Metal Shop Image

General Description

The management of hazardous materials used and waste streams generated in metal-working activities for the maintenance of the facility and facility components.

Summary of Federal Requirements

Degreasing Operations

Degreasing is done to remove grease, oils, and/or other dirt etc in order to get a completely clean part. The regulatory impacts of degreasers at federal facilities are outlined in the Vehicle Maintenance -> Degreasers section of the Facility Regulatory Tour.

Hazardous Wastes

The solvent and the debris from a degreaser grit chamber are both usually hazardous waste. This include the "environmentally safe" solvents since once they are used, there is potential for contamination of the solvent such that it would be characterized as a hazardous waste.

Used or spent rags containing listed hazardous wastes or exhibiting hazardous characteristics, are common to many metal shops. Improper management of recyclable or disposable spent rags can result in RCRA penalties for any violator, including federal facilities. A spent rag is one that has been used and is no longer fit for use without being regenerated, reclaimed, or otherwise reprocessed. Perhaps the most important factor in identifying spent rags as hazardous waste is that the sole responsibility lies with the generator or user of the rag. Oil contaminated rags are hazardous based on whether the rags exhibit a characteristic and/or contain a listed material. Whether the rags are shipped off-site for disposal or to an industrial laundry, any accumulation of hazardous rags on-site prior to shipment must be done in compliance with the requirements for the accumulation of hazardous waste rules.

Metal filings generated from metal cutting operations may also be considered a hazardous waste is not disposed of through a scrap metal program. This can also be true of welding stubs.

Metal-working fluids are applied to either the tool or the metal being tooled to facilitate the shaping operation. Fluids resulting from this process typically become spoiled or contaminated with extended use and reuse. When disposed, these fluids may contain high levels of metals (e.g., iron, aluminum, and copper). Be sure that all covers are properly installed on any metal-working machine. In addition to providing worker safety, these covers prevent cutting oils from splashing around the machine and creating additional environmental and health hazards.

Visit the Hazardous Waste Storage section of the Facility Regulatory Tour to find out how to determine if your waste is considered hazardous according to RCRA and what generator classification your facility falls within.

Hazardous Material Storage

Metal Shops use a variety of hazardous materials such as solvents, adhesives, and solder. Depending on the volume of hazardous materials or extremely hazardous materials stored on site, federal facilities must submit notifications of their activities. If the metal shop is a part of a larger facility, the volume of materials is based on the amount of materials total in the larger facility.

The regulatory impacts of hazardous materials stored and/or used at metal shops are outlined in the Laboratories -> Hazardous Materials Storage section of the Facility Regulatory Tour.


Regardless of whether the shop is directly discharging to the environment or to a treatment works, shops performing electroplating, electroless plating, anodizing, coating, chemical etching and milling, and printed circuit board manufacturing are subject to certain best available technology (BAT) point source effluent limitations, which include the self-monitoring of cyanide. Existing metal finishing point sources introducing pollutants into POTWs are subject to certain pretreatment standards. New metal finishing point sources introducing pollutants into POTWs are subject to certain performance and pretreatment standards (40 CFR 433).

If the wastewater is being sent to a sewer authority or Publicly Owned Treatment Works (POTW), visit the Wastewater Treatment Facility -> Discharges to POTW/FOTW section of the Facility Regulatory Tour.

If the wastewater is being directly discharged into the environment, visit the Wastewater Treatment Facility -> Point Source Discharge section of the Facility Regulatory Tour.

Summary of State Requirements

States often require that instructions for the operation of degreaser be posted.

If discharging to a POTW, the POTW may impose pretreatment requirements in addition to the categorical standards.

In a small number of states, the categories of hazardous waste generators are different than those in the federal regulations.

Laws and Statutes

Clean Air Act
Clean Water Act
The Resources Conservation and Recovery Act

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