Revision Date: 11/03
Process Code: Navy/Marines: IND-010-00; Air Force: RR-01; Army: MTF
Usage List: Navy: Medium; Marines: Medium; Army: Medium; Air Force: Medium
Alternative For: Single use of metal working fluids
Compliance Impact: Medium
Applicable EPCRA Targeted Constituents and CAS Numbers: N/A

Overview: Generation of waste metal-working fluids can be minimized by extending the useful life of the fluids. Metal-working fluid life is a function of various factors including: type of metal working operation, type/quality of fluid used, housekeeping practices, contamination, bacterial contamination, and water quality.

Spent metal-cutting fluids may be considered hazardous wastes due to the products’ formulation or by absorbing contaminants through metal working operations. Under 40 CFR Part 279, Used Oil Management Standards, used oil is defined as oil refined from crude (or any synthetic oil) used as a lubricating, hydraulic, or heat transfer fluid  that has become contaminated through use. Coolants may be managed under these regulatory provisions and recycled as opposed to disposed. Extending the fluid life by maintaining its cleanliness is a practical means of reducing a hazardous waste stream.

Modular systems are available for on-site, batch recycling of metal working fluids. These systems clean the fluids by removing solids, bacteria, and tramp oil contaminants. These systems may incorporate filtration, centrifugation, pasteurization, oil skimming, and/or coalescence processing steps. Water or fluid concentrate may be added to the reclaimed fluid to adjust the fluid concentration to the desired level. The fluids are then returned to the machine sump(s).

Milacron markets modular systems for collection, treatment, and recycling of metal working fluids. One such unit was used for short time at the Naval Shipyard in Portsmouth, New Hampshire. The capital costs for a fluid collection device and recycle module would start at around $40,000.

An alternative to purchase, operation, and maintenance of recycling equipment by the shop is the use of mobile recycling services, such as Fluid Recycling Services. These services utilize similar processing steps to those described above to treat metal working fluids on-site on a periodic basis. There is typically a minimum charge per visit plus a rate per gallon of fluid treated.

For shops that generate less than 25 tons/yr. of waste cutting oil, or less than 45 tons/yr. of waste soluble oil machine coolant, a mobile fluid recycling service would probably be the preferred arrangement. For shops that generate larger amounts of waste metal working fluids, purchase of in-house recycling equipment should be considered. For either option, the economics of recycling metal working fluids are improved by minimizing the number of different metal working fluids used in one shop.

Compliance Benefit: Recycling of cutting oil may allow the used oil to fall under the less stringent regulations of 40 CFR 279 as opposed to the hazardous waste regulations in 40 CFR 260 through 268. In addition, under 40 CFR 261.5, generators that recycle their used oil and manage it under 40 CFR 279 do not have to count the used oil into their monthly totals of hazardous waste generated. This may help facilities to meet the requirements of waste reduction under RCRA, 40 CFR 262 and Executive Order (EO) 13148. The decrease in the quantity of hazardous waste generated monthly may also help a facility reduce their generator status and lessen the amount of regulations (i.e. recordkeeping, reporting, inspections, transportation, accumulation time, emergency prevention and preparedness, emergency response) they are required to comply with under RCRA, 40 CFR 262. Recycling of used oil generally requires a facility to store large quantities of used oil on site. A Spill Prevention, Control and Countermeasure Plan is required to be developed and implemented under 40 CFR 112 for facilities that store certain amounts of oil on site. Finally, due to the reduced amounts of cutting oil stored on site, a facility may decrease the likelihood of meeting reporting thresholds under SARA Title III (40 CFR 300, 355, 370, and 372).

The compliance benefits listed here are only meant to be used as general guidelines and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g., the amount of workload involved.

Materials Compatibility: No materials compatibility issues have been identified.

Safety and Health: Mild skin and eye irritation effects are associated with these compounds. Personal protective equipment should be used. Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing this technology.

  • Potential of a 50 percent reduction in cutting fluid hazardous waste stream.
  • Reduced purchase of new metal working fluids.

  • Requires more careful monitoring of cutting fluid quality.
  • For smaller shops, off-site recycling services may be more cost effective.

Economic Analysis: The following example is for a facility that generates a fairly large quantity of spent cutting fluid (3,000 gallons per year). Most facilities will generate less than this amount thus extending the potential payback period. For smaller shops, off-site recycling services may be more cost effective. The cost for fresh cutting fluid is based on vendor information. An economic analysis comparing on-site cutting fluid recycling versus disposal can be found on datasheet 6-I-8 Cutting Fluid Recycler.


  • Mobile recycler recycles the cutting fluid on-site.
  • Cutting fluids that are sent off-site for recycling are handled at no cost for the facility.
  • Cost of fresh cutting fluid of $3/gal.
  • Typical activity usage rate of 3,000 gal./yr.
  • Capital Costs based on two 500-gallon tanks installed.
  • $950 minimum charge per visit for less than 1,000 gallons (O&M).
  • Six visits per year.

Table 1. Annual Cost Comparison for On-Site Recycling or Off-Site Recycling of Used Cutting Fluid


On-site Recycling

Off-site Recycling

Operational Costs:    
Service Cost: $5,700  
Fluid purchases: $4,500 $9,000
Total Operational Costs: $10,200 $9,000
Total Recovered Income: $0 $0
Net Annual Cost/Benefit: -$10,200 -$9,000

Economic Analysis Summary:

  • Annual Savings for On-site Recycling: -$1,200
  • Capital Cost for Diversion Equipment/Process: $3,000
  • Payback Period for Investment in Equipment/Process: N/A

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NSN/MSDS: None identified.

Approving Authority: Appropriate authority for making process changes should always be sought and obtained prior to procuring or implementing any of the technologies identified herein.

Points of Contact: For more information

Vendors: This is not meant to be a complete list, as there are other manufacturers of this type of equipment.

102 Lincoln Street
Verona, WI   53593
Phone: (608) 845-6771 or (800) 356-9042
FAX: (608) 845-6792
URL: http://www.cecor.net/

Waterlink Inc.
1350 Euclid Ave. 10th Fl.
Cleveland, OH 44115
Phone: (216) 861-9195
FAX: (216) 861-9849
URL: http://www.waterlink.com/

Master Chemical Corporation
501 West Boundary
Perrysburg, OH 43551-1263
Phone: (419) 874-7902
FAX: (419) 874-0684
URL: http://www.masterchemical.com/

Related Links: None

Sources: Mr. Cliff Myers, Defense Supply Center Richmond, March 1999.