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Metal Fabrication & Machining: Reasons for Change
Table of Contents
Background and Overview
Reasons for Change
P2 Opportunities
Assistance Activities
Where To Go for Help
Complete List of Links

Essential Links:

An Analysis of Pollution Prevention Opportunities and Impediments in the Fabricated Metal Products M...
Identifies the specific causes of waste generation and cost-effective solutions to reduce waste in t...

Do Your Fluids Contain Chlorine?
Guidance for determining if your metal working fluids contain chlorine and disposal implications.

Metal Fabrication Industry - Compliance and Pollution Prevention Workbook
Provides information on assessing the processes for environmental impact and pollution prevention op...

Metal Machining Sector: Pollution Prevention Assessment and Guidance
This report provides technical and regulatory information for the metal machining industry sector.

Metal Working Fluids: A Resource for Employers and Health & Safety Personnel In Washington State
Describes the different metal working fluids used in machining and the potential health effects.

Metalworking Fluids: A Fact Sheet for Workers
Explains how workers' health is affected by exposure to metalworking fluids.

Mycobacterium sp. as a Possible Cause of Hypersensitivity Pneumonitis in Machine Workers
This study supports the hypothesis that aerosolized mycobacteria colonizing metal removal fluids lik...

Profile of the Metal Fabrication Industry
Provides a summary of industrial process, pollution outputs, pollution prevention, and regulations a...

Regulatory Overview (excerpts from NEWMOA's P2 in Machining and Metal Fabrication Industry manual)
Overview of federal environmental regulations and Northeast states P2 laws affecting machinists and...

The Spectrum of Respiratory Disease Associated with Exposure to Metal Working Fluids
A report of respiratory illnesses occurring in an outbreak in 30 workers of an automobile parts engi...

Environmental Compliance
To an extent, all industrial processes have pollution issues and waste streams. For the most part, metal fabrication processes do not generate wastes as hazardous as those produced by other processes involved in the manufacturing of complex metal parts (i.e., metal finishing or metal coating). However, cutting and shaping processes may generate significant volumes of spent metalworking fluid, which require proper storage, handling, manifesting and overall management. Other processes, such as salt bath heat treating, brazing, and soldering, may generate wastes that are regulated under wastewater, air, or hazardous waste regulations.

Fabrication processes that are the most heavily regulated include:

  • copper forming
  • aluminum forming
  • nonferrous metal forming
  • cyanide salt bath heat treating
  • soldering with cadmium-containing solders
  • solvent-based adhesive processes

For information on regulations that affect metal finishing, metal coating visit the Metal Finishing Topic Hub.

Common Wastes in Metal Fabrication Facilities
Metal fabrication facilities vary greatly in size and operation. In metal shaping and cutting operations, the generation of spent metalworking fluids and scrap metal are the two major waste streams. Other processes in the fabrication of metal parts may have significantly more toxic or hazardous byproducts. This section will define the common sources of wastewater, solid and hazardous waste, and air emissions generated from metal fabrication operations. This section also will briefly discuss worker health and safety impacts from using metalworking fluids.

Most metal fabricating facilities generate a variety of wastewater streams. Some of the typical sources are water-based metalworking fluids, non-contact cooling water, interim rinse tanks in quenching processes, boiler blow-down water, wet deburring, waterjet cutting, welding quench tanks, and scrubbers. Metalworking fluids are generally handled as hazardous or state regulated oily waste because they contain hazardous constituents and fail fat, oil, and grease (FOG) limits of publicly owned treatment works (POTWs). The contaminants that some of the other process fluids pick up may also make them unsuitable for discharge, and they are often shipped offsite for treatment and disposal through a licensed hauler.

Stormwater is affected mainly from storing raw materials, hazardous wastes and equipment outside. Sheet metal and steel plate often has oily residue from lubricants and machine coolants used at the mill. These oils can wash off when exposed to rain and storm water run-off. Some states have regulations that require control of stormwater runoff from industrial properties.

Solid and Hazardous Waste
In metal fabrication processes, process fluids that become excessively contaminated are periodically changed and disposed of. Process fluids are shipped off-site for disposal or treatment. Process fluids are usually considered a hazardous material, although in some states, if handled appropriately, they can be exempted. The following are common examples of hazardous waste from metal fabrication operations:

  • spent metalworking fluids that cannot be treated in process or have been biologically degraded
  • spent salt baths from heat treating processes
  • spent quenchant
  • tank dredges
  • spent filter media
  • flux baths from certain soldering operations
  • scrubber wastes containing hazardous salts and metalworking fluids

Scrap metal, chips, and swarf are common solid wastes from metal fabrication processes that may require special handling depending on how much metalworking fluid they contain. It is often necessary to reduce the amount of metalworking fluid in these waste streams before a scrap dealer will accept them. Oil contaminated rags and absorbents are other common wastes whose handling also is dictated by how much metalworking fluid they contain. Regulations covering waste oil and spent rags can vary greatly from state to state; for state-specific information contact your state environmental agency's waste management program.

Metal fabrication facilities generate solid waste in the form of broken pallets, cardboard boxes, and other packaging and shipping materials. Many of these waste streams may be recycled and facilities have set up separation programs to divert as much as possible from the solid waste stream to reduce waste disposal costs.

Air Emissions
The use of metal working fluids in metal shaping and metal removal processes may result in fugitive emissions in the form of smoke, mist, or vapor. Other processes may create more hazardous air emissions. Possible sources of air emissions in metal fabrication processes are:

  • smoke emissions from metal removal processes
  • potential VOC emissions from metalworking fluids
  • metalworking fluid mists
  • cyanide emissions from salt baths
  • evaporating metalworking fluids from salt baths and furnaces
  • evaporative losses of solvents from adhesive processes
  • vaporized solder fluxes

Regulatory requirements on the above emissions vary depending on the specific application and location. For specific information on regulatory requirements related to these sources, contact your state environmental agency's air quality program.

Worker Health and Safety
Worker health and safety can be compromised by some of the processes and activities at machine and metal fabrication shops. The most common paths of exposure to workers is by inhaling or having skin contact with metalworking aerosols, chemical constituents, oils, contaminated fluid and biocides that are found in common metalworking fluids.

In 1998, the National Institute for Occupational Safety and Health (NIOSH) recommended a new standard specifically for metalworking fluid aerosols. The standard was proposed because workers currently exposed to metalworking fluid aerosols at current limits have an increased risk of nonmalignant respiratory disease and skin disease. Some adverse health effects related to metalworking fluids are:

  • Dermatitis (skin rash), oil acne, allergic contact dermatitis
  • Cancer (unclear whether formulation changes made in the 1950's have eliminated the cancer risk)
  • Reduction in lung function and increase in lung diseases (asthma, acute airway irritation, hypersensitivity pneumonitits, lipid pneumonia, chronic bronchitis)
  • Irritation to eyes, nose and throat

NIOSH identified the following selected chemicals and contaminants that pose health risks to workers:

  • Chemical ingredients and additiviies: triethanolamine, mineral oil, antimicrobial agets, chlorinated paraffins, and potetntial sensory or pulmonary irritants
  • Contaminants: nitrosamines, microbes, metals and metal alloys

Costs of Managing Waste Streams
Using raw materials and processes that have an environmental impact are very costly. Most often, businesses usually only account for waste disposal costs rather than considering all of the associated costs with operating inefficient equipment and using toxic raw materials.

The following table shows the different categories of costs associated with simply being in compliance and those costs incurred that are typically accounted for as oversight. Considering all of the costs associated with wasteful practices motivate a business to change.

Compliance Costs Oversight Costs

Receiving Area

Spill response equipment
Emergency response plan

Raw Materials Storage

Storage facilities
Secondary containment
Right-to-know training
Reporting and records
Safety training
Container labels
Process Area
Safety equipment
Right-to-know training
Waste collection equipment
Emission control equipment
Sampling and Testing
Reporting and records

Solid and Hazardous Waste

Sampling and Testing
Labels and labeling
Storage areas
Transportation Fees
Disposal fees

Air and Water Emissions Control

Permit preparation
Permit fees
Capital costs
Operating expenses
Recovered materials
Inspection and monitoring
Recording and reporting
Sampling and testing
Emergency planning
Discharge fees


Product/vendor Research
Regulatory impact analysis
Inventory control


Hazard analysis
Sampling and testing


Employee training
Emergency planning
Medical monitoring
Waste collection
Disposal management
Inspections and audits


Public relations


Regulatory research
Legal fees
Information systems
Penalties and fines


Credit costs
Tied-up capital


The Topic Hub™ is a product of the Pollution Prevention Resource Exchange (P2Rx)

The Metal Fabrication & Machining Topic Hub™ was developed by:

Northeast Waste Management Officials' Association
Northeast Waste Management Officials' Association
Contact email:

Hub Last Updated: 12/4/2012