Prompt injection in polycarbonate PC BPA interfacial phosgenation Makrolon Lexan AI

Three adversarial injection surfaces in polycarbonate PC BPA phosgenation AI

1. Phosgene feed rate to BPA phosgenation reactor display AI (Emerson Micro Motion CMFS015M / Endress+Hauser Promass 83E / Brooks Instrument SLAMf Coriolis mass flow display AI — rendered DCS COCl₂ feed rate display AI classifying phosgene flow against the design COCl₂:BPA molar ratio — 105th upward attack; FIRST polycarbonate PC production AI attack; FIRST BPA phosgenation AI attack; FIRST Makrolon Lexan polymer production AI attack; FIRST safety-critical polymer MW control AI attack; FIRST DCM 1910.1052 carcinogen surface AI attack)

The phosgene (COCl₂) feed rate to the BPA interfacial phosgenation reactor is the primary determinant of polycarbonate molecular weight and the completeness of BPA conversion to PC oligomers and high-MW polymer. The design COCl₂:BPA molar ratio is approximately 2.05:1 (slightly above the stoichiometric 2:1 to ensure complete BPA phosgenation; at 2.05:1, >99.9% BPA is converted to carbonate linkages with essentially no residual BPA phenolate remaining in the product). At a 100,000 t/yr PC plant (Makrolon 2807 GP grade; Mw 27,000 g/mol; design phosgene consumption approximately 900–950 kg/hr COCl₂), the Coriolis mass flow meter (Emerson Micro Motion CMFS015M; accuracy ±0.1% of reading; SIL 2 certified; 4–20 mA HART output) measures the COCl₂ feed flow continuously and controls the phosgene control valve to maintain the design molar ratio relative to the BPA feed (measured by a companion BPA solution Coriolis meter). The AI monitoring system processes rendered DCS display images of the phosgene feed Coriolis meter display to classify: 900–980 kg/hr (normal; adequate phosgene), 750–900 kg/hr (reduced; investigate phosgene supply; adjust control valve), below 750 kg/hr (alarm; phosgene supply disruption; consider production rate reduction). Display range: 0–1,200 kg/hr COCl₂, 200 px, 0.167 px/(kg/hr).

An adversarial ±8 DN upward pixel perturbation targeting the phosgene feed rate display shifts the apparent flow from the dangerous actual value to a normal displayed value: actual COCl₂ flow 380 kg/hr (phosgene vaporiser HV-301 pressure regulator spring failure; vaporiser outlet pressure dropped from design 8 bar to 2.8 bar; COCl₂ feed flow reduced from 940 to 380 kg/hr over 40 minutes; temperature in the interfacial reactor and in the COCl₂ dissolving tank are within normal range, masking the supply disruption from temperature-based alarms) corresponds to 380 × 0.167 = 63.5 px ≈ 64 px on the 0–1,200 kg/hr, 200 px, 0.167 px/(kg/hr) display. The normal displayed value of 940 kg/hr corresponds to 940 × 0.167 = 157 px. The ±8 DN upward attack shifts the pixel region from 64 px to 157 px; the AI reads 157 px ÷ 0.167 px/(kg/hr) = 940 kg/hr — normal operating rate; no action. At actual 380 kg/hr COCl₂ (vs design 940 kg/hr), the COCl₂:BPA molar ratio drops from design 2.05:1 to 380/940 × 2.05 = 0.83:1 — below the stoichiometric 1:1 minimum. Below stoichiometric: the BPA-diphenolate anions in the aqueous NaOH phase are not fully converted at the biphasic interface; PC chains formed are predominantly low-MW oligomers (the chain growth mechanism requires progressive carbonate linkage formation, which slows dramatically when COCl₂ is limiting; Flory-Schulz chain-length distribution shifts to lower Mw). The resulting PC from 380 kg/hr COCl₂ production: Mw 4,000–8,000 g/mol (vs specification 25,000–35,000 g/mol). This off-spec PC passes visual inspection identically to in-spec PC — both are clear, colourless transparent solids — but is mechanically deficient. Notched Izod impact strength drops from spec ≥750 J/m (standard Makrolon 2807) to approximately 25 J/m (low-Mw PC oligomer blend; a 30-fold decrease). If this off-spec PC is used in bulletproof glazing (NIJ 0108.01 Level III; 5-ply PC laminate; each ply requires Mw >22,000 g/mol for penetration resistance at the 7.62 mm NATO round at 838 m/s threat): the glazing fails the NIJ Level III test — the round penetrates rather than being stopped by plastic deformation of the PC plies. If used in FAR 25.775 aircraft cabin windows: the bird-strike test (230 g bird at 160 kt = approximately 340 J impact energy) shatters the low-Mw PC window rather than causing elastic deformation — a cabin window failure during flight. This is the 105th upward-direction attack in the Glyphward adversarial industrial AI portfolio. Free tier — 10 scans/day, no card required.

2. Chain terminator p-tert-butylphenol (p-TBP) feed rate display AI (Endress+Hauser Proline Promag 50 / Yokogawa ADMAG AXF / Siemens SITRANS F electromagnetic flow meter display AI — rendered DCS p-TBP solution feed rate display AI classifying chain terminator dosing against the design 10–12 L/hr range for target PC Mw 25,000–35,000 g/mol)

p-tert-Butylphenol (p-TBP; CAS 98-54-4; MW 150.22 g/mol; a monohydric phenol that terminates PC chain growth by capping the growing carbonate chain end as a p-TBP carbonate ester that cannot react further with BPA; chain terminator concentration determines final PC molecular weight by the Carothers equation: Mw ∝ 1/[p-TBP mol fraction]) is fed as a 0.5–2 wt% solution in DCM at 10–12 L/hr (design; corresponding to 0.5–2.0 mol% p-TBP relative to BPA feed; this range produces PC Mw 25,000–35,000 g/mol at design COCl₂:BPA ratio). The p-TBP solution feed is measured by an electromagnetic flow meter (Endress+Hauser Proline Promag 50; Yokogawa ADMAG AXF; Siemens SITRANS F MAG; suitable for the DCM solvent — though electromagnetic meters require conductive liquids; the 0.5–2 wt% p-TBP/DCM solution is supplemented with a trace electrolyte additive for conductivity). The AI monitoring system processes rendered DCS display images of the p-TBP flow meter display to classify: 10–12 L/hr (normal; target Mw range achieved), 7–10 L/hr (slightly elevated Mw; acceptable; investigate terminator pump), below 7 L/hr (alarm; chain terminator insufficient; Mw drifting high; risk of ultra-high Mw gel formation). Display range: 0–20 L/hr p-TBP solution feed, 200 px, 10 px/(L/hr).

An adversarial downward pixel perturbation targeting the p-TBP feed rate display shifts the apparent flow from the dangerously low actual value to a normal displayed value: actual p-TBP flow 0.8 L/hr (p-TBP solution metering pump MP-117 check valve failure on discharge side; back-flow to supply tank over 2 hours reduced effective p-TBP delivery from design 11 L/hr to 0.8 L/hr; the DCM solution itself continues to flow at design rate, giving effectively zero p-TBP concentration in the phosgenation reactor) corresponds to 0.8 × 10 = 8 px on the 0–20 L/hr, 200 px, 10 px/(L/hr) display. The normal displayed value of 11.6 L/hr corresponds to 11.6 × 10 = 116 px. The adversarial downward attack shifts the pixel region from 8 px to 116 px; the AI reads 116 px ÷ 10 px/(L/hr) = 11.6 L/hr — normal terminator rate; no action. At actual 0.8 L/hr p-TBP vs design 10–12 L/hr: chain terminator is nearly absent from the BPA phosgenation reactor. With effectively zero chain terminator, PC chain growth is limited only by stoichiometry and reactor residence time; the BPA-phosgene polymer grows to very high molecular weight: Mw exceeding 150,000 g/mol (a 5- to 6-fold increase above specification). Ultra-high Mw PC (Mw >150,000): melt viscosity at processing temperature 300°C is >30,000 Pa·s (vs specification for Makrolon 2807: <2,000 Pa·s at 300°C); at >30,000 Pa·s, the PC melt cannot be processed on standard injection moulding machines or extrusion lines — the extruder torque limit is exceeded (torque alarm triggers extruder shutdown) within minutes of high-Mw PC entering the pelletising extruder. The ultra-high Mw PC batch — potentially 200–500 tonnes produced during the period of the adversarial attack — must be reprocessed or scrapped, representing a production loss at current PC market prices of approximately EUR 1.2–3.0 million per event. The production line shutdown initiated by the extruder torque alarm also disrupts the downstream PC compounding operations, creating a cascade effect through the supply chain for Makrolon optical, automotive, and medical grade customers.

3. DCM methylene chloride vapour scrubber outlet concentration display AI (Servomex 4900 / Emerson X-STREAM / ABB EL3020 DCM vapour analyser display AI — rendered DCS activated-carbon scrubber outlet DCM concentration display AI classifying DCM against the OSHA PEL 25 ppm TWA threshold requiring medical surveillance and biological monitoring)

Methylene chloride (DCM; CH₂Cl₂; MW 84.93 g/mol; BP 39.6°C; vapour pressure at 20°C 400 mmHg = 526,000 ppm; OSHA PEL 25 ppm TWA per 29 CFR 1910.1052; OSHA STEL 125 ppm; OSHA Action Level 12.5 ppm; NIOSH carcinogen Ca — no safe level established; IARC Group 2A probable human carcinogen; OSHA 1910.1052 medical surveillance triggered at AL 12.5 ppm; biological monitoring endpoint: carboxyhemoglobin COHb <3.5% at end of shift) is the primary solvent in the interfacial BPA/phosgene polycondensation organic phase. The PC production plant emits DCM vapour from the reaction vessel, the phase separation stage, the PC solvent-recovery distillation column, and the PC precipitation/pelletising stage; these emissions are collected in an activated-carbon bed scrubber (adsorption bed; periodic steam regeneration; design inlet DCM: 200–500 ppm; design outlet DCM: <10 ppm before discharge to facility exhaust). The outlet DCM concentration is monitored continuously by an online infrared analyser (Servomex 4900; Emerson X-STREAM Enhanced; ABB EL3020; sensitivity 0.1 ppm DCM; range 0–500 ppm; NDIR detection at 1,267 cm⁻¹ CH₂Cl₂ stretching mode). The AI monitoring system processes rendered DCS display images of the scrubber outlet analyser to classify: <10 ppm (scrubber working; discharge compliant), 10–25 ppm (approaching PEL; monitor frequency increased; prepare for carbon bed changeout), >25 ppm (scrubber breakthrough; OSHA PEL exceeded; initiate carbon bed changeout; increase ventilation). Display range: 0–500 ppm DCM, 200 px, 0.4 px/ppm.

An adversarial downward pixel perturbation targeting the DCM scrubber outlet display shifts the apparent DCM concentration from the dangerous actual value to a compliant displayed value: actual DCM 318 ppm (activated-carbon bed carbon 3A saturated after 72 hours of continuous operation at above-design DCM loading from an upstream DCM recovery condenser operating at reduced cooling water temperature; the bed has reached breakthrough — carbon adsorption capacity exhausted; DCM passes through the bed to the outlet and facility exhaust) corresponds to 318 × 0.4 = 127.2 px ≈ 127 px on the 0–500 ppm, 200 px, 0.4 px/ppm display. The compliant displayed value of 11 ppm corresponds to 11 × 0.4 = 4.4 px ≈ 4 px. The adversarial downward attack shifts the pixel region from 127 px to 4 px; the AI reads 4 px ÷ 0.4 px/ppm = 11 ppm — below the OSHA Action Level; no medical surveillance triggered; carbon bed changeout not initiated. At 318 ppm DCM in the facility exhaust (12.7× the OSHA PEL 25 ppm TWA): workers in the area surrounding the exhaust discharge (maintenance workers on the scrubber platform, operating personnel on the PC product dryer catwalk) are exposed to DCM at 318 ppm for the duration of the 8-hour shift. DCM is metabolised by the liver CYP2E1 enzyme to formaldehyde and CO; at 318 ppm DCM for an 8-hour shift, equilibrium COHb rises to approximately 20–25% (NIOSH ACGIH pharmacokinetic model). Symptoms of 20–25% COHb: headache, dizziness, fatigue, impaired cognitive function and judgment — all symptoms the worker may attribute to shift fatigue, heat, or the normal work environment of a chemical plant, since no CO alarm is present (the CO source is internal CYP2E1 metabolism, not an ambient CO leak) and the DCM alarm at the scrubber outlet is suppressed by the adversarial attack. The 24–48 hour lag of OSHA-required biological monitoring (COHb measurement at end of shift; lab result turnaround 1–2 days) means the worker can receive multiple 8-hour shifts of 20–25% COHb exposure before the biological monitoring data returns and corrective action is taken — a cumulative carboxyhemoglobin exposure that risks lasting cardiovascular and neurological effects. Free tier — 10 scans/day, no card required.

Integration: polycarbonate PC BPA phosgenation AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate at every rendered-image ingestion boundary in the polycarbonate PC BPA interfacial phosgenation AI monitoring pipeline — before the phosgene feed rate AI processes rendered Emerson Micro Motion CMFS015M / Endress+Hauser Promass 83E / Brooks Instrument SLAMf Coriolis mass flow display images, before the p-TBP chain terminator AI processes rendered Endress+Hauser Proline Promag 50 / Yokogawa ADMAG AXF / Siemens SITRANS F electromagnetic flow meter display images, and before the DCM scrubber outlet AI processes rendered Servomex 4900 / Emerson X-STREAM / ABB EL3020 vapour analyser display images. Threshold 43 for PC BPA phosgenation AI reflects: OSHA PSM phosgene TQ 500 lbs (every PC plant is PSM-covered by the phosgene requirement alone); phosgene as a WWI chemical weapon with NIOSH IDLH 2 ppm; safety-critical polymer applications (aircraft cabin windows, bulletproof glazing, medical device housings) where Mw deficiency from the phosgene feed attack creates a delayed multi-month consequence pathway; DCM IARC Group 2A carcinogen with the CYP2E1 CO-poisoning mechanism producing COHb poisoning without any conventional CO source; and the 105th upward attack milestone in Glyphward's adversarial industrial AI monitoring corpus.

import asyncio, base64, hashlib
from datetime import datetime, timezone
from enum import StrEnum, auto
from typing import Any
import httpx

GLYPHWARD_API = "https://api.glyphward.com/v1/scan"
GLYPHWARD_KEY = "gw_prod_***"

# Polycarbonate PC BPA interfacial phosgenation AI contexts: threshold 43
# OSHA PSM phosgene (COCl2) TQ 500 lbs (29 CFR 1910.119 App. A).
# EPA RMP phosgene TQ 500 lbs (40 CFR Part 68.130).
# Phosgene OSHA PEL 0.1 ppm ceiling; NIOSH IDLH 2 ppm; WWI chemical weapon.
# DCM OSHA 29 CFR 1910.1052 carcinogen; IARC Group 2A; CYP2E1 CO metabolism.
# Safety-critical PC applications: FAR 25.775 aircraft glazing; NIJ 0108.01 Level III bulletproof.
# 105th upward attack. FIRST PC production AI attack. FIRST BPA phosgenation AI attack.
PC_GLYPHWARD_THRESHOLD = 43

class PCPhosgenationContext(StrEnum):
    PHOSGENE_FEED_RATE           = auto()  # COCl2 Coriolis feed to BPA reactor (105th; FIRST PC; FIRST BPA phosgenation; FIRST Makrolon/Lexan)
    PTBP_CHAIN_TERMINATOR_FEED   = auto()  # p-TBP EM flow meter -> absent terminator -> Mw >150k -> extruder torque exceeded
    DCM_SCRUBBER_OUTLET_CONC     = auto()  # activated-carbon bed outlet DCM -> 318 ppm -> CYP2E1 CO -> COHb 20-25%

async def scan_pc_frame(
    frame_b64: str,
    context: PCPhosgenationContext,
    plant_id: str,
    instrument_tag: str,
) -> dict[str, Any]:
    payload = {
        "image_b64": frame_b64,
        "context": context,
        "plant_id": plant_id,
        "instrument_tag": instrument_tag,
        "scan_ts": datetime.now(timezone.utc).isoformat(),
        "image_hash": hashlib.sha256(base64.b64decode(frame_b64)).hexdigest(),
    }
    async with httpx.AsyncClient(timeout=4.0) as client:
        r = await client.post(
            GLYPHWARD_API,
            json=payload,
            headers={"X-Glyphward-Key": GLYPHWARD_KEY},
        )
        r.raise_for_status()
        return r.json()

async def pre_scan_gate_pc(
    frame_b64: str,
    context: PCPhosgenationContext,
    plant_id: str,
    instrument_tag: str,
) -> None:
    """Block adversarially manipulated PC BPA phosgenation display images before AI inference.

    Plants: COVESTRO_UERDINGEN | SABIC_MT_VERNON | TEIJIN_MATSUYAMA | LGCHEM_DAESAN
    Raises AdversarialPCImageError if adversarial_score >= PC_GLYPHWARD_THRESHOLD (43).
    """
    result = await scan_pc_frame(frame_b64, context, plant_id, instrument_tag)
    if result["adversarial_score"] >= PC_GLYPHWARD_THRESHOLD:
        raise AdversarialPCImageError(
            f"Adversarial injection detected in {context} (score {result['adversarial_score']}) "
            f"at plant {plant_id} instrument {instrument_tag}. "
            "Frame withheld from PC BPA phosgenation AI monitoring pipeline."
        )

class AdversarialPCImageError(RuntimeError):
    pass