# Mixing and Blending Machine Setters, Operators, and Tenders

US SOC code 51-9023. Markdown version of https://futurehistory.earth/timeline/51-9023

Also called: Blending operator, Mixer operator, Batch operator, Blender, Compounding operator.

## In brief

In May 2025, [BLS](https://www.bls.gov/oes/special-requests/oesm25nat.zip) counted **94,920** US mixing and blending machine setters, operators, and tenders, with median pay of **$48,990** a year. Of the BLS counts since 2003, the highest was **140,710**, in May 2006. The earliest figure here is [an estimate](https://en.wikipedia.org/wiki/Eleutherian_Mills) of **100** from 1810, not measured the same way as today's count. The current technology era in this work: MES, AI process optimization, and predictive maintenance, since 2015. AI and MES tools reduce the manual sensor-watching and paperwork burden and let fewer operators run more batches, reinforcing the slow employment decline.

## What the sources say

### Official outlook

BLS projects employment to decline 6.1% from 2025 to 2035. Source: [BLS Employment Projections 2025-35](https://data.bls.gov/projections/nationalMatrix?queryParams=51-9023&ioType=o).

### AI exposure studies

- **8.3%** of this job's tasks are exposed to large language models. Not a forecast of job losses. [Eloundou and others, 2023](https://github.com/openai/GPTs-are-GPTs/blob/main/data/occ_level.csv)

Data as of BLS OEWS May 2025; BLS Employment Projections 2025-35. BLS publishes these counts as yearly survey snapshots and cautions against reading them as a precise trend. In May 2021 BLS changed how it estimates these counts (a model-based method using three years of survey data) and moved fully to the 2018 occupation codes, so part of a change across 2021 can come from the method rather than the work.

## Mixing and Blending Machine Setters, Operators, and Tenders employment and pay by year

- On record since: 1802
- Latest US employment: 94,920 (May 2025). Source: BLS OEWS May 2025 [5]
- Latest US median pay: $48,990 (May 2025). Source: BLS OEWS May 2025 [7]
- Outlook: -6.1% by 2035. Source: BLS Employment Projections 2025-35 [17]

### All 27 years of cited US data

| Year | US employment | Annual pay (median unless marked) | Source |
| --- | --- | --- | --- |
| 1810 | 100 (estimate) | n/a | Est., Wikipedia [1] |
| 1880 | 5,000 (estimate) | n/a | Est., Centre Colours [2] |
| 1950 | 90,000 | n/a | Decennial Census 1960 [3] |
| 2000 | 111,480 | $25,000 (estimate) | BLS OEWS 2000 (employment) [4]; Est., O\*NET 51-9023.00 (pay) [6] |
| 2003 | 106,610 | $27,940 | BLS OEWS May 2003 [5] |
| 2004 | 119,320 | $28,110 | BLS OEWS May 2004 [5] |
| 2005 | 129,440 | $28,890 | BLS OEWS May 2005 [5] |
| 2006 | 140,710 | $29,330 | BLS OEWS May 2006 [5] |
| 2007 | 139,370 | $30,340 | BLS OEWS May 2007 [5] |
| 2008 | 140,120 | $31,280 | BLS OEWS May 2008 [5] |
| 2009 | 129,250 | $32,090 | BLS OEWS May 2009 [5] |
| 2010 | 123,840 | $32,870 | BLS OEWS May 2010 [5] |
| 2011 | 118,700 | $33,590 | BLS OEWS May 2011 [5] |
| 2012 | 117,210 | $33,840 | BLS OEWS May 2012 [5] |
| 2013 | 117,390 | $33,960 | BLS OEWS May 2013 [5] |
| 2014 | 122,670 | $34,340 | BLS OEWS May 2014 [5] |
| 2015 | 129,270 | $34,600 | BLS OEWS May 2015 [5] |
| 2016 | 130,480 | $35,680 | BLS OEWS May 2016 [5] |
| 2017 | 129,490 | $36,600 | BLS OEWS May 2017 [5] |
| 2018 | 128,600 | $37,210 | BLS OEWS May 2018 [5] |
| 2019 | 125,340 | $37,780 | BLS OEWS May 2019 [5] |
| 2020 | 116,190 | $38,690 | BLS OEWS May 2020 [5] |
| 2021 | 108,440 | $38,420 | BLS OEWS May 2021 [5] |
| 2022 | 108,900 | $43,410 | BLS OEWS May 2022 [5] |
| 2023 | 105,740 | $46,100 | BLS OEWS May 2023 [5] |
| 2024 | 100,840 | $47,680 | BLS OEWS May 2024 [5] |
| 2025 | 94,920 | $48,990 | BLS OEWS May 2025 [5] |

## Sources (79)

### Employment series

1. [Wikipedia — Eleutherian Mills (DuPont Brandywine gunpowder works, founded 1802; mixing-house operations and the 1818 explosion)](https://en.wikipedia.org/wiki/Eleutherian_Mills), Wikipedia
2. [Centre Colours — "Historical facts about the evolution of paint" (steam-powered paint mills and roller mills from the late 1870s; mechanization of grinding and mixing)](https://www.centrecolours.co.uk/historical-facts-about-the-evolution-of-paint), Centre Colours
3. [IPUMS USA — 1960 Occupation Codes (operatives and kindred workers classification; mixing/blending operatives in manufacturing)](https://usa.ipums.org/usa/volii/96occup.shtml), IPUMS / University of Minnesota
4. [BLS OES 2000 national estimates (flat file)](https://www.bls.gov/oes/special-requests/oes00nat.zip), Bureau of Labor Statistics
5. BLS OEWS, national cross-industry estimates (flat file), Bureau of Labor Statistics. Editions: [2003](https://www.bls.gov/oes/special-requests/oesm03nat.zip), [2004](https://www.bls.gov/oes/special-requests/oesm04nat.zip), [2005](https://www.bls.gov/oes/special-requests/oesm05nat.zip), [2006](https://www.bls.gov/oes/special-requests/oesm06nat.zip), [2007](https://www.bls.gov/oes/special-requests/oesm07nat.zip), [2008](https://www.bls.gov/oes/special-requests/oesm08nat.zip), [2009](https://www.bls.gov/oes/special-requests/oesm09nat.zip), [2010](https://www.bls.gov/oes/special-requests/oesm10nat.zip), [2011](https://www.bls.gov/oes/special-requests/oesm11nat.zip), [2012](https://www.bls.gov/oes/special-requests/oesm12nat.zip), [2013](https://www.bls.gov/oes/special-requests/oesm13nat.zip), [2014](https://www.bls.gov/oes/special-requests/oesm14nat.zip), [2015](https://www.bls.gov/oes/special-requests/oesm15nat.zip), [2016](https://www.bls.gov/oes/special-requests/oesm16nat.zip), [2017](https://www.bls.gov/oes/special-requests/oesm17nat.zip), [2018](https://www.bls.gov/oes/special-requests/oesm18nat.zip), [2019](https://www.bls.gov/oes/special-requests/oesm19nat.zip), [2020](https://www.bls.gov/oes/special-requests/oesm20nat.zip), [2021](https://www.bls.gov/oes/special-requests/oesm21nat.zip), [2022](https://www.bls.gov/oes/special-requests/oesm22nat.zip), [2023](https://www.bls.gov/oes/special-requests/oesm23nat.zip), [2024](https://www.bls.gov/oes/special-requests/oesm24nat.zip), [2025](https://www.bls.gov/oes/special-requests/oesm25nat.zip)

### Wage series

6. [O\*NET 51-9023.00 — BLS-sourced occupation summary (early-2000s wage reference for 51-9023)](https://www.onetonline.org/link/summary/51-9023.00), O\*NET / BLS
7. BLS OEWS, national cross-industry estimates (flat file), Bureau of Labor Statistics. Editions: [2003](https://www.bls.gov/oes/special-requests/oesm03nat.zip), [2004](https://www.bls.gov/oes/special-requests/oesm04nat.zip), [2005](https://www.bls.gov/oes/special-requests/oesm05nat.zip), [2006](https://www.bls.gov/oes/special-requests/oesm06nat.zip), [2007](https://www.bls.gov/oes/special-requests/oesm07nat.zip), [2008](https://www.bls.gov/oes/special-requests/oesm08nat.zip), [2009](https://www.bls.gov/oes/special-requests/oesm09nat.zip), [2010](https://www.bls.gov/oes/special-requests/oesm10nat.zip), [2011](https://www.bls.gov/oes/special-requests/oesm11nat.zip), [2012](https://www.bls.gov/oes/special-requests/oesm12nat.zip), [2013](https://www.bls.gov/oes/special-requests/oesm13nat.zip), [2014](https://www.bls.gov/oes/special-requests/oesm14nat.zip), [2015](https://www.bls.gov/oes/special-requests/oesm15nat.zip), [2016](https://www.bls.gov/oes/special-requests/oesm16nat.zip), [2017](https://www.bls.gov/oes/special-requests/oesm17nat.zip), [2018](https://www.bls.gov/oes/special-requests/oesm18nat.zip), [2019](https://www.bls.gov/oes/special-requests/oesm19nat.zip), [2020](https://www.bls.gov/oes/special-requests/oesm20nat.zip), [2021](https://www.bls.gov/oes/special-requests/oesm21nat.zip), [2022](https://www.bls.gov/oes/special-requests/oesm22nat.zip), [2023](https://www.bls.gov/oes/special-requests/oesm23nat.zip), [2024](https://www.bls.gov/oes/special-requests/oesm24nat.zip), [2025](https://www.bls.gov/oes/special-requests/oesm25nat.zip)

### Tool eras

8. [Wikipedia — Eleutherian Mills (DuPont Brandywine mixing house; hand-blended gunpowder; blast-wall mill design)](https://en.wikipedia.org/wiki/Eleutherian_Mills), Wikipedia
9. [Centre Colours — "Historical facts about the evolution of paint" (hand grinding with muller and slab; pug mills; pre-machinery paint mixing)](https://www.centrecolours.co.uk/historical-facts-about-the-evolution-of-paint), Centre Colours
10. [Wikipedia — Industrial process control (early relay-logic and single-loop control of batch and continuous processes)](https://en.wikipedia.org/wiki/Industrial_process_control), Wikipedia
11. [Wikipedia — Programmable logic controller (Modicon 084, 1969; the first PLC, built for General Motors)](https://en.wikipedia.org/wiki/Programmable_logic_controller), Wikipedia
12. [The Automation Blog — "Control System Changes Over The Last Five Decades" (Honeywell TDC-2000, 1975; first distributed control system)](https://theautomationblog.com/last-five-decades-of-controls/), The Automation Blog
13. [Wikipedia — ISA-88 (batch control standard first published 1995; recipe, batch, and equipment-module models; developed with Bayer, DuPont, P&G)](https://en.wikipedia.org/wiki/ISA-88), Wikipedia
14. [MXD Process — "Automated vs. Manual Mixing Systems" (HMI/SCADA recipe control versus manual batch operation in modern mixing plants)](https://www.mxdprocess.com/blog/automated-vs-manual-mixing-systems), MXD Process
15. [IoT Analytics — "State of Digital in Process Manufacturing 2025" (adoption of AI, MES, and predictive analytics in batch process plants)](https://iot-analytics.com/state-of-digital-in-process-manufacturing/), IoT Analytics
16. [Siemens — AI Process Optimization for Food and Beverage (automated deviation detection on mixing/process sensor streams)](https://www.siemens.com/en-us/industries/consumer-packaged-goods/food-beverage/ai-process-optimization/), Siemens

### Forecasts and exposure studies

17. [BLS Employment Projections 2025-35, National Employment Matrix: 51-9023 Mixing and blending machine setters, operators, and tenders (2025: 97.3 thousand; 2035: 91.4 thousand; -6.1%)](https://data.bls.gov/projections/nationalMatrix?queryParams=51-9023&ioType=o), Bureau of Labor Statistics
18. [Eloundou, Manning, Mishkin & Rock (2023), "GPTs are GPTs", occupation-level exposure data occ\_level.csv (O\*NET-SOC 51-9023.00, human-rated β 0.083)](https://github.com/openai/GPTs-are-GPTs/blob/main/data/occ_level.csv), OpenAI

### Historical notes

19. [Wikipedia — Eleutherian Mills (the 1818 explosion at the DuPont gunpowder works)](https://en.wikipedia.org/wiki/Eleutherian_Mills), Wikipedia
20. [Wikipedia — Programmable logic controller (Modicon 084, 1969, the first PLC)](https://en.wikipedia.org/wiki/Programmable_logic_controller), Wikipedia
21. [Wikipedia — ISA-88 (batch control standard, first published 1995)](https://en.wikipedia.org/wiki/ISA-88), Wikipedia
22. [O\*NET 51-9023.00 — occupation summary (2000 SOC introduction of the 51-9023 code)](https://www.onetonline.org/link/summary/51-9023.00), O\*NET / BLS

### Predecessors & successors

23. [Wikipedia — Eleutherian Mills (DuPont mixing-house powdermen, 1802 onward)](https://en.wikipedia.org/wiki/Eleutherian_Mills), Wikipedia
24. [Centre Colours — "Historical facts about the evolution of paint" (colormen grinding and mixing pigment by hand and on early mills)](https://www.centrecolours.co.uk/historical-facts-about-the-evolution-of-paint), Centre Colours
25. [IPUMS USA — 1960 Occupation Codes (operatives and kindred workers in manufacturing)](https://usa.ipums.org/usa/volii/96occup.shtml), IPUMS / University of Minnesota
26. [O\*NET 51-9023.00 — related occupations and career pathways for mixing and blending operators](https://www.onetonline.org/link/summary/51-9023.00), O\*NET / BLS

### Present-day analysis

- [O\*NET 29.0 — Mixing and Blending Machine Setters, Operators, and Tenders (51-9023.00)](https://www.onetonline.org/link/summary/51-9023.00), accessed 2026-06-05
- [BLS Occupational Outlook — Miscellaneous Production Workers, 2024](https://www.bls.gov/ooh/production/miscellaneous-production-workers.htm), accessed 2026-06-05
- [Eloundou et al. 2024 — GPTs are GPTs: Labor Market Impact Potential of LLMs (Science)](https://arxiv.org/abs/2303.10130), accessed 2026-06-05
- [IoT Analytics — State of Digital in Process Manufacturing 2025](https://iot-analytics.com/state-of-digital-in-process-manufacturing/), accessed 2026-06-05
- [MXD Process — Automated vs. Manual Mixing Systems](https://www.mxdprocess.com/blog/automated-vs-manual-mixing-systems), accessed 2026-06-05
- [AspenTech — Refinery Multi-Blend Optimizer](https://www.aspentech.com/en/products/msc/aspen-refinery-multi-blend-optimizer), accessed 2026-06-05
- [AspenTech OPTIMIZE 26 Innovations Preview](https://www.emerson.com/en/corporate/news/2026/aspentech-optimize26-to-showcase-innovative-technologies), accessed 2026-06-05
- [Siemens AI Process Optimization for Food and Beverage](https://www.siemens.com/en-us/industries/consumer-packaged-goods/food-beverage/ai-process-optimization/), accessed 2026-06-05
- [Factory AI — AI Predictive Maintenance Use Cases in Food Manufacturing 2025](https://f7i.ai/blog/from-compliance-to-competitiveness-11-ai-predictive-maintenance-use-cases-transforming-food-manufacturing-in-2025), accessed 2026-06-05

How to read these figures: https://futurehistory.earth/methodology. Every figure links to its own source; gaps stay gaps.