Chemical Plant and System Operators

Mixed — a routine tier and a judgment tier. Advanced process control already holds the loops, ramps rates and writes the shift log, but nobody has automated a cold startup from a turnaround, a manual bypass lineup around a fouled exchanger, or diagnosing why a column is flooding when the level transmitter reads fine — that split of the day is what sits it at 12 rather than 6 or 16.

Hands-on in uncontrolled environments. Climbing structures to gag a relief valve, breaking flanges for line-breaking permits, pulling grab samples off a hot header in a fire-retardant suit and respirator, and swapping pumps in weather and H2S monitoring range is uncontrolled physical work at 16; it stops short of 20 because a real share of the shift is genuinely spent seated at the console.

Certification preferred, not legally required. There is no state operator licence for chemical units the way there is for boilers or wastewater — what you carry is HAZWOPER, RCRA, DOT and unit-specific qualification cards plus your name on the permit and the log, so PSM (29 CFR 1910.119) liability lands on the employer's process-safety program, not on you personally, which is why this is a 7 and not an 11.

Some relationship component. Your reputation matters to the incoming shift and the unit supervisor at handover — they weigh whether your notes on a sticking valve are reliable — but the customer buying the product never learns your name, and any qualified operator on the board can run the unit, which caps this near the bottom of the relationship band.

Meaningful discretion. When a compressor trips at 3 a.m. and you have minutes to decide whether to route to flare, initiate emergency depressurization or ride it out, procedures narrow the choice but do not make it for you, and misreading a runaway exotherm is a fatality event — 13 rather than 16 because the written operating and emergency procedures and a callable engineer or supervisor cover most abnormal cases.