SEMI-SYNTHETIC AND SYNTHETIC COOLANT SUBSTITUTION

Revision Date: 11/01
Process Code: Navy/Marines: ID-10-00; Air Force: RR-01; Army: MTF
Usage: Navy: Medium; Marines: Medium;
Army: Medium; Air Force: Medium
Compliance Impact: Low
Alternative for: Conventional Cutting Fluids
Applicable EPCRA Targeted Constituents: Dichloromethane (CAS: 75-09-2), 1,1,1-trichloroethane (CAS: 71-55-6), Trichlorofluoromethane (CAS: 75-69-4), Xylene (CAS: 1330-20-7), Acetone (CAS: 67-64-1), Spent Halogenated And Non-halogentated Solvents

Overview: Semi-synthetic and synthetic coolants typically have longer useful lives, and thus require fewer changeouts than conventional oil-based cutting fluids. Semi-synthetic and synthetic coolants are also more resistant to problems such as rapid bacterial growth, which is often the reason coolants are disposed of prematurely. At a typical shop, the personnel change cooling fluid when it emits a rancid odor. The odor is caused by anaerobic bacterial growth and does not indicate that the cutting fluid has lost its cooling and lubricating properties. However, the presence of these microorganisms over a period of time can cause coolants to degrade. The resulting adverse condition of the coolant include foul odors, clogged transfer lines, changes in pH, and splitting emulsions. These conditions can affect the quality of the final product.

The coolant is typically removed from the cutting machine's sumps when the odor of the bacterial growth bothers shop personnel. On average, the coolant is removed from the cutting machines every 3 weeks. The time between fluid change is usually 2 to 3 weeks in the summer months, while it is extended to 3 to 4 weeks during the winter. This is due to the variance of temperature and moisture, both of which affect the rate of bacterial growth.

Several DOD facilities have switched to a semi-synthetic coolant with considerable success. Personnel at Portsmouth Naval Shipyard in New Hampshire, Code 120, have tested semi-synthetic coolants including Castrol TLS-995 and Blaser SwissLube 400. This effort was conducted as part of a NAVSEA machine shop modernization program to determine cutting fluid pollution prevention alternatives among eight naval shipyards. The results showed that the semi-synthetic coolant had been in use for over 6 months without changeout or experiencing the bacterial growth problems encountered at other facilities which use oil-based coolants. By switching to a semi-synthetic coolant that would last 6 months, an activity can reduce the amount of coolant waste by almost 90%, as evidenced at NADEP Norfolk.

Both synthetic and conventional oil-based coolants may be characterized as hazardous due to the productís formulation. Waste reduction is achieved as a result of longer service life of synthetic coolants compared to oil-based coolants. Either formulation may be a characteristic hazardous waste. 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, and has become contaminated through use. Coolants may be managed under these regulatory provision and recycled as opposed to disposed.


Compliance Benefit: A facility will use less semi-synthetic and synthetic coolants than a traditional coolant since they do not need to be changed out as often. Since less coolant should be stored on site, a facility may decrease the possibility they will meet any reporting thresholds for those chemical under 40 CFR 355 and EO 12856.

The compliance benefits listed here are only meant to be used as a general guideline 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 were identified.


Safety and Health: There are mild dermal and eye irritation effects 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.


Benefits:
  • Reduce coolant waste by as much as 90%.
  • Lower disposal costs.
  • Reduce coolant replacement costs.


Disadvantages:
  • Semi-synthetic and synthetic coolants cost more than oil-based coolants.


Economic Analysis: The extra expenditure in purchasing semi-synthetic and synthetic coolants is offset by the savings incurred from by the reduced frequency of coolant replacement. For this economic analysis, the synthetic cutting fluid prices were provided by DLA and the oil-based cutting fluid prices were obtained through vendors. The labor time for replacement of cutting fluids and recycling data were based on estimates provided by the Portsmouth Naval Shipyard

Assumptions:

  • Spent cutting fluid generation rate for oil-based: 2 gal./hr., 4,212 gal./yr.
  • Labor to replace machine cutting oils is estimated at approximately 2 hours per week
  • Both oil-based and synthetic cutting fluids are recycled at no cost to the facility
  • Cost of fresh oil-based cutting fluid: $5.60/gal.
  • Cost of synthetic cutting fluid: $16.41/gallon based on a purchase of a 55 gallon drum
  • Use of synthetic reduces amount of coolant waste generated by 85 percent, reduces labor for changing fluid by 85 percent
  • Labor cost: $30/hr.

Annual Operating Cost Comparison of Synthetic and Oil-based Cutting Fluids

 

Synthetic

Oil-based

Operational Costs:    
Labor: $468 $3,120
Fluid purchases: $10,367 $23,587
Total Operational Costs: $10,835 $26,707
Total Recovered Income: $0 $0
Net Annual Cost/Benefit: $-10,835 $-26,707

Economic Analysis Summary

    Annual Savings for Synthetic: $15,872
    Capital Cost for Diversion Equipment/Process: $0
    Payback Period for Investment in Equipment/Process: Immediate

Click Here to view an Active Spreadsheet for this Economic Analysis and Enter Your Own Values. To return from the Active Spreadsheet, click the reverse arrow in the Tool Bar.


ApprovingAuthority: Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.


NSN/MSDS:
Product NSN Unit Size Cost MSDS*
Dascool 2003 Cutting Fluid 6850-01-387-4484 55 gal. Drum $902.75 Click me

*There are multiple MSDSs for most NSNs.
The MSDS (if shown above) is only meant to serve as an example.


Points of Contact: Navy:
Mr. Richard Collette
Shop 31, Bldg.300
Portsmouth Naval Shipyard
Portsmouth, NH 03804-5000
Phone: (207) 438-5330
Fax: (207) 438-5321
Email: lightbodyb@psns.navy.mil


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

Castrol Industrial East Inc.
775 Louis Dr.
Warminster,  PA   18974
Phone: (215) 443-5220 or (800) 464-3070
Fax: (215) 443-7094
URL: http://www.castrolindustrialna.com/

Milacron Manufacturing Technologies
2090 Florence Ave.
P.O. Box 63716
Cincinnati, OH 45206-2425
Phone: (513) 487-5000
Fax: (513) 487-5057
URL: http://www.milacron.com/

Spartan Chemical Co., Inc.
1110 Spartan Drive
Maumee, OH 43537-0110
Phone: (800) 537-8990 or (419) 531-5551
Fax: (419) 536-8423
URL: http://www.spartanchemical.com/

D. A. Stuart Inc.
43 Upton Road
Scarborough, Ontario,  M1L2C1
CANADA
Phone: (416) 757-3226 
FAX: (416) 757-3220
URL: http://www.dastuart.com/

 

Sources: None listed



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