Managing Hazardous Waste

We strengthen regulations and streamline waste management

Metal Shredding Facilities and Wastes

Project Updates


A Public Workshop was held on June 26, 2018 at the DTSC Sacramento Regional office at Cal Center. Go to our Conditional Exclusion for Chemically Treated Metal Shredder Residue page for more information.

Metal Shredding Report and Feedback

DTSC has completed an extensive analysis of metal shredding facilities, and their processes, wastes, and potential impacts on human health and the environment, pursuant to Senate Bill 1249 (Hill, Statutes of 2015). The analysis was conducted in collaboration with other regulatory agencies that oversee environmental and safety compliance at these facilities, and considered industry compliance with those requirements. It also assessed potential impacts associated with the use of chemically treated metal shredder residue (CTMSR) as alternative daily cover. As part of the evaluation, DTSC sought and considered studies and information from the metal shredding industry and other interested stakeholders. To download the report, click on the link below.

Report: California Department of Toxic Substances Control Evaluation and Analysis of Metal Shredding Facilities and Metal Shredder Wastes 

DTSC appreciates the review by the public and other stakeholders of DTSC’s Draft Evaluation and Analysis of Metal Shredding Facilities and Metal Shredder Wastes (January 2018). DTSC is reviewing each of the comments received, listed below:

Questions can be emailed to:


In 2011, the Department of Toxic Substances Control (DTSC) initiated an evaluation of metal shredding facilities to ensure that their treatment of metal shredder waste for subsequent disposal in solid (nonhazardous) waste landfills was fully protective of human health and the environment. To accomplish this, DTSC requested that five major metal-shredding facilities develop (and ultimately implement) a treatability study work plan that:

  1. Identified the composition and characteristics of metal shredder waste currently being generated
  2. Demonstrated the effectiveness of their current (chemical) treatment methods of metal shredder waste
  3. Evaluated and ultimately identified new treatment methods of metal shredder waste as an alternative to their current treatment methods

To view this industry treatability study work plan and developed from this evaluation process please click here.

As DTSC was working with the metal shredding facilities on their treatability study, Senate Bill (SB) 1249 was introduced in the California Legislature by Senator Hill, based in part on concerns about metal shredder safety due to recent fires at metal shredding facilities in his district, but also in response to the historic concerns about metal shredding facilities, their potential impact on the environment, and DTSC’s past decisions. The provisions of SB 1249 were negotiated with the industry and DTSC and in September 2014, the California legislature enacted SB 1249 (Hill, Chapter 756, Statutes of 2014) requiring metal shredding facilities be thoroughly evaluated and regulated by DTSC to ensure adequate protection of human health and the environment. The law can be found in Health and Safety Code, Division 20, Chapter 6.5, Article 5, sections 25150.82, 25150.84, and 25150.86. To learn more about DTSC’s efforts pursuant to SB 1249, please click here.

What is a Metal Shredding Facility?

California law defines a “metal shredding facility” as an operation that uses a shredding technique to process end-of-life vehicles, appliances, and other forms of scrap metal to facilitate the separation and sorting of ferrous metals, nonferrous metals, and other recyclable materials from non-recyclable materials. A “metal shredding facility” does not include a feeder yard, a metal crusher, or a metal baler, if that facility does not otherwise conduct metal shredding operations. As such, most scrap metal recycling facilities would not be subject to any proposed regulations meant to manage the waste generated from metal shredding facilities. For more information regarding scrap metal recycling facilities, please visit DTSC’s Scrap Metal Recycling page.

What is Metal Shredder Waste?

The shredding of scrap metal (e.g., end-of-life vehicles) results in a mixture of recyclable materials (e.g., ferrous metals and nonferrous metals) and non-recyclable material (i.e., metal shredder waste). Aggregate is generated after the initial separation of ferrous metals, and consists of nonferrous metals which can be further recovered and metal shredder waste. Metal shredder waste consists mainly of glass, fiber, rubber, automobile fluids, dirt and plastics found in automobiles and household appliances that remain after the recyclable metals have been removed. (See Figure 1) Because scrap metal contains regulated hazardous constituents it can contaminate and ultimately cause metal shredder waste to exhibit a characteristic of hazardous waste for toxicity. In a 2002 draft report on auto shredder waste, DTSC showed that metal shredder waste often exceeded the soluble threshold limit concentrations (STLCs) for lead, cadmium and zinc using the Waste Extraction Test (WET) method and the total threshold limit concentration (TTLC) for lead, copper and zinc.

Non-Hazardous Waste Classification Was Granted

Based on the hazardous characteristics of metal shredder waste, in many instances, metal shredding facilities are hazardous waste generators thus subject to hazardous waste requirements, including permitting, transportation and disposal. In the late 80’s, in an effort to relieve metal shredding facilities of these requirements, the Department of Health Services (DHS) (predecessor of the Department of Toxic Substances Control) determined that the metal treatment fixation technologies were capable of lowering the soluble concentrations of metal shredder waste such that the treated metal shredder waste was rendered insignificant as a hazard to human health and safety, livestock and wildlife. Seven metal shredding facilities applied for and were granted nonhazardous waste classification letters by DHS and later DTSC if they used the metal treatment fixation technologies. The authority to issue these classifications is found in subdivision (f) of Section 66260.200 of Title 22 of the California Code of Regulations, and these determinations are now known as “f letters.” These classifications ultimately allowed treated metal shredder waste to be handled, transported and disposed of as nonhazardous waste in class III landfills (i.e., solid (nonhazardous) waste landfills). (See Figure 1)

Metal Shredding Facilities Path to Authorization

DTSC is identifying requirements for environmental protection at metal shredding facilities.  In 2019, DTSC convened a consultation group comprised of community, industry, and regulatory representatives to gather information and perspectives to inform our regulatory path forward. Please see the flowchart below for the consultation process. When DTSC determines the path forward the outcome will be posted on DTSC’s website (here) and also shared at a public meeting hosted by DTSC, to be scheduled.