JOHN HANLEY, Employee/Respondent, v. CRETEX CO., INC., and AM. INS. CO., with claims administered by BROADSPIRE, Employer-Insurer/Appellants, and MEDICA HEALTH PLANS and GRP. HEALTH PLAN d/b/a HEALTH PARTNERS, INC., Intervenors.

MAY 10, 2021
No. WC20-6389

OCCUPATIONAL DISEASE - ASTHMA; CAUSATION - SUBSTANTIAL EVIDENCE.  Substantial evidence, including expert opinion, supported the compensation judge’s conclusion that the employee developed occupational asthma due to exposure to aerosolized oils in the workplace.

    Determined by:
  1. Sean M. Quinn, Judge
  2. David A. Stofferahn, Judge
  3. Gary M. Hall, Judge

Compensation Judge: William J. Marshall

Attorneys: Vincent Peterson, Law Office of Donald J. Noack, Jr., Mound, Minnesota, for the Respondent. Luke Smith, Brown & Carlson, P.A., Minneapolis, Minnesota, for the Appellants.




The employer and insurer appeal the Findings and Order of a compensation judge granting the employee’s claims for workers’ compensation benefits.  We affirm.


In 2006, the employee, John Hanley, completed his machining technology degree and was hired by the employer, Cretex, as a CNC lathe operator.  A CNC lathe is used in the manufacturing process of orthopedic implant devices.  The employer operated a large machine shop that was described by the employee as the size of a large Walmart store.  When the employee started, there were approximately 500 machines, including lathes, each approximately the size of a minivan, in the building and close to 1,000 machines when he stopped working for the employer.  The employee testified that there was about three to six feet of space between the machines, with the amount of space shrinking as more machines were added to the building.  Likewise, there were approximately 500 employees when the employee started working for the employer, and approximately 800 employees at the end of his employment.  Machinists like the employee stood near a given machine, using a control panel to operate it, while watching the manufacturing process. Often the employee would run multiple lathes at a time.

The lathes cut metal, typically stainless steel or titanium, into parts, by turning as fast as 10,000 revolutions per minute (RPMs).  This speed results in friction between the cutting tool and the metal.  This friction is mitigated by high pressure lightweight oil, which is applied to the part as it spins in the lathe.  In the process, the oil is aerosolized into a fine mist.  As aerosolized oil is volatile, the lathes are vented by powerful fans above the work area, drawing the air upwards.  Despite the venting, residual aerosolized oil escapes into the vicinity of the lathe when the machinist opens the door to insert or remove the metal.  The employee testified that he would open and close a lathe door as few as five times and as many as 100 times in a given workday.  Moreover, the doors to the lathe were not airtight and despite the ventilation system, some aerosolized oil would escape during the cutting process.

Some days the employee would go home coated in oil, noticing it on his clothes and skin.  He testified that he could smell the oil on his clothes and feel it on his skin, saying, “It's very apparent that you're being exposed to this stuff.”  (T. 57.)

The employer’s director of safety performed air quality testing pursuant to federal regulations and protocols at the machine shop on at least five occasions from 2012 through 2018.  After each test, he completed Industrial Hygiene Evaluation Reports, based on the data from the testing.  The reports showed that the air quality in the shops where the employee worked had aerosolized oil about 30 times below the permissible amount according to federal regulations.  (Exs. 10-13 and 15.)

In 2009, the employee began to experience respiratory symptoms.  These symptoms included chest tightness, trouble sleeping, and difficulty breathing.  The more he worked, the worse his symptoms became.  Starting in October 2012, he switched to a three-day weekend schedule, working 12-hour shifts, Friday through Sunday.  He made the switch to this shift so that he could have four consecutive off days.  He noticed his symptoms improved after four off days but worsened by the third straight workday.

The employee became more sensitive as more exposure occurred, experiencing problems with things that had been uneventful before.  He is now sensitive to swimming pool fumes from chlorine gas, paint fumes, dust from sweeping out his garage, and campfires.  Of these exposures, metalworking oils aggravate his symptoms more than any other irritant.

The employee treated at Allina Clinic for his respiratory symptoms from February 2017 through May 2018.  Dr. Naeem Adhami ordered a methacholine challenge test done on February 15, 2017, at Mercy Hospital.  The test showed the employee likely suffered from asthma, although appropriate clinical correlation was needed.  Dr. Adhami concluded that the employee’s symptoms and tests were consistent with severe reactive airway disease due to exposure at work for over 10 years.  He diagnosed occupational asthma.  Dr. Adhami suggested that given the employee’s symptoms improved when he was not at work, he should try different employment.  The employee switched to a different department with the employer but was still working near oil-mist producing machines.  He left the employer in March 2017.

After leaving his job, the employee noticed that his symptoms improved almost immediately, with his chest tightness gone, and no more breathing issues.  He thought he was able to return to machine work and started with a different employer, LISI, in October 2017.  LISI was a smaller shop with more space between the machines.  He had oil on his skin and clothes after shifts at LISI, but less than that from his work with the employer.  Eventually, however, his symptoms returned, and he left LISI after 12 months.  Again, his symptoms improved after leaving the work environment.

After not working for a period of time and experiencing improvement in his symptoms, the employee returned to work with the employer in 2019.  The new job was at a different shop with only about 70 machines and more space between the machines.  He saw Dr. Zeke McKinney at HealthPartners for a return-to-work physical examination on March 19, 2019. Dr. McKinney noted that the employer’s work environment was “an extremely clean environment” and that the employee might do well returning to work with the employer.  (Ex. F.)  Dr. McKinney approved the employee for the new job but required that he wear a P-100 respirator.

Because Dr. McKinney ordered the use of a respirator mask, the employer sent the employee to see Dr. Orrin Mann, with Minnesota Occupational Health, to get clearance for the mask use.  During this May 8, 2019, visit, the employee brought his peak flow tracking meter results to show Dr. Mann.  These results showed better airway breathing before work and worse after work. The employee also brought the methacholine challenge test results.  The employee described worsening symptoms during the day, even when using a respirator, when exposed to metalworking aerosols.  The employee described symptoms of cough, wheezing, chest tightness, chest pain, prolonged shortness of breath, and extreme fatigue, among other things.  He noted that tiny amounts of exposure provoked his symptoms.  Dr. Mann diagnosed occupational asthma triggered by metalworking fluids and concluded that a respirator mask was insufficient to treat the employee’s symptoms.  Dr. Mann concluded that the only option was to keep the employee away from metalworking fluids.  As he was sensitized, however rare, because of these exposures, Dr. Mann permanently removed the employee from the work environment.

The employee continued to treat with Dr. McKinney several times from May through July 2019, with improvement of symptoms when off work for consecutive days.  By July 8, 2019, Dr. McKinney noted that it might be reasonable for the employee to return to metalworking where water-based fluids were used, not oil-based fluids.  Dr. McKinney also noted that the employee had work-related occupational asthma which was probably from his work with the employer culminating from his earlier exposures through 2017.  He restricted the employee from being within 6 feet of where oil-based metalworking fluids are aerosolized.

The combination of the restrictions from Dr. Mann and Dr. McKinney essentially precluded the employee from working for the employer.

The employee took a different job with a different employer in July 2019 but was still exposed to some chemicals although they were non-oil-based chemicals.  After a few months, he had a recurrence of his symptoms and left that employment in November 2019.  He decided to get his commercial driver’s license, starting school in March 2020, and completing it in August 2020.  He is optimistic about his future as a commercial truck driver because car driving does not cause symptoms and he did not have any symptoms during truck driving training.  He was hired as a commercial driver in September 2020.  He had no exposure to cutting oils from December 2019 and has exhibited minimal respiratory symptoms.

The employee was seen by Dr. John Kipp at the request of the employer and insurer.  Dr. Kipp issued his report dated October 10, 2019.  He also issued supplemental reports on November 18, 2019, and September 4, 2020.  He concluded that the employee did not suffer from occupational asthma and might not even suffer from asthma at all.  He suspected the employee had a respiratory obstruction due to an extrathoracic cause, most likely a vocal cord dysfunction.  He concluded that the employee could not have occupational asthma because the work environment was very clean, and the oil exposures were far below OSHA standards and that the probability of any irritants inducing asthma was very low.  (Exs. 1, 4, and 6.)

The employee was seen by Dr. Patrick Arndt at the request of his own attorney.  Dr. Arndt completed a report dated May 13, 2020.  (Ex. I.)  He described the employee as suffering from occupational asthma likely due to exposure to metalworking fluids, a known cause of occupational asthma.  He disagreed with Dr. Kipp’s diagnosis of vocal cord dysfunction.  Dr. Arndt concluded that the occupational asthma diagnosis was further confirmed due to the employee’s consistent improvement when away from fluids and the return of symptoms upon going back to work.  He also concluded that the employee now had become sensitized to other exposures and thus was having reactions to campfire smokes, gas fumes, and other irritants.  He advised against any type of metalworking fluid exposure and to avoid smoke, dust, fumes, and other irritants.

This matter came on for trial before a compensation judge on September 9, 2020.  Dr. Arndt’s reports were admitted over the employer and insurer’s foundational objections.  (T. 10.)  On October 27, 2020, the compensation judge issued his Findings and Order, granting the employee’s claims.  The compensation judge found that the employee developed permanent and ongoing occupational asthma through exposure to metalworking fluids with the employer.  (Finding 33.)  The employer and insurer appeal.


On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1(3).  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

A decision which rests upon the application of a statute or rule to essentially undisputed facts generally involves a question of law which the Workers’ Compensation Court of Appeals may consider de novo.  Krovchuk v. Koch Oil Refinery, 48 W.C.D. 607, 608 (W.C.C.A. 1993), summarily aff’d (Minn. June 3, 1993).


The employer and insurer assert that substantial evidence does not support the compensation judge’s finding that the employee suffered occupational asthma due to exposure to aerosolized oils.  We are not persuaded by the employer and insurer's arguments.

At hearing, the employer and insurer argued that because the industrial hygiene testing showed the air quality fell far below the maximum aerosolized oil exposure allowed under OSHA guidelines, the employee could not have developed occupational asthma.  The compensation judge rejected this argument, noting that the Workers’ Compensation Act is not a negligence-based statute and that meeting governmental safety standards did not preclude the employee from developing occupational asthma.

The employer and insurer state that they are not arguing that compliance with the guidelines shields them from liability as a matter of law, but rather that there is only one medical opinion based on objective foundation.  First, they state that Dr. Kipp opined that the employee did not suffer from occupational asthma based upon the objective data regarding the air quality at the work site.  Second, they state that Dr. Arndt’s opinion that the employee had asthma due to high exposures to aerosolized oils was contrary to the objective industrial hygiene reports.  As such, they argue, that because Dr. Arndt’s opinion is based on objectively false information and the assumption that the work environment was unsafe, the opinion lacked foundation.  (Employer and Insurer’s Brief, at 21.)  They further argue that the compensation judge conceded that they had a clean work environment because he found, in Finding 4, that only “some” aerosolized oil escaped into the air.  If the environment was clean such that only “some” aerosolized oil escaped into the air, then this would be contrary to what Dr. Arndt assumed.  This would make a finding of a clean environment inconsistent with accepting Dr. Arndt’s opinion as persuasive.  We are not persuaded by these arguments.

First, in Finding 4, the compensation judge found that despite the ventilation systems in use, “some of the aerosolized oils would escape into the air.  The employee would be exposed to the oils via breathing as well as a coating on the employee’s clothes by the end of his shift.”  (Finding 4.)  While the compensation judge acknowledged that the employer did a commendable job with their ventilation systems, the employee was exposed such that his clothes and skin were covered with oil at the end of a work shift.  The word “some” does not mean, as argued by the employer and insurer, that the amount of oil was essentially non-existent to the point of being objectively incapable of causing occupational asthma.

Second, while Dr. Arndt expressed a lack of understanding of the industrial hygiene reports, his opinion is consistent with the employee’s testimony that he would come home from work coated in oil.  This testimony was found credible by the compensation judge.  Moreover, Dr. Arndt’s opinion is consistent with that of Dr. McKinney, who stated clearly that he was aware of the relatively clean nature of the employer’s workplace, but nevertheless concluded that the employee had work-related occupational asthma.  Dr. Arndt’s opinion was also consistent with that of Dr. Mann who, after an evaluation of the employee at the request of the employer, reached the same diagnosis and causation opinion.  Dr. Arndt’s opinion is consistent with the employee’s description of symptoms as worse at the end of a workday and a three-day shift, and better after being away from the work environment.

Third, Dr. Kipp opined that as the employer’s air quality is well within OSHA and similar standards, the employee did not develop occupational asthma from working there.  While the employer and insurer may claim that they are not making a negligence-based argument, they are doing just that.  There is no doubt that the industrial hygiene reports show, on at least five separate occasions, that the quality of the air measured was such that aerosolized oils were well below OSHA standards for maximum permissible exposure.  That does not mean, however, that the employee’s testimony cannot be believed.[1]  As every person is unique, exposure to even minimal amounts of aerosolized oils may cause occupational asthma.[2]  While the chances of any given employee developing such a disease may be substantially less due to the employer’s excellent ventilation system, the chances are not zero for every employee.

Fourth, the air quality tests did not measure the employee’s specific exposure.  Tests were done on at least five separate dates somewhere within the large machine shop.  The employee worked for the employer for approximately 10 years in a building large enough to hold up to 1,000 machines, each the size of a minivan.  The safety director testified that the tests were done at the level of where an employee’s head would typically be and that each machine is essentially the same.  While that may be generally true, the air quality in one location of the building was not necessarily equal throughout, particularly over a 10-year time frame.  This is a question of fact properly resolved by the compensation judge based on the hearing record.

Substantial evidence supports the compensation judge’s findings that the employee developed occupational asthma.  For that reason, we affirm the Findings and Order of the compensation judge. 

[1] The compensation judge found the employee credibly described his clothes being covered with oil mist, his skin being slick with oil, and having an oil odor about him at the end of his workdays.  He further testified regarding asthmatic symptoms coming on particularly at the end of a workday and at the end of a three-day work shift, his symptoms improving after four days of not working, and during extended periods of being away from aerosolized oil, an almost complete resolution of symptoms.

[2] Even Dr. Kipp acknowledged that there is still a possibility, albeit a low one, of a person developing occupation asthma from exposures to aerosolized oils that are within legal guidelines.  This undercuts the employer and insurer’s argument that such an outcome is not possible at all.