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Nickel Use in Hot Dip Galvanizing

May 30, 2012

Q. The NIOSH Pocket Guide to Chemical Hazards (2007) lists the maximum exposure limits for airborne nickel as: NIOSH TWA 0.015 mg/m3 and for OSHA TWA 1 mg/m3. For more than twenty years I wondered why the OSHA (a regulatory agency) limit was 67 times higher than the NIOSH limit. I just could not imagine a "company" with enough power to cause OSHA to set such a high exposure limit for airborne nickel. On May 28, 2012 I found the answer which is downloadable on the internet (Google) at:

Nickel Powder/Nuclear Weapons, The Untold Story Cliff Honicker

After reading this 26 page article, I would be happy to comment on any in-plant airborne nickel testing results that may be posted on this thread in Finishing.com.

Regards, Dr. Thomas H. Cook, Hot Springs, South Dakota, USA

Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

May 31, 2012

A. Hi, Dr. Cook. It is very difficult to see a consistent point in this story, and Cliff Honicker never says: "this is the point". Nonetheless, his central theme seems to be, not that OSHA-permitted levels of nickel are dangerous, but that the K-25 Oak Ridge workers were exposed to dangerous conditions that were deliberately covered up in order to not interfere with production, and that they were exposed to nickel carbonyl, microscopically fine inhaled nickel powders, UF6, and many other dangerous materials. He further seems to assert that the exposures were much much higher than the records indicate (i.e., dusts were allowed to settle for hours before measurement, so the records are not indicative of actual exposure levels).

I guess what I'm trying to say is that, in making his point about how dangerous the conditions were for the workers, and how those conditions were deliberately misrepresented, he seems to not have used anything from the records in a way to indicate that OSHA-permitted levels of nickel exposure are actually a problem. Yes, nickel exposure can be a problem, and it's possible that OSHA levels are not low enough, but I don't see how this article furthers that cause.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

June 1, 2012

A. Ted,

I agree the Honicker article has insufficient numbers and too many words. I also agree that the other poisons present confuse the issues. The article certainly presents some very useful information for hot dip galvanizers.

Two other article of interest are:

Nickel by Ernest Mastromatieo , M.D., D.P.H., D.I.H.
Am. Ind. Hyg. Assoc. J. 47(10):589-601 (1986)


An Evaluation of Airborne Nickel, Zinc, and Lead Exposure at Hot Dip Galvanizing Plants by Dave K. Verma and Don S. Shaw. AM. IND. HYG. ASSOC. J. 52(12):511-512(1991)

The first of these articles shows historically many, many cancers caused in nickel refining plants (wherever a dust is present). This article was recommended to me by the Nickel Development Association so as to show me how safe nickel is. It had the opposite effect.

The second of these articles gives airborne nickel numbers in actual galvanizing plants. This second article was financially supported by the nickel industry. My view is that there are problems in this article.

To obtain these two articles try inter-library loan or purchase off the internet.

Regards, Dr. Thomas H. Cook, Hot Springs, South Dakota, USA

Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

June 5, 2012

Q. Has anyone yet come up with an effective alternative to control "Sandelin" steels in galvanizing other than microalloying with Ni? If so what is it?

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK
crithwood logo

June 6, 2012

A. Geoff,

Yes. Me. NiftyGalv.


Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

June 8, 2012

A. Dr. Cook, you are an extraordinary contributor to this site, and a priceless help to the readers.

But the central idea here is that we can all share camaraderie and interesting technical discussions while our advertisers pay the bills. In return for their making the site possible, the rest of us work hard to avoid commerciality, and not try to steer business our own way, making the advertisers regret supporting the site :-(

Please, readers, if you see that a discussion is moving away from technical issues and towards proprietary commercial suggestions, try to steer away or this site won't be able to be here for you :-)


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

June 8, 2012


My primary reason for presenting information about nickel in hot dip galvanizing is a "heads up" for galvanizers to prevent future health problems in workers. I have also exposed my "hidden agenda" of having a competing process which does not use nickel or lead. To you I apologize for submitting an obvious advertisement and to your supporting advertisers I also apologize. As you know I financially supported finishing.com for one year, but it was not beneficial to my business. I do very much appreciate the opportunity to present what I have found in the literature and some experimental results:

From a state (in the USA) regulatory agency, five hot dip galvanizing workers (kettle skimming and ash "working") all had an exposure of about 0.013 milligrams/m3). This plant does not have a kettle enclosure, exhaust system. or bag house. The second row of the below table shows what percent above maximum exposure level 0.013 is:

In the first row of the table below are presented the current and proposed maximum airborne exposure limits for nickel (all in units mg/m3):

OSHA         NIOSH         NIOSH(A)        CALIFORNIA(B)
(2007)       (2007)        Proposed        Proposition 65
 1.0         0.015          0.005            0.001
 1.3%          87%           260%            1300%

(A)The 0.005 value NIOSH Proposed (1976) comes from page 2 of the Honicker article.

(B)The 0.001 value comes from an article on the internet as NICKEL AND COMPOUNDS-SCORECARD HOME "An acute Reference Exposure Level (REL) of 1 microgram per cubic meter is listed for nickel compounds in the Air Control Officers Association Air Toxics 'Hot Spots' Program..."

It is my understanding that OSHA is a regulatory agency and NIOSH is a conservative, scientific agency concerned with health aspects of workers. It is troubling that OSHA has 67 times higher limit on Nickel than does NIOSH.

In the Honicker article a lag in time of 20 to 35 years is mentioned from exposure to the onset of major health problems. Also mentioned is the use of urine nickel testing. The Honicker article lists sub acute, chronic symptoms of substantial nature.

Nickel chloride added to flux is currently being marketed in the USA. I recommend airborne nickel testing results be presented by the sellers of this product.


Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

June 12, 2012

A. Dr Cook is making some interesting and noteworthy comments. I would particularly like to comment on his statement about nickel refineries and cancers. It has been known for many years that workers in nickel refineries can suffer from excessively high occurrences of cancer; the most common cancers are lung, nasal sinuses and laryngeal. A lot of work has been done on the relative causes in relation to the types of nickel the workers are exposed to and it has been found that one of the most hazardous sources, in broad terms, is water soluble nickel.

However, when considering nickel refineries, water soluble nickel is a secondary interest because the airborne nickel is not in a soluble form. The important issue with refineries is the type of nickel ore being refined. It was established back in the 1920's or 1930's by, I believe, Gawkrodger (don't rely on this name, as I am not absolutely sure of it), in some work done in English and Welsh refineries. He showed that nickel subsulfides are particularly carcinogenic. This work has been replicated on numerous occasion since then and has confirmed these findings. The findings also strongly suggested that suboxides are also a high risk source, but subsequent work has not totally confirmed these findings. However, the bottom line is that when the refineries studied in the early work changed their nickel ore sources to non-subsulfides or suboxides, the incidences of cancer decreased.

One of the major problems with studies involving airborne pollution and cancers is the interference of smoking -- this is well known to cause cancers and can sometimes give false results in studies involving respiratory illnesses and diseases.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

June 15, 2012

A. Trevor,

I am well aware that nickel has caused many cancers in workers in the nickel refining industry. Perhaps 30 or more years ago nickel METAL was listed as a suspected or likely cancer causing agent in humans. In lab animals cancers were often induced using nickel powder. On page 224 of the 2007 Ed. USA NIOSH Pocket Guide to Chemical Hazards (CDC), Nickel is listed as: "TO: Nasal cavities, lungs, skin [lung and nasal cancer]." Thus it is clear that Metallic Nickel need not be soluble to cause cancer. On finishing.com letter number 58320, a steel worker laid her face down on a galvanized steel I-beam and had an allergenic reaction to the galvanizing. I believe that the galvanizer who galvanized that I-beam has 0.05% nickel and 1% lead in his zinc. He did not have a hexchrome quench.

The following methods may reduce Nickel (or Lead) worker exposure in hot dip galvanizing:

(1) Use dust masks (N95; with one rubber band) or personal respirators (two rubber bands and an aluminum nose clip) during periods of visible smoke or dust.

(2) Use a pipe to vent smoke/dust from an ash/skimmings recovery furnace to the outside of the building. This pipe (stack) will corrode though in a year or two due to high temperature and high chloride in the smoke, ash, dust.

(3) Wear a two rubber band personal respirator when transferring ash from the recovery barrel to the transport barrels.

(4) If the kettle has an enclosure, air extraction, and bag house, then be sure they are properly operating.

(5) Some galvanizers advocate rotating the workers (especially the ash/skimmings processing guy) so that one worker avoids excessive exposure. The problem here is that more workers would be exposed.

(6) Good hygiene can reduce worker Nickel (or Lead) exposure. Proper hand washing, not smoking cigarettes which have been soiled by dirty hands, keeping soiled clothing out of the lunch room, can all reduce Nickel (or Lead) exposure for workers.

(7) Grinding or sanding zinc icicles off the product or grinding or sanding before painting the galvanized product needs be properly done (likely with masks), and carefully cleaning up the floor dusts can reduce worker exposure to Nickel (and lead).

(8) If Nickel powder (or lead ingots) is stored, then put it in an isolated non-working area and keep the area around the powder or ingots vacuumed up.

(9) Do timely periodic worker urine/blood testing to determine the actual levels in the workers. Metals of interest include, but are not limited to: Nickel, Lead, Tin, Bismuth, Zinc, and any other metals that may be present.


Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

July 18, 2012

A. Cliff Honicker gave me the name of a woman that worked 1 1/2 years as an office person (1996) in the "nickel plant" during the enrichment of uranium for the U.S. government. She told me that her urine nickel test showed 26 times the maximum allowable nickel in her body. She was also exposed to 14 different kinds of toxic and radioactive materials for which she is receiving compensation from the U.S. government. Thus no conclusions can be made regarding the toxicity of nickel alone, however she thinks the sinus problems that she experiences are due to nickel. Since her exposure was only 16 years ago, the cancer possibility has likely not had time to show up. This entire thread is a "heads up" for galvanizers using nickel in their zinc bath.

Regards, Dr. Thomas H. Cook, Hot Springs, South Dakota, USA

Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

"Surely You're Joking Mr. Feynman"
from Abe Books

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March 6, 2013

Hi. For a bit of amusement, nobel prize winning physicist Richard Feynmann's "Surely You're Joking Mr. Feynmann" .
includes a chapter describing his safety visits to Oak Ridge during the Manhattan Project, when the Army was trying to keep the Oak Ridge personnel from killing themselves with radioactivity while also being careful to not let them have even the tiniest clue about what they were doing (after all, it was America's most closely guarded secret).


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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