How Oil Mist is Produced

October 6, 2020

What is oil mist?

Oil mist produced from metalworking processes like CNC machiningIt’s that greasy film you’ve noticed building up on machinery. Oil mist is a byproduct of using metalworking fluids (MWFs) in an industrial machining or cutting process.

Is oil mist a problem?

Yes and no. Oil mist is an inevitable byproduct of using MWFs. While it can be captured at the source, liquid mist will always find a way to leak out — usually through ductwork seams or joints. Most facilities know it’s a nuisance but have come to accept it as a part of manufacturing or production that requires regular cleaning and maintenance. Although MWFs can prolong the tools’ lives and make it easier to cut through materials, the oil mist they produce can also pollute the manufacturing space and overload collectors.

What causes oil mist?

Machining mist resulting from metalworking

Processes like cutting, grinding, turning, or milling require MWFs and generate machining mist. While the fluid is essential to the machine’s efficiency, it produces oil mist that can cause electrical damage, corrode metal, and pose a slipping hazard if there’s an excess build up on the machines or floors. Even worse, oil mist often contains cancer-causing agents and can cause eye, throat, and lung irritation.

Aerosols — not just a metalworking problem

Oil mist is a metalworking problem, but other leaking effluents are just as harmful. Fluids escaping or produced by other processes can significantly impact air quality, safety, and operations.


Plasticizers can make material more flexible and durable. They are often seen in plastic and PVC production and found in vinyl flooring, adhesives, and detergents. Although plasticizers don’t pose much of a health threat to end-users, plasticizers may irritate the lungs or throat if inhaled during production.

Parts Washing

Parts washing creates a wet, misty byproduct that needs to be collected and funneled away from the process. At high temperatures, parts washing makes excess steam and heat in a work environment that can damage surrounding work stations, be dangerous to personnel, and increase the costs of cooling the facility.

Solutions to oil mist collection

Capturing and exhausting leaking oil mist just requires the right tools. Many cutting and milling machines are equipped with collectors or eliminators to control oil mist at the source.

However, these solutions don’t trap all of the oil mist, and most ductwork carrying liquid, mist-like byproducts will leak. Airtight ductwork is essential to controlling and exhausting leaking oil mist or another byproduct. An inline oil mist accumulator is often used and can reduce the amount of effluent that reaches the collector.

US Duct manufactures oil mist curbs, oil mist accumulators, and a line of airtight ducting (US Tubing) that help manage oil mist. The torque-tightened clamp and full gasket system make US Tubing an airtight — and mist-tight — solution for maintaining efficient processes and a clean facility. Reach out to a Duct Guy today to discuss your ductwork application and the best solution.

Manage-oil-mist-like-a-proGot leaks?

Everyone does. But not everyone knows how to handle them.

With the right knowledge and tools, anyone can mitigate the risks associated with leaky ductwork. Our guide takes you through what to consider — from common causes to the most secure connections — for effectively managing leaks and maintaining safe, healthy work environments.

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