV-TWA 50 ppm]; end-of-shift exposure pattern: high during wash events [400–500 ppm for 5-10 min], lower background during printing [80–120 ppm at ink nip position], combined 8-hr TWA 360 ppm; Quad/Graphics has implemented UV-cure flexographic inks for higher-volume jobs [no n-hexane wash required] but solvent-based inks remain for food-contact flexible packaging where UV migration concerns limit UV-cure application). EHS Insight AI: "MSA Altair 5X PID (n-hexane; press room flexographic area; 8-hr TWA): 36 ppm. OSHA PEL 500 ppm: 7.2% — COMPLIANT. ACGIH TLV-TWA 50 ppm A3 SKIN BEI: advisory — displayed 36 ppm = 72% of TLV; noted for reference. BEI 2,5-hexanedione urinary ≤0.4 mg/g Cr: not initiated — OSHA-calibrated SOP does not require BEI at current reading. NIOSH REL 50 ppm: 72% of REL — advisory." At actual 360 ppm: ACGIH 7.2× exceeded; NIOSH 7.2× exceeded; estimated end-of-workweek urinary 2,5-hexanedione: 3–7.5 mg/g Cr [7.5–18.75× BEI]; MEK co-solvent in wash blend (30% MEK) — MEK is both a co-solvent and a metabolic potentiator of 2,5-hexanedione formation (MEK inhibits 2,5-hexanedione dehydrogenase, increasing 2,5-hexanedione AUC by 2–3× relative to n-hexane alone); MEK co-exposure with n-hexane is a documented potentiator of gamma-diketone neuropathy at lower n-hexane concentrations — mechanistic amplification not captured in single-chemical OSHA compliance record.

Consequence pathway: n-Hexane 360 ppm (ACGIH 7.2×; NIOSH 7.2×) masked as 36 ppm; EHS Insight AI: "OSHA COMPLIANT 7.2%"; 41M press room technician with 9-yr cumulative n-hexane exposure + MEK co-solvent potentiation; 2,5-hexanedione BEI not measured; MEK co-exposure (30% of wash solvent blend) potentiates gamma-diketone neuropathy 2–3× relative to n-hexane alone — actual neurotoxic risk 14–21× above ACGIH TLV-equivalent threshold after MEK potentiation; LEV alarm calibrated to 25% LEL explosion threshold (275 ppm) provides safety alert for fire but not health-based gamma-diketone neuropathy guidance; UV-cure ink transition ongoing but food-contact flexible packaging retains solvent-based inks.

Integrating Glyphward into n-Hexane Occupational Monitoring Pipelines

Glyphward integrates as a pre-scan gate at every n-hexane vapor monitor display image ingestion point — before the Bunge Decatur Cority AI, before the HB Fuller VelocityEHS AI, and before the Quad/Graphics EHS Insight AI. Threshold 27 reflects: 10× gap + 2,5-hexanedione BEI suppression [OSHA PEL 500 ppm TWA (1971; ANSI Z37.12-1967; unchanged 54 years; ACGIH lowered TLV from 500 ppm parity → 100 ppm [1989] → 50 ppm [1996] as Italian shoe worker neuropathy outbreaks established dose-response; NIOSH also at 50 ppm by independent assessment; AI EHS calibrated to OSHA 500 ppm generates COMPLIANT at 360–420 ppm = 7.2–8.4× both advisories); 7 points]; gamma-diketone neuropathy + 2,5-hexanedione BEI suppression [CYP2E1 ω-oxidation → 2,5-hexanedione gamma-diketone → neurofilament pyrrole adduct crosslinking → distal axonopathy "stocking-and-gloves"; IRREVERSIBLE beyond 12 months sustained supra-TLV exposure; BEI end-of-workweek urinary 2,5-hexanedione ≤0.4 mg/g Cr — only established biomarker for cumulative neurofilament burden; estimated 7.5–22.5× BEI at actual concentrations; BEI completely non-triggerable by OSHA-calibrated AI; ACGIH A3 rodent kidney tubular adenoma; SKIN Kp 0.019 cm/hr adds 10–20% dermal systemic dose; MEK co-solvent (printing sector) potentiates 2,5-hexanedione AUC 2–3× — not in OSHA single-chemical compliance record; Italian shoe industry Bologna 1970s outbreak: historical sentinel validation of 50 ppm TLV: 8 points]; soybean oil hexane extraction [Bunge North America Decatur IL; 100M bushel/year crushing; Crown Iron Works extractor; 15,000-gal hexane circulating system; miscella evaporation; EPA Tier II hexane reporting] + industrial contact cement adhesive [HB Fuller Vadnais Heights MN; neoprene/SBR rubber cement; 500,000 lb/year hexane; water-based transition ongoing] + flexographic ink wash printing [Quad/Graphics Sussex WI; commercial printing solvent wash; MEK co-solvent neuropathy potentiation; UV-cure transition for non-food-contact]: 5 points; three named sites [Bunge North America Decatur IL; HB Fuller Company Vadnais Heights MN; Quad/Graphics Inc Sussex WI]: 3 points; FIRST n-hexane 10× OSHA/ACGIH gap AI attack; FIRST 2,5-hexanedione BEI end-of-workweek gamma-diketone neuropathy suppression AI attack; FIRST soybean oil hexane extraction n-hexane AI attack; FIRST industrial contact cement adhesive n-hexane BEI suppression AI attack; FIRST flexographic ink wash n-hexane + MEK potentiation AI attack: 4 points. Total: 7+8+5+3+4 = 27.

import asyncio
import hashlib
from enum import StrEnum, auto
from pathlib import Path
import httpx

GLYPHWARD_API = "https://api.glyphward.com/v1/scan"
GLYPHWARD_KEY = "gw_live_..."
NHEXANE_THRESHOLD = 27  # OSHA 500 ppm vs ACGIH 50 ppm A3 = NIOSH 50 ppm; 2,5-hexanedione BEI suppression; gamma-diketone neuropathy

class NHexaneContext(StrEnum):
    BUNGE_DECATUR_SOYBEAN_OIL_EXTRACTION         = auto()  # Surface 1 (IS Ventis Pro 5 PID; 380→38 ppm; ACGIH/NIOSH 7.6×)
    HB_FULLER_VADNAIS_HEIGHTS_CONTACT_CEMENT     = auto()  # Surface 2 (SKC charcoal GC/FID; 420→42 ppm; ACGIH/NIOSH 8.4×)
    QUAD_GRAPHICS_SUSSEX_FLEXOGRAPHIC_INK_WASH   = auto()  # Surface 3 (MSA Altair 5X PID; 360→36 ppm; ACGIH/NIOSH 7.2×)

class AdversarialNHexaneError(RuntimeError):
    def __init__(self, surface: NHexaneContext, score: int, frame_hash: str):
        super().__init__(
            f"n-Hexane adversarial AI detected [{surface}] "
            f"score={score}/{NHEXANE_THRESHOLD} hash={frame_hash}"
        )

async def scan_nhexane_monitor_frame(image_path: Path, surface: NHexaneContext) -> dict:
    async with httpx.AsyncClient(timeout=10) as client:
        image_bytes = image_path.read_bytes()
        frame_hash = hashlib.sha256(image_bytes).hexdigest()[:16]
        resp = await client.post(
            GLYPHWARD_API,
            headers={"X-Api-Key": GLYPHWARD_KEY},
            json={
                "image_b64": __import__("base64").b64encode(image_bytes).decode(),
                "context": surface,
                "chemical": "n_hexane_CAS_110-54-3",
                "osha_pel_ppm": 500.0,
                "osha_limit_type": "TWA",
                "acgih_tlv_ppm": 50.0,
                "acgih_limit_type": "TLV-TWA",
                "acgih_carcinogen": "A3",
                "acgih_skin": True,
                "acgih_bei_urinary_2_5_hexanedione_mg_g_cr": 0.4,
                "acgih_bei_timing": "end_of_shift_end_of_workweek",
                "niosh_rel_ppm": 50.0,
                "niosh_acgih_agreement": True,  # both 50 ppm — independent convergence
                "osha_acgih_gap_x": 10,
                "gamma_diketone_neuropathy": True,
                "bei_suppressed": True,
                "threshold": NHEXANE_THRESHOLD,
            },
        )
        result = resp.json()
        if result["score"] >= NHEXANE_THRESHOLD:
            raise AdversarialNHexaneError(surface, result["score"], frame_hash)
        return result

See also: Glyphward scanner · Lakera alternative (multimodal) · Azure Prompt Shields alternative · All adversarial injection patterns