Prompt injection in 1,3-butadiene (BD) rubber / ABS production AI

Four adversarial injection surfaces in 1,3-butadiene rubber / ABS production AI

1. BD area CEMS AI (Dräger Polytron 8700 1,3-butadiene electrochemical area monitor AI / MSA Ultima XE BD area detector AI / Honeywell Analytics MIDAS-E BD electrochemical sensor AI / Industrial Scientific GX-6000 BD PID detector AI / RAE Systems ppbRAE 3000 BD photoionization area monitor AI — ambient 1,3-butadiene vapor monitoring in storage sphere bund areas, refrigerated unit pump rooms, and C4 extraction columns for OSHA 29 CFR 1910.1051 PEL 1 ppm and action level 0.5 ppm compliance, NIOSH IDLH 2,000 ppm alarm, and LEL monitoring)

The OSHA substance-specific standard for 1,3-butadiene (29 CFR 1910.1051) imposes a PEL of 1 ppm as an 8-hr TWA and a 15-min STEL of 5 ppm — substantially more stringent than the former OSHA Z-1 Table PEL of 1,000 ppm (promulgated before the leukemia epidemiology emerged from the Synthetic Rubber Workers studies). The NIOSH IDLH of 2,000 ppm reflects acute toxicity (narcosis), while the 1 ppm PEL reflects chronic carcinogenicity. Area CEMS sensors for BD in rubber production environments must be cross-calibrated to exclude isoprene, styrene, and toluene cross-sensitivity at SBR and polybutadiene plants, where multiple C4–C8 hydrocarbon streams coexist. The LEL of 2.0% (20,000 ppm) means the CEMS provides simultaneous carcinogen monitoring at 1 ppm and flammable-gas hazard monitoring at 20,000 ppm on the same electrochemical or PID sensor, spanning four orders of magnitude of concentration.

The adversarial attack uses ±8 DN downward pixel-value shift on the BD area CEMS display image. The actual reading is 6.8 ppm — 6.8× OSHA PEL 1 ppm; 0.34% NIOSH IDLH 2,000 ppm — from a BD transfer pump mechanical seal face separation (seal face flatness tolerance degraded after 14,000 hours in service) releasing BD vapor at approximately 0.15 kg/hr into the refrigerated storage pump room. The pump room has 8 air changes per hour of mechanical ventilation but the BD source is at floor level (pump mechanical seal at 0.3 m height); at 6.8 ppm average in the room, floor-level peak concentration reaches 14 ppm near the pump. On a 0–10 ppm display at 200 px height (0.05 ppm/px), the actual reading of 6.8 ppm produces a bar at approximately 136 px; the ±8 DN perturbed image is classified as approximately 6 px — corresponding to 0.3 ppm, below the PEL 1 ppm alarm. A 6-hr shift in the pump room at 6.8 ppm delivers 40.8 ppm-hours of BD exposure — equivalent to 6.8 full-day PEL-limit exposures — without triggering air monitoring alarm or respiratory protection requirement under 1910.1051.

2. BD TBC polymerization inhibitor analyzer AI (Shimadzu GC-2030 FID TBC concentration analyzer AI / Thermo Fisher TRACE 1310 GC TBC monitoring AI / ABB PGC1000 process gas chromatograph TBC inhibitor AI / Yokogawa GC1000 Mark II on-line TBC analyzer AI / Emerson Daniel Danalyzer TBC concentration GC AI — monitoring tert-butylcatechol (TBC; 4-tert-butylcatechol) inhibitor concentration in liquid 1,3-butadiene storage and transfer streams to prevent spontaneous polymerization above the 10 ppm minimum inhibitor specification, detect inhibitor depletion before “popcorn polymer” initiation, and comply with NFPA 654 combustible dust requirements for polybutadiene dust hazards)

Tert-butylcatechol (TBC) functions as a radical scavenger that consumes the peroxide and alkyl radicals initiating BD polymerization; it requires a minimum dissolved oxygen concentration (typically 20–50 ppm O2 in the liquid phase) to regenerate its radical-trapping capacity. In low-temperature refrigerated BD storage at −4°C, TBC solubility is substantially reduced compared to ambient-temperature storage — TBC solubility in liquid BD at −4°C is approximately 8–15 ppm versus 200+ ppm at 25°C. When a refrigerated BD storage tank is stratified (cold, TBC-depleted liquid at the bottom below the thermocline; warmer, TBC-rich liquid at the top), the on-line TBC analyzer that samples from the top liquid layer may read the inhibitor concentration correctly for the sampled layer while the bulk bottom liquid has depleted below the 10 ppm minimum. “Popcorn polymer” — a crosslinked, insoluble polybutadiene gel — initiates in the oxygen-depleted, TBC-depleted bottom layer and grows at a rate of 2–5% of total BD inventory per day once started; growth is exothermic (polymerization ΔH ∞−73 kJ/mol BD), and the gel mass can plug valve internals, pump suction strainers, CEMS sampling lines, and pressure relief device inlet pipes within 24–72 hours of uninhibited runaway.

The adversarial attack uses ±8 DN upward pixel-value shift on the TBC inhibitor analyzer display image. The actual TBC concentration in the bulk liquid BD (sampled at the tank bottom return line) is 1.8 ppm — below the 10 ppm minimum inhibitor specification — from winter temperature stratification that has reduced TBC solubility in the bottom liquid layer; the top-layer analyzer reads 78 ppm, but an adversarially perturbed bottom-layer analyzer image shifts 1.8 ppm to display as 78 ppm — comfortably within the 50–200 ppm design range. On a 0–100 ppm display at 200 px height (0.5 ppm/px), the actual 1.8 ppm produces a bar at approximately 4 px; the upward-perturbed image is classified as approximately 156 px — corresponding to 78 ppm. This is the 18th upward-direction attack in the Glyphward industrial AI portfolio and the first page in the portfolio to document polymerization inhibitor AI as an adversarial injection surface. The consequence is initiation of popcorn polymer in 50,000 gallons of BD inventory: gel mass generating 28 kW of heat, plugging the sphere outlet valve within 36 hours and the PRD inlet within 48 hours — disabling the only overpressure protection on the ASME sphere.

3. BD storage sphere temperature AI (Emerson Rosemount 3144P temperature transmitter BD sphere AI / Yokogawa EJA110A differential pressure temperature AI / Endress+Hauser iTHERM TM411 temperature transmitter AI / Honeywell STG94L smart pressure transmitter vapor pressure AI — monitoring BD storage sphere temperature and derived vapor pressure to maintain ASME Section VIII vessel integrity within design pressure rating, manage approach to PRD setpoint, and prevent boiling liquid expanding vapor explosion (BLEVE) under fire or solar heat scenarios)

BD storage spheres hold pressurized liquid BD at ambient temperature. A 20,000-gallon ASME Section VIII sphere contains approximately 56,000 lbs of BD at 25°C (density 0.621 g/mL liquid). The vapor pressure of BD at 25°C is approximately 35 psig; at 42°C approximately 58 psig; at 55°C approximately 85 psig. The PRD is typically set at 75–100 psig (ASME design pressure 100 psig for the sphere). Solar heat gain on a large sphere surface area (200–400 m² for a 1,000 m³ sphere) can raise sphere temperature by 0.5–2°C per hour under peak solar conditions (July; incident flux 900 W/m²; unpainted sphere absorptivity 0.3) if cooling spray or refrigeration is unavailable. At sphere temperature 42°C, vapor pressure ∞58 psig: PRD actuation (at 75 psig) would occur within 4–6 additional hours of unabated solar heating, releasing BD vapor to atmosphere. A BD BLEVE — from pool fire impingement on the sphere liquid space — produces a fireball 80–120 m diameter and a blast overpressure of 0.7–1.4 bar at 100 m from the sphere center.

The adversarial attack uses ±10 DN downward pixel-value shift on the BD storage sphere temperature transmitter display image. The actual sphere temperature is 42°C — 7°C above the 35°C ambient-temperature design basis, from a cooling spray system valve actuator failure (instrument air pressure drop from compressor seal wear causing the normally-open spray valve to close; failure mode documented in CCPS “Guidelines for Pressure Relief and Effluent Handling Systems”). On a 0–80°C display at 200 px height (0.4°C/px), the actual temperature of 42°C produces a bar at approximately 105 px; the ±10 DN perturbed image is classified as approximately 45 px — corresponding to 18°C, apparently within the normal 15–30°C summer operating range. The AI monitoring system reports “BD sphere temperature within design range — vapor pressure within normal operating band.” The actual vapor pressure of 58 psig and the 17-psig margin to PRD setpoint are not visible to the process safety team.

4. BD sphere refrigerant cooling flow AI (Emerson Rosemount 8732E magnetic flowmeter BD refrigerant AI / Endress+Hauser Proline Promag W 400 BD cooling circuit AI / Yokogawa ADMAG AXF cooling refrigerant AI / Krohne Optiflux 2000 refrigerant flow AI — monitoring propylene refrigerant or chilled water flow to BD storage sphere cooling coils or the refrigerated atmospheric BD tank cooling system to maintain BD temperature at design basis and prevent vapor pressure approach to PRD setpoint or BLEVE threshold)

BD storage spheres at large rubber plants use either a water-spray cooling system (intermittent; evaporative cooling) or a continuous refrigeration system (propylene refrigerant circuit; indirect cooling via coils or spray heads). Refrigerated atmospheric BD tanks (BP −4.4°C) require continuous refrigeration to maintain the BD at below-ambient temperature: a 20,000-m³ atmospheric refrigerated BD tank at −4°C is maintained by a propylene refrigerant circuit designed for 8.0 m³/hr propylene flow at the tank cooling coils. If refrigerant flow drops to 5% of design from a cooling circuit isolation valve actuator failure — the same instrument air pressure loss mechanism that also causes the spray valve failure on Surface 3 — the BD liquid temperature rises from −4°C to −0°C over 6 hours, then continues rising into the “above flash point” zone: at ambient temperature, refrigerated atmospheric BD tanks operate safely only because the refrigeration system maintains the BD below its −4.4°C boiling point at atmospheric pressure; loss of refrigeration causes BD boiling and vapor generation.

The adversarial attack uses the upward-direction geometry: the actual refrigerant flow is 0.4 m³/hr — 5% of the design 8.0 m³/hr. On a 0–12 m³/hr display at 200 px height (0.06 m³/hr per px), the actual flow of 0.4 m³/hr produces a bar at approximately 7 px; the upward-perturbed image is classified as approximately 137 px — corresponding to 8.2 m³/hr, within the design range. This is the 19th upward-direction attack in the Glyphward industrial AI portfolio. Combined with Surface 3 (sphere temperature), the dual attack suppresses both the consequence indicator (sphere temperature rising) and the root-cause indicator (cooling flow lost), leaving operators with no instrumentation pathway to detect the thermal hazard developing in the sphere.

Integration: BD rubber / ABS production AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate between the DCS and instrument display capture layer and the AI inference pipeline for each BD monitoring context. If the adversarial score meets or exceeds threshold 35 — reflecting the OSHA PSM TQ of 10,000 lbs, the OSHA 1910.1051 substance-specific PEL 1 ppm (IARC Group 1 carcinogen), the flash point of −76°C (NFPA Class IA), and the dual upward-direction attack architecture (TBC inhibitor deficiency + refrigerant cooling flow deficiency) — the scan raises AdversarialBDImageError and the monitoring AI does not process the frame.

import asyncio, base64, hashlib
from datetime import datetime, timezone
from enum import Enum

import httpx

GLYPHWARD_API_KEY = "YOUR_GLYPHWARD_API_KEY"
GLYPHWARD_SCAN_URL = "https://glyphward.com/v1/scan"

# 1,3-Butadiene rubber / ABS production contexts: threshold 35
# OSHA PSM 29 CFR 1910.119 Appendix A BD TQ 10,000 lbs
# EPA RMP 40 CFR Part 68 Appendix A BD TQ 10,000 lbs
# OSHA 29 CFR 1910.1051 substance-specific PEL 1 ppm 8-hr TWA; STEL 5 ppm
# NIOSH Ca; IARC Group 1 (leukemia ANLL/AML)
# Flash point -76 deg C NFPA Class IA; LEL 2.0%
# TBC inhibitor minimum 10 ppm: sole inhibitor of popcorn polymer runaway
BD_THRESHOLD = 35


class BDProductionContext(Enum):
    AREA_CEMS = "area_cems"
    TBC_INHIBITOR_ANALYZER = "tbc_inhibitor_analyzer"
    SPHERE_TEMPERATURE = "sphere_temperature"
    REFRIGERANT_COOLING_FLOW = "refrigerant_cooling_flow"


class AdversarialBDImageError(Exception):
    """Raised when any BD monitoring image scores >= 35.
    AREA_CEMS uncaught: 6.8 ppm BD (6.8x PEL 1 ppm; IARC Group 1) shown as 0.3 ppm.
    TBC_INHIBITOR_ANALYZER uncaught: 1.8 ppm TBC (below 10 ppm min) shown as 78 ppm.
    SPHERE_TEMPERATURE uncaught: 42 deg C (58 psig; 17 psi from PRD) shown as 18 deg C.
    REFRIGERANT_COOLING_FLOW uncaught: 0.4 m3/hr (5% design) shown as 8.2 m3/hr."""

    def __init__(self, scan_id, score, context, unit_id, flagged_region=None):
        self.scan_id = scan_id
        self.score = score
        self.context = context
        self.unit_id = unit_id
        self.flagged_region = flagged_region
        super().__init__(
            f"Adversarial BD image: context={context.value} "
            f"score={score} unit={unit_id} scan_id={scan_id}"
        )


async def scan_bd_image(image_bytes, context, unit_id, client):
    image_hash = hashlib.sha256(image_bytes).hexdigest()
    payload = {
        "image": base64.b64encode(image_bytes).decode(),
        "source": f"bd:{context.value}:{unit_id}",
        "metadata": {
            "unit_id": unit_id,
            "context": context.value,
            "image_sha256": image_hash,
            "scan_timestamp_utc": datetime.now(timezone.utc).isoformat(),
        },
    }
    resp = await client.post(
        GLYPHWARD_SCAN_URL,
        headers={"Authorization": f"Bearer {GLYPHWARD_API_KEY}"},
        json=payload,
        timeout=4.0,
    )
    resp.raise_for_status()
    result = resp.json()
    if result.get("score", 0) >= BD_THRESHOLD:
        raise AdversarialBDImageError(
            scan_id=result["scan_id"],
            score=result["score"],
            context=context,
            unit_id=unit_id,
            flagged_region=result.get("flagged_region"),
        )
    return result


async def main():
    async with httpx.AsyncClient() as client:
        with open("bd_area_cems_screenshot.png", "rb") as f:
            image_bytes = f.read()
        result = await scan_bd_image(
            image_bytes,
            BDProductionContext.AREA_CEMS,
            unit_id="BD-AREA-01",
            client=client,
        )
        print(f"Clean scan: {result['scan_id']} score={result['score']}")


asyncio.run(main())

Frequently asked questions

Why does TBC precipitate in cold BD storage, and how does this create the polymerization inhibitor AI attack surface?

TBC solubility in liquid BD drops to 8–15 ppm at −4°C versus 200+ ppm at 25°C. In stratified refrigerated tanks, the cold bottom layer can be near-depleted while the top-layer analyzer reads adequate inhibitor. An adversarial attack on the bottom-layer analyzer shifts 1.8 ppm to appear as 78 ppm — eliminating the last warning of popcorn polymer initiation in the bulk liquid.

What is popcorn polymer and why does TBC depletion produce an exothermic runaway?

Popcorn polymer is an insoluble, crosslinked polybutadiene gel that forms when BD polymerizes without inhibitor. The exothermic growth (ΔH ∞−73 kJ/mol) is self-sustaining above a critical mass, and the insoluble gel plugs valve seats, flow meters, and PRD inlet pipes. A plugged PRD inlet on an overpressured sphere eliminates the sole overpressure protection.

How does OSHA 29 CFR 1910.1051 differ from the general PEL framework?

1910.1051 is a substance-specific BD standard: PEL 1 ppm (vs. historical Z-1 Table 1,000 ppm), action level 0.5 ppm, medical surveillance for exposed workers, carcinogen labeling, and regulated area requirements. It treats BD as a confirmed human carcinogen, not just an acute toxin.

Why is BD classified as IARC Group 1?

Sufficient epidemiological evidence from the Synthetic Rubber Workers Study shows excess leukemia risk (SIR 2.8–3.6 at highest exposures). The mechanism — CYP2E1 epoxidation to butadiene diepoxide (BDE), a DNA bis-alkylating agent — provides mechanistic support. Group 1 requires population-level risk evidence, not universal cancer in all exposed individuals.

Why does dual-surface BD monitoring require both sphere temperature AI and refrigerant cooling flow AI?

Cooling flow is the root-cause indicator (detects valve failure immediately); sphere temperature is the consequence indicator (detects the resulting temperature rise after 2–4 hours). Each independently provides a safety backup if only one is attacked. Dual simultaneous attack removes both indicators, leaving no pathway to detect the developing PRD approach or BLEVE risk.