← Risk register SOC 51-9012 · reviewed 2026-08-11

Separating, Filtering, Clarifying, Precipitating, and Still Machine Setters, Operators, and Tenders

60,100 US workers · median $51,610/yr · Production

EXPOSED

The screen half of this job — reading gauges, logging batch data, adjusting setpoints toward a spec, flagging drift — is exactly what distributed control systems and now predictive process software absorb, and headcount per unit has been falling for two decades. What holds is the physical half: swapping filter media, cleaning fouled plates and centrifuge bowls, pulling samples, chasing leaks and blockages, and hand-cranking a still or separator back through an upset when the automation loses the plot. Modal worker is a plant-floor operator on rotating shifts, not a control-room engineer, and that grounding in dirty confined equipment is the main reason the role isn't gone.

10-year outlook: Expect continued slow headcount decline as control systems get smarter and plants run leaner shifts, with surviving jobs skewing toward operator-mechanics who can fix, clean, and restart the equipment they run.

US employment, 2019–2025+17.5%
51,16060,100 workers

Dipped in 2020, then grew past where it started.

Median pay $41,330 → $51,610 -0.1% in real terms (nominal +24.9%, less ~25% US inflation over the period)

The job count is not the verdict

This line is counted by the Bureau of Labor Statistics — the one figure on this page that isn't a judgement of ours. Headcount moves on demand, offshoring, demographics and the business cycle, and automation is one term among several, often not the loudest.

So a falling line is not evidence that AI did it, and a rising one is not evidence that it won't. Both happen in this register: some occupations resist automation and shrink anyway, others are highly automatable and keep growing. The marked year is 2020.

BLS projection, 2024–2034

-4.3% 54,400 → 52,000 on the projections basis

Exposed, and shrinking

Both signals point the same way: the tasks are largely automatable and the BLS projects -4.3% by 2034. This is the case where the score and the forecast agree, and it is the one worth taking seriously.

Different clocks. The score is what current AI could do to this work today. The projection is how many of these jobs will exist in 2034. Everything between the two — how fast employers actually adopt, whether demand grows in the meantime — is why they can point opposite ways without either being wrong.

~5,400 openings a year on average, including replacing people who leave.

One email if this score changes. Watch as many occupations as you like from the same address — no account, and nothing is sent on a schedule, only when a verdict actually moves.

Also known as — 24 job titles this covers

Titles reported by people doing this work, from the US Department of Labor's O*NET survey. If your job title is here, this page is about your work even though the name doesn't match.

BolterBrewerMasherShakerTapperBlenderFlusherLeacherRiddlerShellerSmutterStemmerTreaterFiltererMaltsterPurifierScreenerStripperSublimerThresherWheelmanClarifierDistillerFermenter

Score — 41/100 resistance

Holding it up: embodiment (15/20). Weakest point: trust premium (3/20).

Five dimensions, 0–20 each, summed. Higher means more protected. The arithmetic is shown so you can check it: 10 + 15 + 5 + 3 + 8 = 41. · Scored 2026-08-11, and re-examined when evidence accumulates rather than on a schedule.

Task resistance 10/20

Mixed — a routine tier and a judgment tier At 10 the split is real: setpoint trimming, flow and temperature logging, and spec-chasing on a distillation column or centrifuge are already handled by DCS loops and advanced process control, while breaking a filter press, replating it, sluicing a plugged bowl, and re-establishing reflux after an upset still needs a body on the deck — roughly half the shift resists, which is why it sits mid-band rather than at 6 or 14.

Embodiment 15/20

Hands-on in uncontrolled environments 15 reflects work done at the equipment, not near it: climbing to sample points on a still, entering a vessel or filter housing under confined-space permit, handling caustic and solvent-wetted media, torquing flanges on hot lines, and doing it on 12-hour rotating shifts in whatever heat, noise, and slurry the plant produces — uncontrolled enough for the upper band but inside a fixed, mapped facility, which keeps it below the 18-20 of field service work.

Liability shield 5/20

Certification preferred, not legally required 5 is the floor plus a nudge: no state licence gates this work, and hiring is HS-diploma-plus-OJT, but process-safety-management sites do require documented operator training under 29 CFR 1910.119, plus HAZWOPER, confined-space, and lockout/tagout certifications — credentials your employer must show a regulator, not credentials that make you personally answerable for a bad batch.

Trust premium 3/20

Anonymous artifact production 3 because the product leaves as clarified liquor, filtrate, or distillate identified by batch number and lab COA — no customer knows which tender ran the column, and your continuity value is to the shift supervisor who trusts your feel for the equipment, not to anyone buying the output.

Judgment & accountability 8/20

Meaningful discretion 8 sits just above procedure-following because the batch sheet, SOP, and alarm limits define most calls, but the ones that matter — deciding a pressure differential means fouling rather than instrument drift, calling for a shutdown before a still runs away, judging whether a filtrate looks off-spec before the lab confirms it — are yours in the minute, and get reviewed afterward by process engineering rather than owned by you.

Confidence: medium · reviewed 2026-08-11 · how scoring works

What this job involves — and which parts are yours

The verdict above describes this occupation as a whole. Almost nobody does the typical version of a job — tick what's actually in your week and see how your own mix sits.

AI already does these at usable quality

These still need a person

Active moats on the surviving side: embodiment, physical-presence

How to future-proof this job

Training paths for your skill gaps: Apprenticeship.gov — industrial maintenance and millwright programs paid to train · Apprenticeship.gov — paid, employer-sponsored trade apprenticeships, searchable by trade and ZIP paid to train · MIT OpenCourseWare — circuits, systems and diagnostic method, free and ungated free · OSHA Outreach Training — the 10- and 30-hour cards most employers ask for low · edX — systems thinking and evaluation methods free to audit · Coursera — negotiation courses, audit free free to audit · Coursera — customer service and client-facing skill courses free to audit

All 35 skills ranked by how many jobs they open →

Where this experience transfers — occupations you could move toward

Computed from U.S. Dept. of Labor O*NET skill and knowledge profiles: high overlap with what you already do, a materially higher resistance score, no large jump in required training, and no licence you would have to start a new pipeline to get. Targets that pay meaningfully less, that are themselves COOKED, or whose own headcount is falling are excluded — a move into a shrinking trade is not an escape.

Industrial Machinery Mechanics SAFE · 67/100 · you already have ~82% of the skill profile

Skills to close: Equipment Maintenance, Repairing, Troubleshooting, Operation and Control

Plant and System Operators, All Other EXPOSED · 57/100 · you already have ~82% of the skill profile

Skills to close: Systems Evaluation, Negotiation, Operation and Control, Service Orientation

Stationary Engineers and Boiler Operators EXPOSED · 64/100 · you already have ~77% of the skill profile

Skills to close: Systems Evaluation

What would move this back up — beyond any one person

The moves above are yours to make. This is the other half: what would have to change in the world for the occupation itself to score higher. None of it is in any one person's gift, but it is where the floor actually comes from. Scores here are not a one-way ratchet. Only two of the five dimensions — task resistance and embodiment — track what machines can do. The other three track law, what buyers will pay for, and who is answerable, and those move in both directions, often in response to the same pressure AI creates. If every lever below landed, this occupation would score around 57/100, still EXPOSED.

5 specific changes that would raise this score
  • already happening embodiment +3

    Sanitary/hazardous process equipment remains manually broken down and cleaned: if pharmaceutical and food plants continue to require CIP verification with human swab sampling and manual disassembly of centrifuge bowls, plate packs and filter housings under FDA cGMP (21 CFR 211.67) and confined-space entry permits under OSHA 1910.146 naming a human entrant and attendant, the physical tier stays non-substitutable regardless of control-room automation

  • already happening task resistance +3

    Task-mix shift: as DCS and predictive process software absorb gauge-reading, logging and setpoint trimming, the residual job concentrates in upset recovery, fouling diagnosis and manual re-start of separators/stills when the model loses the plant — a genuinely two-tier occupation where the remaining tier is troubleshooting

  • plausible liability shield +4

    State-licensed operator requirements extending to process units: e.g. if boiler/steam and wastewater-style operator certification (many states license wastewater and boiler operators by grade, with the certificate holder personally responsible for the shift) is applied to solvent recovery stills and hazardous-waste distillation under RCRA Subpart X or EPA process-unit rules, a named certified human owns the shift log

  • plausible liability shield +3

    cGMP batch record signature discipline: if FDA data-integrity enforcement (Part 11, recent warning letters on unattributed electronic records) is read to require a named human operator's reviewed-by signature on each separation/filtration batch record rather than a system-generated attestation, the sign-off attaches to the operator

  • plausible judgment accountability +3

    PSM-covered units: if OSHA 1910.119 process hazard analysis and management-of-change practice continues to require an operator's authority to abort or manually intervene in a runaway distillation — and insurers (FM Global, Chubb) condition coverage on a qualified human present with stop authority — the consequential-call ownership formally sits with the shift operator

The limit. Trust premium has no realistic route — the buyer buys purified product and never learns who tended the still. Aggregate ceiling is limited: even with licensure, this is commodity production where headcount per unit keeps falling; higher scores would describe fewer, more accountable jobs, not more jobs.

These are conditions, not forecasts — what would have to happen, not what will. Specific rules, cases and bills are named so you can go and check whether they exist and where they stand; verify before relying on any of them. Nothing here is legal or financial advice.

Where this work is, and what it pays there

BLS metro figures for 189 areas. The verdict above does not change by city — the rubric judges what the work involves, not where it happens — but pay and headcount do, and the national median hides a very wide range.

Most of these jobs

Napa, CA 1,400 $64,000 +24%
New York-Newark-Jersey City, NY-NJ 1,140 $59,690 +16%
Modesto, CA 1,000 $73,690 +43%
Denver-Aurora-Centennial, CO 980 $51,180 -1%
Santa Rosa-Petaluma, CA 970 $61,550 +19%
Memphis, TN-MS-AR 930 $50,470 -2%
Riverside-San Bernardino-Ontario, CA 800 $50,150 -3%
Minneapolis-St. Paul-Bloomington, MN-WI 790 $57,700 +12%

Best paid

Syracuse, NY 520 $82,530 +60%
Vallejo, CA 240 $82,440 +60%
Atlanta-Sandy Springs-Roswell, GA 640 $80,140 +55%

Percentages are against this occupation's national median of $51,610. Counts are jobs in that metro, not vacancies. Metros where the BLS suppressed the cell are absent rather than shown as zero.

Who is actually doing this — nobody, on the record

We have no reported case of a named organisation automating this occupation. Not one deployment, not one announcement.

That is worth saying out loud next to a score of 41. The verdict above is about what the work exposes — what current AI could do to these tasks. It is not a claim that anyone has done it. For this occupation those two things have come apart completely: the capability argument is on this page, and the evidence column is empty.

Read that as a gap in the reporting we can see, not proof of absence — the dispatch runs on English-language feeds and misses plenty. If you know of a case, tell us, or add a field report from inside the job.

Quick take — do you do this job?

Has AI actually changed your work? One tap, anonymous, and the running tally is public. Nothing else is asked of you.

Self-reported and unverified — a sentiment signal, not a survey. One response per person per occupation; you can change your answer.

Field reports — what people say has changed

No field reports yet. A written account takes a paragraph rather than a tap, goes to an editor before it appears, and is the one thing on this page the rubric cannot produce on its own.

File a field report

Concrete beats general: a tool that arrived, a task that moved, a headcount decision you watched happen. Don't include anything that identifies you or your employer if that would put you at risk.

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Kept current

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