HWTR Dangerous Materials

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Spent Antifreeze

Spent antifreeze is a common toxic substance. Ethylene glycol antifreeze has a special regulatory status in Washington state. Antifreeze should always be recycled.  If it is not recycled, it must either be proven to be safe (rare), or handled as dangerous waste, subject to full regulation.

Recycled antifreeze can be found in the Dangerous Waste Regulations at WAC 173-303-522.

The Dangerous Waste Regulations encourage the recycling of spent antifreeze. It is a "state-only" waste, due to its toxicity after use. However, if antifreeze is recycled, it may be exempt from most dangerous-waste regulations. It will not be counted toward generator status. 

Some antifreeze sludges and filters from self-recyclers may still be dangerous waste, but businesses who collect antifreeze for a vendor to recycle only need to follow a few simple handling procedures detailed in the information below.

However, exemptions from the dangerous waste regulations require that antifreeze be recycled properly. 

Recycle On- or Off-site

Sometimes antifreeze is recycled on-site through reuse, distillation, filtration or ion exchange. On-site recyclers should note that filters from an antifreeze-recycling machine probably designate as dangerous waste. Also, dangerous-waste sludges must be tracked and properly disposed of off-site.  Many send antifreeze off-site for recycling through a vendor. In some areas, a mobile recycling unit may travel to facilities.

Contain and Label Spent Antifreeze

Suitable containers for spent antifreeze may include metal or plastic barrels or jugs, in good condition.  Lids must be in place at all times, except when adding or removing waste.  Keep waste antifreeze free from cross-contamination with other wastes, including used oil, fuels, degreasers, or radiator flush chemicals. Keep used antifreeze equipment (funnels, pads, storage containers) separate from equipment used in other waste.

Secondary containment is essential, because antifreeze is a liquid.

All containers of spent antifreeze waiting to be recycled must have a "spent antifreeze" label and a risk label reading "toxic."  If reusing empty containers, remove or obliterate old labels and re-label. 

Spent Antifreeze labels are near the top of this page.

Keep Antifreeze Recycling Records

Those who generate antifreeze for recycling must keep good records. See the chart below for the types of information that inspectors will need to see.

Where Recycled

Records Needed (Keep for 5 years.)


Record recycling activity: amount of antifreeze recycled, when, weight of dangerous-waste filters, and sludge shipped off-site.  Optional form offered: On-site Antifreeze Recycling Log (pdf)


Record amount of spent antifreeze sent for recycling, when shipped, and to whom


Record amount of antifreeze recycled, by whom, and when.

Off-site and mobile recycling vendors may provide all the information on their receipts. If you are shipping the antifreeze off-site to be recycled, save your bills of lading, receipts, and any manifests for five years, so that you can prove your recycling activity.  You must keep these receipts for five years, however. Keep them accessible for inspections.  

If you have an on-site recycling machine, log the amount of antifreeze that is being recycled each month. 

On-site Antifreeze Recycling Log (pdf) offers an optional form that may be used to keep on-site recycling records. 

Prevent or Report Spills

Spill kits and spill plans are an important part of protecting nearby streams and sometimes, even, the safety and health of workers.  Keep spill-control equipment in a central location, accessible to employees. Train employees to use it.

Transport Spent Antifreeze

If a business transports its own antifreeze off-site for recycling, they do not have to have any special shipping papers. Spent antifreeze can be self-transported for reclamation without the need for a RCRA Site Identification number or license.

Those who transport spent antifreeze generated by others will need to keep paperwork.  The shipping papers will need to include the following language: “Material not regulated by DOT (Washington State Dangerous Waste Only, Toxic).”

Prevent pollution from antifreeze

Drain antifreeze from radiators and heater cores as soon as possible. Keep volumes of spent antifreeze low by properly and routinely recycling the waste.

Propylene Glycol is a less-toxic alternative to the more-common Ethylene Glycol antifreeze.  This helps to prevent poisonings in children and pets. However, it is still usually a dangerous waste when it is spent, because heavy metal contaminates it when it is used.  Propylene glycol must be recycled separately from the ethylene glycol antifreeze.

ToxFAQs for Ethylene Glycol from the Agency for Toxic Substances and Disease Registry at the Centers for Disease Control

Ethylene Glycol and Propylene Glycol Toxicity Case Studies in Environmental Medicine from the Agency for Toxic Substances and Disease Registry


Related information

Focus on Spent Antifreeze is an Ecology publication that details the counting exemption for antifreeze and talks about three ways to recycle it. 

Special requirements for recycling spent antifreeze is in the Dangerous Waste Regulations at WAC 173-303-522.

Waste Antifreeze Characterization Study describes a 1991 study that tested antifreeze for toxic components.

Shop Guide for Dangerous Waste Management is an Ecology guide to handling many types of common shop wastes, including antifreeze.

Auto Body Pilot Technical Assistance Manual contains antifreeze information.

Antifreeze Recycling (pdf) is a publication from California's Department of Toxic Substances Control that offers explanation of the recycling process.