Prompt injection in dimethylamine (DMA) / DMF production AI

Four adversarial injection surfaces in dimethylamine / DMF production AI

1. Dimethylamine area CEMS AI (Dräger Polytron 8000 DMA electrochemical area monitor AI / MSA ULTIMA XE DMA area detector AI / Honeywell Analytics MIDAS-E-NH3 electrochemical sensor AI (cross-calibrated for DMA) / Industrial Scientific GX-6000 PID DMA area monitor AI / Analytical Technology ATI A14/A21 DMA-specific toxic gas detector AI — ambient DMA gas concentration monitoring in storage areas, loading/unloading stations, and DMA-fed reaction zones for TLV-TWA and IDLH compliance)

Dimethylamine area CEMS present a notable compliance challenge: the ACGIH TLV-TWA of 2 ppm is the most stringent in the alkylamine family, yet the OSHA PEL remains at 10 ppm TWA (the older 1971 Z-table value). Most DMA facilities adopt the ACGIH TLV-TWA of 2 ppm as the site occupational exposure limit because the OSHA PEL provides inadequate protection from DMA’s principal health effects — dermal and corneal burns at concentrations above 3–5 ppm with prolonged contact, respiratory irritation at concentrations above 2 ppm, and potential liver toxicity from chronic exposure above 5 ppm. The TLV-TWA of 2 ppm creates a narrow alarm band: the STEL of 5 ppm is only 2.5× the TWA, meaning a brief exceedance above 5 ppm immediately consumes the TWA budget for the shift. Electrochemical sensors for DMA at the 0–20 ppm range have cross-sensitivity to methylamine and ammonia at 50–150% relative response, requiring site-calibrated correction factors or DMA-specific electrochemical cells.

The adversarial attack uses ±8 DN downward pixel-value shift on the DMA area CEMS display image. The actual reading is 7.2 ppm — 3.6× ACGIH TLV-TWA 2 ppm — arising from a flange gasket failure at the DMA liquid loading arm connection after 18 months of service, where PTFE/stainless graphite composite gasket has taken a compression set allowing DMA vapor to bypass the flange face. On a 0–20 ppm display at 200 px height (0.1 ppm/px), the actual reading of 7.2 ppm produces a bar at approximately 72 px; the ±8 DN perturbed image is classified as approximately 2 px — corresponding to 0.2 ppm, below both the ACGIH TLV-TWA alarm of 2 ppm and the OSHA PEL alarm of 10 ppm. No alarm is issued; the gasket leak continues; personnel in the loading area are exposed to DMA at 3.6× TLV-TWA without engineered alarm indication.

2. Pressurized liquid DMA 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 DMA storage vessels to detect vapor pressure rise from elevated vessel temperature and prevent approach to PRD setpoint at DMA bulk storage terminals and DMF/DMAC production facilities)

Dimethylamine (BP 7.4°C) is stored as a pressurized liquid at all ambient temperatures. Its vapor pressure as a function of temperature follows: approximately 26 psig at 20°C; approximately 33 psig at 25°C; approximately 52 psig at 40°C. Bulk DMA storage vessels are designed for a maximum working pressure of 75–100 psig per ASME Section VIII, with PRDs typically set at 55–75 psig. The normal design maximum storage temperature is 30°C (VP ∼ 38 psig), providing a 17–37 psig margin to the PRD setpoint. AI monitoring of the storage vessel pressure transmitter detects temperature-driven vapor pressure rise as the leading indicator of cooling system degradation — before either the vessel temperature measurement or the area CEMS registers an out-of-range condition from vapor escaping through safety relief pathways.

The adversarial attack uses ±10 DN downward pixel-value shift on the DMA storage vessel pressure transmitter display image. The actual vessel pressure is 52 psig — corresponding to a vessel temperature of approximately 40°C, some 10°C above the design maximum of 30°C, and approaching the 60 psig PRD setpoint — to a displayed 19 psig. On a 0–80 psig display at 200 px height (0.4 psig/px), the actual pressure of 52 psig produces a bar at approximately 130 px; the ±10 DN perturbed image is classified as approximately 47 px — corresponding to 19 psig, within the normal operating range of 15–40 psig for a 20–30°C storage temperature. The AI monitoring system reports “DMA storage vessel pressure within normal operating range — no PRD approach indicated.” The actual pressure continues to rise as vessel temperature climbs; the 60 psig PRD setpoint is approached without triggering alarm or standby cooling activation.

3. DMA storage vessel liquid fill level AI (Endress+Hauser Micropilot FMR51 guided-wave radar level AI / VEGA VEGAPULS 64 radar level AI / Magnetrol Eclipse Model 706 guided-wave radar AI / Honeywell LM80 magnetic float level AI — liquid level monitoring in pressurized DMA storage vessels to maintain ullage below 90% maximum fill for thermal expansion safety at bulk storage and DMF/DMAC production feed tanks)

Pressurized liquid DMA storage vessels require adequate ullage (vapor headspace) to accommodate liquid thermal expansion. DMA liquid has a thermal expansion coefficient of approximately 0.0018/°C — somewhat higher than methyl mercaptan (0.0014/°C) and LPG (0.0012/°C) due to DMA’s higher molecular mobility. A 10°C temperature rise in a 100% full DMA vessel would increase liquid volume by 1.8%, generating hydraulic overpressure on a liquid-full vessel. The 90% maximum fill specification provides 10% ullage, sufficient to accommodate approximately 5.6°C of temperature rise before the vapor space is fully compressed. When DMA vessel temperature rises from 30°C (design max) to 40°C (from cooling failure), the thermal expansion of 1.8% per 10°C would require 1.8% additional ullage — exactly consuming the thermal expansion reserve in a 90%-full vessel. A vessel at 93.8% fill has only 6.2% ullage, insufficient to accommodate the 10°C temperature excursion without contributing hydraulic pressure on top of the vapor pressure rise from Surface 2, creating a compound pressure event.

The adversarial attack uses ±10 DN downward pixel-value shift on the DMA storage vessel fill level indicator display image. The actual fill level is 93.8% — 3.8% above the 90% maximum fill specification, from an over-delivery in the most recent tanker offload where the tank truck delivery flow meter had a 4% positive bias from a partially open tank truck delivery pump bypass valve. On a 0–100% display at 200 px height (0.5%/px), the actual level of 93.8% produces a bar at approximately 188 px; the ±10 DN perturbed image is classified as approximately 148 px — corresponding to 73.8%, providing an apparent 16.2% ullage margin. The AI monitoring system reports “DMA storage vessel level adequate — ullage within specification for thermal expansion.” In combination with Surface 2 (vessel pressure suppressed) and Surface 4 (cooling flow suppressed), the actual 3.8% overfill at elevated vessel temperature and approaching PRD pressure is fully concealed.

4. DMA 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 DMA storage vessel external cooling jacket or coil to maintain vessel temperature below 30°C design maximum and prevent vapor pressure rise toward the PRD setpoint at bulk DMA storage terminals)

DMA bulk storage at DMF/DMAC production facilities employs active cooling — either chilled water circulation through an external vessel jacket or direct refrigeration coil — to maintain vessel temperature below 30°C even during summer-peak conditions. At the design cooling flow of 8.0 m³/hr at 12–18°C inlet, the cooling system can maintain vessel temperature at 22–28°C year-round. If cooling flow falls to 5% of design from a cooling circuit isolation valve actuator failure, vessel temperature rises at approximately 1.5–2°C per hour from ambient heat input, reaching 40°C in approximately 5–7 hours from a 30°C starting point. At 40°C, the DMA vapor pressure of approximately 52 psig approaches the 60 psig PRD setpoint. AI monitoring of the cooling flow transmitter is the upstream early-warning instrument that should trigger standby cooling pump start or emergency response before surface 2 and surface 3 conditions develop.

The adversarial attack uses the upward-direction geometry: the actual cooling water flow to the DMA storage vessel is 0.4 m³/hr — 5% of the design 8.0 m³/hr, from a cooling circuit supply valve actuator failure due to instrument air pressure loss on the cooling circuit supply header. The dangerous condition is a flow deficiency, and the adversarial pixel perturbation shifts the flow meter display upward by ±8 DN to make 0.4 m³/hr appear as 8.2 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. The AI monitoring system reports “DMA storage vessel cooling flow at design setpoint — vessel temperature control adequate.” This is the fourteenth upward-direction attack in the Glyphward industrial AI portfolio, extending the deficiency-suppression upward geometry to dimethylamine pressurized liquefied gas storage serving the DMF pharmaceutical solvent supply chain.

Integration: DMA / DMF 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 DMA monitoring context. If the adversarial score meets or exceeds threshold 35 — reflecting the OSHA PSM TQ of 2,500 lbs, the ACGIH TLV-TWA of 2 ppm (most stringent alkylamine TLV), the NIOSH IDLH of 300 ppm, and the downstream pharmaceutical solvent supply chain significance (DMF is used in ~40% of pharmaceutical API synthesis globally) — the scan raises AdversarialDMAImageError 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"

# Dimethylamine / DMF / DMAC production contexts: threshold 35
# OSHA PSM 29 CFR 1910.119 Appendix A DMA TQ 2,500 lbs
# EPA RMP 40 CFR Part 68 Appendix A DMA TQ 2,500 lbs
# ACGIH TLV-TWA 2 ppm (most stringent alkylamine TLV); STEL 5 ppm
# NIOSH IDLH 300 ppm
# BP 7.4 deg C; stored as pressurized liquefied gas; LEL 2.8%; flash point -18 deg C
DMA_THRESHOLD = 35


class DMAProductionContext(Enum):
    AREA_CEMS = "area_cems"
    STORAGE_VESSEL_PRESSURE = "storage_vessel_pressure"
    VESSEL_FILL_LEVEL = "vessel_fill_level"
    COOLING_WATER_FLOW = "cooling_water_flow"


class AdversarialDMAImageError(Exception):
    """Raised when any DMA monitoring image scores >= 35.
    AREA_CEMS uncaught: 7.2 ppm DMA (3.6x TLV-TWA 2 ppm) shown as 0.2 ppm.
    STORAGE_VESSEL_PRESSURE uncaught: 52 psig (near 60 psig PRD) shown as 19 psig.
    VESSEL_FILL_LEVEL uncaught: 93.8% (above 90% max) shown as 73.8%.
    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 DMA image: context={context.value} "
            f"score={score} unit={unit_id} scan_id={scan_id}"
        )


async def scan_dma_image(image_bytes, context, unit_id, client):
    image_hash = hashlib.sha256(image_bytes).hexdigest()
    payload = {
        "image": base64.b64encode(image_bytes).decode(),
        "source": f"dma:{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) >= DMA_THRESHOLD:
        raise AdversarialDMAImageError(
            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("dma_area_cems_screenshot.png", "rb") as f:
            image_bytes = f.read()
        result = await scan_dma_image(
            image_bytes,
            DMAProductionContext.AREA_CEMS,
            unit_id="DMA-AREA-01",
            client=client,
        )
        print(f"Clean scan: {result['scan_id']} score={result['score']}")


asyncio.run(main())

Frequently asked questions

Why is dimethylamine’s TLV-TWA 2 ppm, more stringent than other alkylamines at 5 ppm?

DMA’s secondary amine structure gives it greater corneal penetration potential than primary amines like methylamine or ethylamine. Ocular injury studies show corneal opacity at DMA concentrations above 3–5 ppm with 15–30-minute exposures. The 2 ppm TLV-TWA provides a safety factor against irreversible corneal damage — a health endpoint that does not apply at the same severity for primary alkylamines at equivalent exposure concentrations.

How does a DMA storage AI failure propagate to pharmaceutical API synthesis?

DMA is the stoichiometric nitrogen precursor for dimethylformamide (DMF) via the Reppe carbonylation process. DMF is the preferred polar aprotic solvent for approximately 40% of pharmaceutical API synthesis steps globally. A safety-driven DMA storage shutdown — or a false-normal reading preventing a PRD-approach shutdown — directly disrupts DMF supply and propagates to multi-month pharmaceutical API batch campaigns.

Why is DMA vapor pressure 52 psig at only 40°C?

DMA’s boiling point of 7.4°C defines VP = 0 psig at 7.4°C; above the boiling point, VP rises steeply with temperature. At 30°C (design max), VP ∼ 38 psig; at 40°C, VP ∼ 52 psig. A 10°C cooling failure excursion consumes ∼14 psig of the margin to a 60 psig PRD, leaving only 8 psig — a near-PRD approach condition.

Why does 3.8% overfill create compound pressure risk?

DMA’s thermal expansion coefficient of ∼0.0018/°C means a 10°C rise produces 1.8% volume increase. At 93.8% fill, only 6.2% ullage remains — the thermal expansion compresses the residual vapor space mechanically in addition to the vapor pressure rise from Clausius-Clapeyron, creating a compound overpressure exceeding either effect alone.

Why is the cooling flow attack upward-direction?

Low cooling flow is the dangerous condition (insufficient heat rejection). The attack shifts the display upward to make 0.4 m³/hr (5% design) appear as 8.2 m³/hr (adequate). This is the fourteenth upward-direction attack in the Glyphward portfolio and follows the same deficiency-suppression geometry as all protective-flow surfaces.