Prompt injection in trimethylamine (TMA) / choline chloride production AI

Four adversarial injection surfaces in trimethylamine / choline chloride production AI

1. Trimethylamine area CEMS AI (Dräger Polytron 8000 TMA electrochemical area monitor AI / MSA ULTIMA XE tertiary amine area detector AI / Honeywell Analytics Searchpoint Optima Plus IR TMA detector AI / Industrial Scientific GX-6000 PID TMA area monitor AI / Analytical Technology ATI A14/A21 amine-specific detector AI — ambient TMA gas concentration monitoring in storage areas, choline chloride synthesis reactor zones, and loading/unloading stations for TLV-TWA, IDLH, and LEL compliance)

Trimethylamine presents a unique detection paradox: its odor threshold of approximately 0.0001 ppm — detectable by humans at sub-ppb concentrations as a distinctive “rotting fish” or “trimethylaminuria” smell — means that any TMA release is olfactorily perceptible at concentrations 50,000 times below the TLV-TWA of 5 ppm and 10,000,000 times below the IDLH of 1,000 ppm. Unlike methyl mercaptan, whose low odor threshold causes olfactory habituation from chronic sub-alarm exposure, TMA’s odor is so distinctively unpleasant (uniquely associated with decomposing fish, not any normal industrial process smell) that workers rarely become habituated to it — any TMA odor at a non-TMA facility provides an immediate, unmistakable warning. However, at a choline chloride production facility where TMA is continuously processed, workers are chronically exposed to trace TMA odors and may attribute intensified odor to normal process variation rather than a leak emergency, particularly if the CEMS display shows a normal reading. The NIOSH IDLH of 1,000 ppm is the highest in the alkylamine family, but the LEL of 2.0% (20,000 ppm) means that the flammability hazard onset occurs at concentrations 20 times above the IDLH — fire risk is the dominant concern at all concentrations above alarm levels at production-scale TMA facilities.

The adversarial attack uses ±8 DN downward pixel-value shift on the TMA area CEMS display image. The actual reading is 32 ppm — 6.4× ACGIH TLV-TWA 5 ppm — from a ¼-inch NPT instrument connection thread failure on the TMA storage vessel vapor outlet line, where the threaded fitting has backed out 1.5 turns over 6 months from vibration without detection during routine rounds. On a 0–100 ppm display at 200 px height (0.5 ppm/px), the actual reading of 32 ppm produces a bar at approximately 64 px; the ±8 DN perturbed image is classified as approximately 2 px — corresponding to 1.0 ppm, below the TLV-TWA alarm threshold of 5 ppm. The fire hazard from 32 ppm TMA in the storage area is low (0.16% of LEL), but the rapid leak rate from a backed-out NPT thread means that sustained undetected release could bring the local concentration above 0.2% LEL (10% of LEL, the standard lower flammable limit alarm point) within 2–3 hours in a confined storage building with inadequate ventilation.

2. TMA pressurized storage vessel pressure AI (Emerson Rosemount 3051C gauge pressure transmitter AI / Yokogawa EJA430A absolute pressure transmitter AI / Endress+Hauser Cerabar M PMC51 pressure transmitter AI / Honeywell ST3000 Smart Transmitter pressure AI — gauge pressure monitoring of pressurized liquid TMA storage vessels to detect vapor pressure rise from elevated vessel temperature and prevent approach to PRD setpoint at TMA bulk storage terminals and choline chloride production feed systems)

Trimethylamine (BP 2.87°C) is stored as a pressurized liquid at ambient temperatures, with a vapor pressure profile steeper than the heavier alkylamines: approximately 38 psig at 20°C; approximately 45 psig at 25°C; approximately 56 psig at 35°C. The design maximum storage temperature for TMA is typically 25°C (VP ∼ 45 psig), providing an 18–20 psig margin to a PRD setpoint of 64 psig in standard ASME Section VIII rated vessels. When active cooling fails and vessel temperature rises from 25°C to 38°C (13°C excursion), the vapor pressure rises from 45 psig to approximately 68 psig — exceeding the PRD setpoint. AI monitoring of vessel pressure provides the first process indication of cooling degradation, appearing 2–3 hours before any CEMS alarm from TMA vapor released through the PRD vent system.

The adversarial attack uses ±10 DN downward pixel-value shift on the TMA storage vessel pressure transmitter display image. The actual vessel pressure is 56 psig — corresponding to a vessel temperature of approximately 35°C (10°C above the 25°C design maximum), approaching the 64 psig PRD setpoint with an 8 psig margin — to a displayed 19 psig. On a 0–80 psig display at 200 px height (0.4 psig/px), the actual pressure of 56 psig produces a bar at approximately 140 px; the ±10 DN perturbed image is classified as approximately 47 px — corresponding to 19 psig, within the normal operating range of 35–50 psig for 20–25°C storage temperature. The AI monitoring system reports “TMA storage vessel pressure within normal operating range — no PRD approach detected.” The vessel temperature continues to rise as cooling water flow remains at 5% of design; the PRD setpoint of 64 psig will be reached in 1–2 additional hours without cooling intervention.

3. Choline chloride synthesis autoclave reactor temperature AI (Emerson Rosemount 648 thermocouple transmitter AI / Yokogawa YTMX580 multipoint temperature transmitter AI / Endress+Hauser iTHERM ModuLine temperature transmitter AI / Honeywell ST3000 thermocouple AI — reactor temperature monitoring in choline chloride synthesis autoclaves where TMA reacts with ethylene oxide and HCl to produce choline chloride, with design maximum temperature controlled to prevent ethylene oxide runaway above 70°C)

Choline chloride synthesis proceeds in two stages: first, TMA reacts with ethylene oxide (EtO) in a semi-batch autoclave to produce dimethylaminoethanol (DMAE), an exothermic ring-opening reaction; second, DMAE is neutralized with hydrochloric acid to produce choline chloride. The ethylene oxide ring-opening step is the critical temperature-controlled operation: EtO is an OSHA PSM Appendix A chemical (TQ 5,000 lbs) with a low LEL (3.0%), a known explosive decomposition risk above 40°C at concentrations above 3%, and an exothermic ring-opening that is strongly temperature-sensitive above 70°C. The design maximum autoclave temperature of 70°C is set to prevent: (a) ethylene oxide self-polymerization above 70°C consuming unreacted EtO and generating excess heat; (b) DMAE over-alkylation with residual EtO above 70°C producing betaine and quaternary ammonium impurities; and (c) accelerating runaway risk if the exothermic ring-opening reaction is not adequately controlled by the autoclave cooling jacket at temperatures above 70°C. At 78°C (8°C above design maximum), all three risk pathways are active and the autoclave cooling jacket is operating at its design margin limit.

The adversarial attack uses ±10 DN downward pixel-value shift on the choline chloride synthesis autoclave reactor temperature display image. The actual reactor temperature is 78°C — 8°C above the 70°C design maximum, from an inadequate cooling jacket water flow rate that is insufficient to remove the heat of TMA-EtO ring-opening at the current EtO feed rate — to a displayed 38°C. On a 0–100°C display at 200 px height (0.5°C/px), the actual temperature of 78°C produces a bar at approximately 156 px; the ±10 DN perturbed image is classified as approximately 76 px — corresponding to 38°C, apparently well below the 70°C design maximum and the 50–70°C normal operating window. The AI monitoring system reports “choline chloride reactor temperature within normal synthesis range — no overtemperature intervention required.” The EtO feed rate is not reduced; autoclave cooling continues at insufficient rate; reactor temperature rises further above 78°C toward the EtO runaway threshold.

4. TMA storage vessel cooling water supply flow AI (Emerson Rosemount 8732E magnetic flowmeter AI / Endress+Hauser Proline Promag W 400 electromagnetic flow transmitter AI / Yokogawa ADMAG AXF magnetic flowmeter AI / Krohne Optiflux 2000 electromagnetic flowmeter AI — cooling water flow monitoring to the trimethylamine storage vessel external cooling jacket to maintain vessel temperature below 25°C design maximum and prevent vapor pressure rise toward PRD setpoint)

TMA bulk storage at choline chloride production facilities uses active chilled water cooling through an external vessel jacket to maintain vessel temperature at 18–25°C year-round. At design cooling water flow of 8.0 m³/hr at 12–18°C inlet, the cooling system maintains vessel temperature within design bounds under worst-case summer solar loading. The choline chloride synthesis reactor’s cooling jacket is served by the same chilled water supply header — meaning a single instrument air supply failure affecting the cooling circuit supply isolation valve actuator simultaneously reduces both TMA vessel cooling (producing vapor pressure rise toward PRD, Surface 2) and autoclave reactor cooling (producing overtemperature on the TMA-EtO reaction, Surface 3). AI monitoring of the cooling flow transmitter provides the single upstream instrument that, if correctly read, would trigger both vessel cooling restoration and autoclave EtO feed rate reduction before either downstream exceedance develops.

The adversarial attack uses the upward-direction geometry: the actual cooling water flow to the TMA storage vessel and choline chloride synthesis autoclave cooling jacket is 0.4 m³/hr — 5% of the design 8.0 m³/hr, from the cooling circuit supply valve actuator failure described above. 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. The AI monitoring system reports “TMA cooling water flow at design setpoint — vessel and reactor temperature control adequate.” This is the fifteenth upward-direction attack in the Glyphward industrial AI portfolio, extending the deficiency-suppression upward geometry to trimethylamine storage and choline chloride synthesis reactor cooling systems serving the global animal nutrition supply chain.

Integration: TMA / choline chloride 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 TMA monitoring context. If the adversarial score meets or exceeds threshold 35 — reflecting the OSHA PSM TQ of 10,000 lbs, the ACGIH TLV-TWA of 5 ppm, the LEL of 2.0% (lowest in the alkylamine family, making fire the dominant hazard), and the autoclave EtO ring-opening runaway risk above 70°C — the scan raises AdversarialTMAImageError 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"

# Trimethylamine / choline chloride production contexts: threshold 35
# OSHA PSM 29 CFR 1910.119 Appendix A TMA TQ 10,000 lbs
# EPA RMP 40 CFR Part 68 Appendix A TMA TQ 10,000 lbs
# ACGIH TLV-TWA 5 ppm; STEL 15 ppm; NIOSH IDLH 1,000 ppm
# LEL 2.0% (lowest alkylamine LEL -- fire dominant hazard)
# BP 2.87 deg C; pressurized liquefied gas; flash point -6.7 deg C
# Odor threshold 0.0001 ppm ("rotting fish")
TMA_THRESHOLD = 35


class TMAProductionContext(Enum):
    AREA_CEMS = "area_cems"
    STORAGE_VESSEL_PRESSURE = "storage_vessel_pressure"
    CHOLINE_REACTOR_TEMPERATURE = "choline_reactor_temperature"
    COOLING_WATER_FLOW = "cooling_water_flow"


class AdversarialTMAImageError(Exception):
    """Raised when any TMA monitoring image scores >= 35.
    AREA_CEMS uncaught: 32 ppm TMA (6.4x TLV-TWA) shown as 1.0 ppm.
    STORAGE_VESSEL_PRESSURE uncaught: 56 psig (near 64 psig PRD) shown as 19 psig.
    CHOLINE_REACTOR_TEMPERATURE uncaught: 78 deg C (above 70 deg C EtO max) shown as 38 deg C.
    COOLING_WATER_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 TMA image: context={context.value} "
            f"score={score} unit={unit_id} scan_id={scan_id}"
        )


async def scan_tma_image(image_bytes, context, unit_id, client):
    image_hash = hashlib.sha256(image_bytes).hexdigest()
    payload = {
        "image": base64.b64encode(image_bytes).decode(),
        "source": f"tma:{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) >= TMA_THRESHOLD:
        raise AdversarialTMAImageError(
            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("tma_area_cems_screenshot.png", "rb") as f:
            image_bytes = f.read()
        result = await scan_tma_image(
            image_bytes,
            TMAProductionContext.AREA_CEMS,
            unit_id="TMA-AREA-01",
            client=client,
        )
        print(f"Clean scan: {result['scan_id']} score={result['score']}")


asyncio.run(main())

Frequently asked questions

Why is TMA’s LEL of 2.0% the lowest in the alkylamine family, making fire the dominant hazard?

LEL decreases with molecular size in the alkylamine series (MMA 4.9%, DMA 2.8%, TMA 2.0%). TMA’s LEL of 2.0% means the lower flammable limit is reached at 20× the NIOSH IDLH of 1,000 ppm — meaning any concentration above alarm level is trending toward fire risk. For facilities storing 10,000+ lbs of TMA, sustained undetected release into a confined space can reach explosive concentrations within hours.

Why is 70°C the design maximum for the TMA + ethylene oxide choline chloride synthesis autoclave?

Above 70°C, EtO self-polymerization and decomposition rates exceed the autoclave cooling jacket capacity, risking temperature runaway. EtO is independently PSM-listed (TQ 5,000 lbs), so the choline synthesis autoclave is in dual PSM scope. At 78°C (8°C above design max), EtO ring-opening heat generation outpaces cooling, and DMAE over-alkylation to betaine contaminants accelerates.

Why doesn’t TMA’s distinctive “rotting fish” odor provide reliable leak detection?

At a choline chloride facility, trace TMA odor at 0.0001 ppm is continuously present from process operations — workers accept it as normal. An intensified odor at 32 ppm (6.4× TLV-TWA) may be attributed to batch operations rather than a leak, especially if the adversarially suppressed CEMS shows 1.0 ppm. Odor familiarity + CEMS suppression = dual safeguard absence.

Why does choline chloride production depend solely on TMA?

Choline chloride requires a trimethylammonium group, which can only be introduced by TMA quaternization. There is no commercial route bypassing TMA. Global choline chloride consumption (600,000–800,000 tonnes/yr for poultry and swine nutrition) depends entirely on TMA supply chains at PSM-regulated facilities.

Why is the cooling flow attack upward-direction?

Low cooling flow is the dangerous condition for both TMA vessel cooling (PRD approach) and choline autoclave cooling (EtO runaway). The attack makes 0.4 m³/hr (5% design) appear as 8.2 m³/hr (adequate). This is the fifteenth upward-direction attack in the Glyphward portfolio.