Archive for the ‘MWF Microbiology’ Category


Thirteen years after Metalworking Fluids, 2nd Ed. was published, the third edition is now available. Metalworking Fluids, 3rd Ed. Jerry Byers, Ed. has just been published (ISBN, Hardbound: 978-1-4987-2222-3; E-book: 978-1-14987-2223-0) and is available from STLE, CRC Press, or Taylor & Francis.

MWF 3rd. Ed. promises to become the new MWF bible. All of its chapters reflect either substantial updates or all new material. I recommend this new volume most strongly to all metalworking industry stakeholders.

Full disclosure, I wrote Chapter 11 – Microbiology of Metalworking Fluids. Many of the other chapters were written by colleagues on STLE’s Metalworking Fluid Education and Training Subcommittee.


ASTM E2694, Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids, was first approved in 2009. The 2016 revision of the method has just been published by ASTM ( This version includes a new Appendix X4 that provides a protocol for differentiating between bacterial and fungal contamination in metalworking fluids. I had first written about this protocol here in my 04 May 2015 blog. The original research on which the ASTM E2694 revision was based was published in 2014: Passman, F.J. and Küenzi, P., “A Differential Adenosine Triphosphate Test Method for Differentiating between Bacterial and Fungal Contamination in Water-Miscible Metalworking Fluids” International Biodeterioration & Biodegradation (2014), 0964-8305.
Appendix X4 is meant to be used only on samples that have high cATP concentrations as determined by the basic E2694 test. I generally consider ≥1,000 pg/mL to be high cATP, but others might choose to be more conservative. The differential method guides microbicide selection. If the ATP-biomass is all from bacteria, then a tankside addition of bactericide is generally the appropriate treatment. If it is from fungi, then a fungicide will be needed. A broad-spectrum microbicide or compatible bactericide and fungicide are needed to control an infection that is due to a combination of bacteria and fungi. For more information, contact me at 609.716.0200 or


How many of you recall the Bob Seeger song: Where have all the flowers gone? It seems that it might be time to modify the lyrics by replacing the word flowers with biocides approved for use in metalworking fluids (MWF). I admit, that’s a mouthful, but the reality is comparable to that behind the original song. The list of active substances for which Biocidal Products Regulation (BPR) dossiers have been submitted includes a mere 27 actives intended for use in MWF. Less than 10 years ago, there were more than 100 options. The dust hasn’t yet settled in the USA, but once the US EPA’s Office of Pesticides Programs rules on the maximum permissible dosage of triazine in MWF later this year, it’s likely that the ASTM E2169, Table 2 list of active ingredients approved for use in MWF will be a fraction of its original length. Perhaps, when compared with our European friends, we are still lucky in the USA. A literal reading of the BPR’s definition of a Biocidal Product suggests that all MWF are Biocidal Products. The UEIL is advocating that MWF be formally recognized as Treated Products (the cost impact is an estimated $250,000 U.S. per MWF formulation – not trivial). Regulators have promised to give UEIL’s arguments full consideration, but nothing has yet been put in writing. I reviewed the latest state of affairs in my January 2016 TAE presentation. Please contact me if you are interested in receiving a copy of the manuscript: Impact of Biocidal Product Regulation on Microbial Contamination Control in Metalworking Fluids.

Using ATP to evaluate biofilm dispersants.

If you will be attending the STLE Annual Meeting on 15 through 19 May 2016, be sure to join me at the Metalworking Fluids Technical Session III, in the Silver Room, Bally’s Las Vegas, NV. At 0830h, on Tuesday 17 May, I’ll be presenting my paper: “Adenosine Triphosphate Testing to Evaluate Biofilm Dispersants.” The paper discusses the use of LuminUltra Technologies Limited’s QGO-M and DSA test methods to compare the efficacy of a number of different formulations for removing biofilm from pipe surfaces without being biocidal. As regulators increasingly restrict the use of MWF microbicides, it is becoming increasingly important to develop non-biocidal biodeterioration prevention strategies. My STLE presentation will speak directly to this issue. I’m looking forward to seeing you in Las Vegas. Please contact me directly (see “REQUEST INFORMATION” on BCA’s home page) if you would like to schedule a conversation during the STLE Annual Meeting.

The Truth is Out There…

For those of you who are interested in metalworking fluid microbiology and microbial contamination control, I invite you to read my March 2016 Tribology and Lubrication Transactions TLT) article: MWF Biocides Part II – Science vs. Fiction.
This was an accidental article that I was asked to write in response to an error-laden article that had appeared in TLT’s November issue. The earlier piece had been written by an individual whose familiarity with the topic was limited to the research performed in the process of drafting the TLT submission. I had not yet read the article when I started receiving flaming emails from industry colleagues who mistakenly believed that I had an editorial role and had somehow approved the article for publication. Initially, my plan was to write a letter to the editor. Indeed, I wrote a draft letter listing each error and the correct information (with relevant references cited as appropriate). The letter morphed into the March article. To be sure that I wasn’t just offering my personal opinions, I recruited log time colleagues Drs. Neil Canter and Alan Eachus and Mssrs. Jerry Byers and Richard Rotherham to co-author the article. I am much indebted to each of them for their contributions to the effort.
MWF Biocides Part II focuses primarily on the scientifically unsupportable conflation of formaldehyde (HCHO) and formaldehyde-condensate microbicides (FCM). The toxicological profiles of FCM differ among specific chemistries, but as a group are substantially different from HCHO. Moreover, although regulators assume that 100% of the HCHO in FCM will end up in the air above metalworking fluids (MWF) threated with FCM, data prove otherwise. Over the past couple of years, the number of microbicides approved for use in MWF has plummeted. In Europe there are only 27 listed biocidal substances (most are still going through regulatory review) that can be used in MWF. In the U.S., by last summer, the US EPA’s Office of Pesticides Programs will most likely issue guidance that will determine the future availability of FCM. In addition to clarifying the FCM issues that had been misreported in the November article, the March article sets the record straight on nearly 30 other misstatements made in the earlier publication.
Please contact me at for a copy of the MWF Biocides Part II.

Legionella pneumophila in Metalworking Fluids

I’m sharing an email exchange that I had with a colleague who had asked about the risk of L. pneumophila (the microbe that causes Legionnaire’s disease) in MWF.
Thank you for posting your query to BCA’s website.

You wrote:
“I wondered if you could help me answer a customer’s question. One of my customer’s machine tool operators is in the hospital being treated for Legionnaires’ disease. My customer asked me if the Kathon 886 MW or Kathon CC kills this strain of bacteria. I really appreciate your help and advice. I attend the annual STLE meeting every year and hear you speak on maintaining and monitoring metal working fluids, so I thought you would be the best source to ask. The Legionnaires’ disease was most likely contracted in Tennessee while this gentleman was on vacation. Other machine operators are now afraid they might contract the disease through the metal working fluids in the plant.
Thank you for your time and thoughts.”

The short answer is yes.

Not long after Legionella pneumophila was identified as the disease agent that caused Legionnaire’s disease, Rohm & Haas tested Kathon WT1.5 efficacy against the bacterium. WT1.5 is just Dow’s (formerly R & H) water treatment market label for the 1.5% active product we use as Kathon 886MW and 886MW 1.5 in the MW industry.

Keep in mind that L. pneumophila is ubiquitous. If you recall the incident at Ford’s Le Brea, OH plant some years ago, four machinists came down with Legionnaire’s disease. Attempts to detect L. pneumophila from MWF systems all failed. An immunological survey of all of the plant’s employees revealed that the majority has antibodies to L. pneumophila. Other immunological surveys (populations outside our industry) have demonstrated that the majority of the population has been exposed to the microbe (i.e.: has the antibodies). Most of the time, folks who contract the disease have other health problems that render them more susceptible than the general population. Back to Le Brea. That incident and a cluster of Pontiac Fever cases at a Pontiac Plant in Windsor Ontario in 1981 are the only two clusters of Legionnaire’s disease that have been reported in the MW industry. The 1981 outbreak was caused by L. feeleii growing in the facility’s cooling towers. The source of L. pneumophila at Le Brea was never confirmed.

From what we know, workers are much more likely to be at risk from improperly controlled heat exchange systems/cooling towers than from MWF.

What’s New – June 2014

In January 2014, at TAE’s 19th Tribology Colloquium, I presented th preliminary results of field evaluations that were being performed on LuminUltra Technologies dQGO-M test method. The new ATP test method provides a simple and reliable means of differentiating between fungal and bacterial contamination in metalworking fluids (MWF).

Four international MWF compounders participated in the field evaluation. All of their data were subitted in time for my STLE 2014 Annual Meeting Presentation:

Recent advances in the differentiation between fungal and bacterial contamination in metalworking fluids using modifications of the ASTM E2694 Standard Test Method. Read more…

What’s New – November 2013

On March 11 through 14, 2014, Dr. Neil Canter, Mr. John Burke and I will once again be presenting STLE’s Metalworking Fluid Certificate Training Course. The course will be held in Atlanta, GA. For more information, visit the STLE website…

In January, 2013, at TAE’s 9th Fuels Colloquim, I presented a paper describing modifications of ASTM Mehtod D7687 (ATP in Fuel) that permitted detection of dormant microbes possibly present in fuel samples, and differentiation between bacterial and fungal biomass in fuel and MWF samples. In October, 2013, at the 13th International Symposium on the Stability and Handling of Liquid Fuels, I presented an updated version of the TAE paper.

In June 2013, I was honored to be presented with ASTM’s Award of Merit.

What’s New – January 2013

It’s been a busy couple of months since the November update. This month’s What’s New includes several course announcements, links to four webinars and announcements about two new ASTM Standards.

On February 19 thorugh 21, Dr. Neil Canter and I will be presenting STLE’s Metalworking Fluid Certificate Training Course in Philadelphia PA. For more information see the STLE flier…

Also coming up in March, I’ll be teaching two, one-day courses at Fuels & Lubes Asia 2013 ( On Tuesday, 12 March I’ll be presenting Metalworking Fluid Health and Safety (read more…) and on Wednesday 13 March I’ll be presenting Fuel Microbiology (read more…). Both of these courses present new material and focus on the economic impacts of the issues covered, along with explanations of those issues geared towards folks with backgrounds ranging from non-technical to purely technical. I invite you to join me in Bangkok for Fuels and Lubes Asia 2013.

I’ve now added hyperlinks to four webinars to the BCA website. Two webinars address fuel microbiology issues. And two address metalworking fluid microbiol.

  • The Importance of Biological Monitoring in Liquid Fuel Handling and Biological Monitoring of Metalworking Fluids can be found on LuminUltra Technologies’ webinar archive site. In the Importance of Biological Monitoring in Liquid Fuel Handling I discuss some of the basics about microbial contamination – focusing in on they various types of damage that microbes can cause to petroleum systems.
  • Similarly, Biological Monitoring of Metalworking Fluids offers an overview of metalworking fluid management and the role of effective microbial contamination control in best practice fluid management.
  • The third webinar discusses the economic impact (value proposition) of real-time microbial contamination in retail fuel systems. Did you know that at retail sites in urban areas, where vehicles line up waiting for their turn at the dispenser, flow rate restrictions as little as 10% can cost retailers >$100,000 US per dispenser per year? Find out how microbial condition monitoring can contribute directly to fuel retail profitability.
  • The fourth webinar in this series reviews the economic benefits (again, value proposition) of real-time microbial contamination condition monitoring. If you provide metalworking fluid management services or operate metalworking facilities, this is a must see webinar.

ASTM E2889 Practice for Control of Respiratory Hazards in the Metal Removal Fluid Environment is the first ASTM Standard to list recommended exposure limits for hazardous components of metalworking fluid aerosols. Just as significantly, the Practice provides guidelines for minimizing exposure risks. Read more…

ASTM D2881 Classification for Metal Working Fluids and Related Materials has been overhauled with the addition or revision of nine classifications and definitions. Read more…

ASTM D7847 Guide for Interlaboratory Studies for Microbiological Test Methods is the first ASTM Standard to grapple with the particular challenges presented when designing and performing interlaboratory studies (ILS) to detemine the precision of fuel microbiology test methods. Read more…

What’s New – November 2012

LinkedIn MWF Interest Group Microbiocide discussion that ran from August through September 2012. A question about microcbiocide selection for semisynthetic MWF triggered a lively discussion that included more than 50 posts. Although some of the posts contained useful information, a substantial number were based on limited experience and unsupportable personal impressions. I’ve compiled my contributions to the LinkedIn discussion and had a number of MWF industry experts review them for relevance and accuracy before posting them here. Read my compiled comments…

2001 L.U.S.T.Line article on microbiologically influenced corrosion in fuel system underground storage tanks removed from BCA’s website. In October 2012, I received a letter from the Fiberglass Tank & Pipeline Institute’s (FTPI) attorney, demanding that I remove this article. In the article I had speculated about the likely mechanism and appearance of fiber reinforced polymer (FRP) tank failure if such failure was due to biodeterioration. My hypothesis was based on FRP failure mechanisms that had been reported in the scientific literature (see bibliography). However, as a measure of good will, I have removed the offending article form this website and have replaced it with a PDF of my exchange with FPTI’s attorney. Read more…

Correction – The version of Non-conventional Methods for Estimating Bioburdens in Fuel Systems Rapidly that has been available on the website was missing the Discussion & Conclusion sections. The incomplete paper has now been replaced with a complete version. Read the full paper…


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