# Public Comments to CPSC on NIST Technical Note
1781 : Modeling and Measuring the Effects of Portable
Gasoline Powered Generator Exhaust on Indoor Carbon
Monoxide Level , dated February 2013 (as of June 12, 2013)Secretary/Treasurer: THOMAS ASSOCIATES, INC.

1300 Sumner Ave. • Cleveland, Ohio 44115-2851 • 216-241-7333 • Fax 216-241-0105
URL: www.pgmaonline.com E-mail: pgma@pgmaonline.com June 7, 2013

Ms. Janet L. Buyer Project Manager Directorate for Engineering Sciences U.S. Consumer Product Safety Commission 4330 East West Highway Bethesda, MD 20814

SUBJECT: Comments to CPSC on NIST Technical Note 1781

Dear Ms. Buyer:

The Portable Generator Manufacturers’ Asso ciation (PGMA) is pleased to offer its comments on the recently released NIST Technical Note 1781.

PGMA is a trade association that seeks to develop and influence safety and performance standards for our industry’s products. As the history of both PGMA and the individual members of PGMA demonstrate, our commitment to safety is a sincere commitment, one backed by repeated actions and not simply empty words. Since our members include the major industry manufacturers of portable ge nerators sold in North America and a significant majority of the industry, we are th e recognized voice of the portable generator industry, particularly with respect to the para mount issue of the safety of our respective

customers.

Our member companies include:

• American Honda Motor Company

• Briggs & Stratton Power Products Group

• Champion Power Equipment

• Generac Power Systems

• Pramac America

• Subaru Industrial Power

• Techtronic Industries, North America

• Wacker Neuson Production Americas

• Yamaha Motor Corporation USAPGMA shares with CPSC the goal of promo ting and continuously improving the safe and proper use of portable generators. PGMA would note at the outset that, while the NIST
Technical Note 1781 is a valuable contribu tion to the many efforts already expended by PGMA, CPSC, and others aimed at achieving this shared goal, the NIST Technical Note does not draw any specific conclusions or ma ke any particular recommendations as to
actions that should be taken to achieve the ultimate safety goa l. It rather confirms by testing a point with which it would be hard fo r anyone to argue, that being that a device
that emits a lower amount of Carbon Monoxi de will result in a lower volume of Carbon Monoxide being present in the area in which th e emitting device is locat ed. In that sense, it is a bit difficult for PGMA to specifica lly respond to the NIST Technical Note. Nevertheless, PGMA offers the comments below in a spirit of cooperation and we look forward to working with you, NIST and others to make the use of our products even
safer.

It seems that a key premise of the NIST Technical Note is that reduced CO emission rates from common portable generators can provide additional critical time for consumers to recognize and escape, and thus reduce the number of CO deaths from portable generators. There is no documentation or study confirming th e validity of that premise. Given the importance of the premise to the Technical Note, PGMA encourages CPSC and/or NIST to provide the documentation or study on whic h the premise is based or to conduct a study to validate it. While the proposition may seem intuitive, it could also be possible that someone experiencing minor symptoms from reduced CO emissions will be even less likely to attribute them to CO than someone exposed to emissions from an unmodified generator. Moreover, decreas ing the rate of symptom onset would not benefit someone who is sleeping and could redu ce awareness that a serious problem is at
hand.

There are no warning signs commonly and uniquely associated with carbon monoxide poisoning regardless of how quickly the car bon monoxide poisoning occu rs or begins to
occur. This is because the headache and nausea which are associated with carbon monoxide poisoning are such common, everyday occurrences for virtually everyone that it is questionable whether those symptoms would be recognized as being caused by carbon monoxide exposure. Empirical data woul d be extremely valuable, and probably necessary, to support the propos ition that a consumer expe riencing early reactions to carbon monoxide poisoning would realize the source of the symptoms as carbon monoxide and react in the manner desired, that is to quickly remove himself or herself from the area to a place where there was fresh, untainted air.

An additional concern raised by the low CO technology is the potential for users to believe that portable generato rs are safe for indoor use an d whether the implementation of a low CO technology coul d result in users being more likely to use the product improperly. The potential for such additio nal misuse should be evaluated by CPSC.

We continue to support the statement in th e CPSC’s Press Release for the report on its study of low CO portable generators that r ecognizes that a carbon monoxide (CO) hazard
would continue to exist even if the technology applie d to the prototype generator that was the subject of the report and now the NIST T echnical Note, were applied to commercially available generators, and that educating owners about the pr oper use of their generators
needs to remain the first line of defense:“The CPSC continues to urge cons umers to never run their portable generators in their attached garages, in or even near their houses, including avoiding placement near windows or vents. Generators should only be used outside, far away from homes. CPSC cautions that even if portable gasoline powered generators were to incorporat e this technology, they would still need to be used outside, far from the ho me. The technology does not make them safe for indoor use.” (CPSC Press Release #12-278, September 14, 2012).

PGMA continues to encourage CPSC and/or NIST to conduct a study that includes a human factors analysis to determine the eff ectiveness of the existing CPSC mandated CO warning adopted in 2007. In any event, PGMA encourages CPSC to revise the mandated warning to incorporate the standards and format in ANSI Z535.3-2011 and Z535.4-2011.

THE NIST Technical Note further demonstrates that CO levels are affected by numerous variables creating a high degree of uncertainty as to how they interact , and an inability to
draw reliable conclusions from the dem onstration testing performed. The NIST Technical Note is further support for CPSC’s previous statement regarding the use of CO
alarms:

[CPSC] also recognizes th at “[a]nother important lin e of defense against CO poisoning is having CO alarms on each le vel of the home and outside sleeping areas. Based on available alarm data, 93 percent of CO-relate d deaths involving generators take place in homes with no CO alarms. Much like smoke alarms designed to alert consumers about smoke or fires, CO alarms are designed to alert consumers to dangerous CO levels and gi ve them time to get out of the house before becoming incapacitated.” (CPSC Press Release #12-278, September 14, 2012).

States and local communities throughout the Un ited States have rec ognized the role CO monitors play in protecting consumers from the multiple sources of CO present in everyday life – furnaces, space heaters, and charco al grills to name a fe w. As a result, the number of states adopting mandatory CO monitor laws and codes has increased significantly over the last 5 years. PGMA en courages the adoption of such a requirement in every state as a cost effective means of significantly reducing the CO hazard from multiple sources. CPSC and NIST could use their influence to further promote the adoption of statutes, regulations and building codes requiring the use of CO monitors in living spaces as a means of im plementing the objective of pr otecting users. PGMA also encourages CPSC or NIST to analyze the da ta collected on CO poisoning and deaths to develop a public awareness campaign that is targeted based on use conditions and user groups, similar to what has been done with ha zards such as fires and severe weather. PGMA would support such an effort by CPSC and/or NIST.

With respect to the Technical Note, if the elect ronic fuel injectors a nd closed loop air/fuel ratio control used in conjunction with cata lytic converters employed on the prototype generator were installed on currently availabl e generators, it would result in significant changes to the product that is on the market today. The Techni cal Note appears to simply repeat the statement from the CPSC Low CO Portable Generator Study concluding that the control technology is commer cially available without an evaluation of the changes to the product that would be necessary in or der to replace the product currently in the market place and perform comparably to it. As we and others have pointed outpreviously, the road from prototype to comm ercial viability is typically as long and fraught with as many issues as th e initial stages of development.

One of the most significant concerns rela ted to the incorporation of the employed technology is the effect of the increase in high combustion temperatures which are detrimental to air-cooled engine durability a nd performance. In addition, the durability impact varies significantly on engines of diff erent sizes, designs, applications, and rated speeds thus making it difficult, if not impossi ble for the results from a single product to be generally applicable to the entire categor y of portable generators. The breadth of product in the portable generator category and the scalability of the employed technology in terms of cost, performance and efficiency will vary significantly between 50 cc and 500 cc sized engines.

Any conclusions regard ing the durability of the prototype product used in the study are necessarily limited in scope as the testing was not conducted in accordance with EPA test procedures and was conducted on EPA Phase 2 cer tified product. EPA Phase 3 has been in effect since 2011, with more stringent em ission standards and a useful life category which is now double for the study prototype. To better understand and assess the impact of the employed technology in the NIST st udy additional information on how and where the thermocouples for measuring temperature were installed should be provided for both the modified and unmodified test units. PGMA is requesting that this information be
made available for review.

Even if the technical challenges could be overcome, one would not be surprised to find that there is a significant delta between the cost to manufacture the product on the market today and products that incor porate the technology used with the prototype model. The portable generators on the market today perform a valuable function for consumers, especially during power outages. The limited av ailability of new produ ct or a significant cost delta will result in this option no l onger being a viable alternative for many

consumers.

As the leading trade association of manuf acturers of portable generators, PGMA is engaged in many activities promoting the safe use of its products. For example, PGMA has worked with the National Association of Regulatory Utility Commissioners to standardize the CO message being delivered via the utility industry’s various forms of communication so that it can be clearly and e fficiently provided to consumers. Reducing the number of portable generato r related CO incidents that occur after a utility company shuts off the power, due to nonpayment for example, shows promise and this effort could be enhanced by the CPSC’s participation. We invite CPSC to work with PGMA collaboratively as othe r opportunities arise.

Very Truly Yours,

JOHN H. ADDINGTON
Executive Director
PGMA JHA/jlb

pgmaFrom: CPSC-OS,

To: Buyer, Janet Subject: FW: Comments to CPSC on NIST Technical Note 1781

Date: Wednesday, May 29, 2013 11:42:50 AM

Attachments: image001.png image002.png Importance: High

Todd Stevenson Director, The Secretariat (Office of the Secretary)
Office of the General Counsel US Consumer Product Safety Commission (301) 504-6836, Fax (301) 504-0127

From: Jim Nice [mailto:jim.nice@kiporpowersystems.com]
Sent: Tuesday, May 28, 2013 11:27 AM
To: CPSC-OS, Subject: Comments to CPSC on NIST Technical Note 1781 Importance: High



### Comments to CPSC on NIST Technical Note 1781

Always use generators outdoors, away from doors, windows and vents.

NEVER use generators in homes, garages, basements, crawl spaces, or other
enclosed or partially enclosed areas, even with ventilation

. Follow manufacturer's instructions to operate generators in a well-ventilated

area.

Install battery-operated or plug-in (with battery backup) carbon monoxide (CO)
alarms in your home, following manufacturer's instructions.

Test CO alarms often and replace batteries when needed.Even with the “modified” generators, which was never thoroughly explained what or how the generators were modified; the CO levels were still excessive. It would have been interesting to see a comparison of the generators being operated in a proper
manner outdoors and see what the CO levels were within the house.

In considering any “rule-making” changes, one of the major considerations should be the cost to the manufacturer and eventually to the end user. Perhaps the most economical and beneficial changes would be to have a reasonable sized decal (label) place on the unit with contracting colors, warning of the danger of operating the generator in enclosed spaces.

Respectfully,

Jim Nice National Technical Services Manager Kipor Power Systems 12021 NE Airport Way, Suite G Portland, OR 97220
503-445-0197 X 304 www.kiporpowersystems.com1 6/7/13

Comments to CPSC on NIST Technical Note 1781

From Albert Donnay, MHS, adonnay@jhu.edu Submitted to cpsc

- os@cpsc.gov

Thank you for making this report available for pu blic comment.

It is my professional opinion as a certified CO analyst [BPI], environmental health engineer and consulting toxicologist that this NIST study and the Technical Note that describes its results should not be relied upon by CPSC for any rulemak ing related to portable generator safety.

The primary problem with the NIST study is that it only tested CPSC’s modified and unmodified portable generators in a single 1500 sq ft pre

- manufactured house whose design, layout and
construction are not representative of most US single family housing [SFH]

.

Although over 75% of SFH i n USA have attached garages [AG] according to the National Association of Home Builders, they are very different f rom that built by NIST for CPSC.

Most SFH with AG were d esigned and built simultaneously by the same builder using the same materials with plans from the same architect. As a result, the wall they share is an interior one with no windows, little or no insulation, and sometimes even unfinished on the garage si de with studs showing . The connecting door is commonly also of interior quality, rarely solid, and not as tightly sealed as doors leading outside.

If one story, the house and garage commonly share the same roof line, and if without basement, they commo nly share the same floor, although the house floor is usually raised at least a few
inches if not feet to prevent spills from entering the rest of the house.

In sharp contrast, t he AG in the NIST test house was added in 2007, 5 years after the original
h ome was built for a different study that involved greatly ‘tightening’ the house against air leaks
to the outside (Nabinger and Persily 2008

, NISTIR 7478 ).

It was added on to an ext ernal end wall that already had a tight window, tight exterior door, and
exterior siding . Instead of matching the end wall and roof line, however, it w as built with a higher floor, narrower width, and taller roofline

.

This NIST note [#1781 ], like Emmerich’s interim report to CPSC of July 6, 2011

, gives only the

square footage and volume for the garage and house, from which the average heights of each can be calculated by simple division as 2.5 and 2.4 met ers respectively, but the graphics in figure 2 of NIST note 1637 [ Wang and Emmerich 2009 ] clearly show the shared wall is much higher than this, with the garage roof extending more than 0.1m above the roof of the house. Why was it not built to match? NIST refused multiple requests to answer this question, and also refused to release any photo of the shared wall fro m within the garage. The report does show pictures of the inside of the shed, so why not the inside of the garage?

Any CO rising in the garage would naturally rise higher than the house and result in less CO diffusing into other rooms or the attic than i f they shared a wall that was the same height and width from floor to ceiling. The higher garage floor also would reduce the opportunity for rising CO to enter the house since the critical floor/wall seam on the house side was below the level of the garag e floor.

The NIST test house is thus not a sufficiently representative design for such an important evaluation upon which the lives of all Americans with portable generators may depend.2 COMMENTS OF DONNAY ON NIST 1781, PAGE 2 OF 2

The second proble m is that CPSC’s portable generators were tested without any reference to whether the engines were hot or cold when started.

The authors told me that they did not control for engine startup temperature, and so it is impossible now in retrospect to know which of their experimental runs were done with appropriately cold engines [representative of the most likely worst case exposure scenario for
the home user] and which were done with done with already warm or hot engines [ whose CO
emissions would be lower]

.

I also note with great concern that the authors never measured how long it took for the CO

contaminated test house to return to the baseline CO level with only natural ventilation, as would be the case in most SFH during generator use when no other sou rce of electricity is likely available, but instead turned on mechanical ventilation to speed up the process. Without this information, it is impossible to estimate how long the occupants of a SFH whose portable generator had just automatically shut off might be exposed to just how much CO while they waited [without mechanical ventilation] for the CO in their garage and other rooms to return to a safe level.

Finally, and most critically, the CO levels reported in Appendix C on Additional Garage Tests
cle arly document that even when the shutoff algorithm worked, the maximum CO level in the

garage was in the range of hundreds of ppm. This is far above all levels considered safe by all federal agencies, including the : 1) 9 and 35ppm avg limits of EPA [for 8 an d 1 hour exposures, respectiv ely, equivalent to 72 and 35ppm

- hours] ; 2) 35 ppm avg limit recommended by NIOSH for healthy workers and the level at which most fire departments in USA require firefighters to put on their self contained breathing apparatus a nd order the evacuation of any building 3) 50 ppm avg limit allowed by OSHA 4) 70 ppm limit allowed by CPSC

Rather than continue to pursue this complicated, expensive and ultimately ineffective approach to shutting off portable generators, I urge CPSC to requi re only a CO

- sensing shut off device. Staff have already tested such an approach [2006] and CPSC should release their report so that their findings can be evaluated by the public and portable generator manufacturers before any new rule or is proposed.

Given that over 25 million high quality long lasting CO

- sensing switches are sold to the auto industry ever year for approximately $5 each and have been for over a decade, it is outrageous that CPSC has still not even studied the potential of these devices

.

They function reliably for 10

- 15 years, even in cars that are left outdoors all the time, and could easily prevent not just the CO deaths caused by portable generators but also the no doubt much higher number of CO poisonings that clearly cannot be pr evented if relying only on electronic
emission controls and non

- CO sensors.

Thousands of Americans have died needlessly since CPSC started this project 7 years ago.
Please do not allow this to continue.

# # #1 Written Comments of the Manufacturers of Emiss ion Controls Association (MECA) on the National Institute of Standards and Technology’s (NIST) R eport, “ Technical Note
1781: Modeling and Measuring the Effects of Portable Gasoline Powered Generator
Exhaust on Indoor Carbon Monoxide Level ”

June 7, 2013

The Manufacturers of Emission Controls Association (MECA) is pleased to provide our

comments to the U.S. Consumer Product Safety Commission (CPSC) on the National Institute of Standards and Technology’s (NIST ) report, “ Technical Note 1781: Modeling and Measuring t he
Effects of Portable Gasoline Powered Generator Exhaust on Indoor Carbon Monoxide Level

. ”
MECA is a non

- profit association of the world’s leading manufacturers of emission control technology for m otor vehicles and stationary internal combustion engines. Our members have nearly 40 years of experience and a proven track record in developing and manufacturing emission control technology for a wide variety of on

- road and nonroad vehicles and engines. A number of our members have extensive experience in the development, manufacture, and commercial application of carbon monoxide ( CO ) emission control technologies for stationary engines, as well as expertise in applying catalyst technologies to small

, spa rk

- ig nited engines less than 25 hp.

MECA has been engaged in CPSC’s efforts to improve the safety of portable generators in marine and domestic applications by reducing the level of CO emitted by these small, spark

ignited four

- stroke engines. MECA has previously provided comments to CPSC about the available technology for portable generator applications in response to CPSC’s request for information on techniques to reduce CO from gasoline portable generators (MECA letter dated April 28, 2 006), MECA ’s written comments on CPSC’s ANPRM on portable generators ( comments dated February 11, 2007), and MECA’s written comments on CPSC’s September
2012 test report, “Technology Demonstration of a Prototype Low CO Emission Portable Generator” ( comments dated No vember 7, 2012). Our comments below mirror the comments
we submitted t o C P S C back in November.

The new report by NIST describes a series of tests performed for CPSC on generators in commercially available and modified low CO emission prototype configurations to determine their CO emission and oxygen consumption rates while operating in a single

- zone enclosed space. For two different unmodified commercially available generators (i.e., with carbureted engines lacking CO

- emission controls), CO emissions ranged from a low of around 500 grams per hour (g/hr) at near ambient oxygen levels to a high of nearly 4 000 g/h as oxygen approached
17 %. Tests of two modified, low CO emission prototype generators (i.e., commercially available units adapted with closed

- loop elect ronic fuel injection and a small catalyst integrated into the muffler) showed CO emissions reductions of over 90 % with most CO emission rates well below 500 g/hr, and no trend toward higher emission rates was seen as the oxygen level dropped.

Like CPSC’s September 2012 test p r o g r a m , t he results of the NIST s t u d y support the experience of catalyst manufacturers and the recommendations provided by MECA on the effectiveness of the use of catalysts to reduce CO emissions and improve the safety of portable

gen erators. Catalyst technology is a cost

- effective technique for substantially reducing CO2 exhaust emissions from spark

- ignited, gasoline portable generators. Catalyst technology for small gasoline engines like those used in portable generators draws from nearly 40 years of successful experience in the U.S. with catalytic converters applied to light

- duty gasoline cars and trucks. Similar catalyst technology has been successfully applied to a wide variety of smaller,

two

- stroke and four

- stroke gasoline engi ne applications

, including handheld equipment (e.g., chainsaws, leaf blowers, string trimmers), non

- handheld equipment (e.g., lawn mowers), motor scooters, motorcycles, marine engines, and forklift trucks. In many cases

, these catalyst systems
have been e ngineered to provide high reductions of CO emissions as well as reductions in hydrocarbon (HC) and NOx emissions. The U.S. EPA in its small engine test program that was completed in advance of their Phase 3 small engine regulations (published in October 2 008) clearly demonstrated that catalysts can be safely incorporated on Class 1 and Class 2 gasoline engines without any significant increase in muffler surface temperatures. MECA and MECA members were active participants in EPA’s small gasoline engine tes t program.

The published experience of catalyst performance on four

- stroke gasoline engines indicates that high efficiencies for reducing CO emissions are strongly influenced by the air/fuel stoichiometry in the exhaust upstream of the catalyst. Maximum reduction efficiencies for all three regulated pollutants ( HC s, CO, NOx) can be obtained if the air/fuel ratio of the exhaust
stream is controlled to be near the stoichiometric ratio of reducing and oxidizing components in the exhaust stream. At or near this stoichiometric air/fuel ratio, catalyst efficiencies can be well in excess of 90% for all three pollutants provided that the catalyst temperature is above its
activation te mperature (typically 350 o C or higher), and that a reasonable catalyst volume relative to the volumetric flow of exhaust gas is contained in the system. Catalyst formulations can be optimized for these small engine applications to deliver maximum CO reduct ions and/or NOx reductions depending on the final emissions target. Precious metal costs for these small engine catalysts are typically less than half the total cost of the finished catalyst. The addition of a catalyst to a small engine would have only a very small impact on the cost of a gasoline
generator.

The most widely used method for accurate, and cost effective, air/fuel ratio control is through the use of fuel injector technology in combination with a closed

- loop control strategy that employs a s imple engine control unit (ECU) and an oxygen sensor present in the exhaust, upstream of the catalyst. The sensor provides a feedback loop to the engine’s intake air and fuel metering system. The combination of closed

- loop, electronic fuel injection with a catalyst reduces engine

- out emissions and ensures consistent engine operation. This more stable, reduced engine

- out emissions operation reduces the thermal stress on the catalyst and improves the catalyst durability. Such an approach has been applied to a whole range of spark

- ignited engines from passenger cars to handheld lawn and garden equipment

, a n d t h i s i s t h e s a m e a p p r o a c h t h a t

was effectively demonstrated on the two modified, low CO emission prototype generators in the NIST study, as well as on the small gasoline

- powered porta ble generator in CPSC’s previous demonstration program.

MECA is aware of two manufacturers of four

- stroke, gasoline generators that are already using properly designed exhaust systems with catalysts to reduce CO emissions by more than 90% compared to unco ntrolled levels: Westerbeke Corporation and Kohler Power Systems. Both of these companies have targeted marine applications for these ultra

- low CO emission3 generators. The same strategy is applicable to portable generators for home use. MECA
believes t hat the ultra

- low CO emission generators offered by Westerbeke and Kohler employ the same type of strategy (controlled exhaust air/fuel ratio near the stoichiometric point) to achieve high CO conversion efficiencies across a catalyst as documented in the s ubject report.

In summary, similar to CPSC’s September 2012 test program , the commission has effectively demonstrated in the NIST study that catalyst

- based exhaust emission controls are a
proven, cost

- effective, durable, and safe strategy for reducing CO emissions from small, four

stroke gasoline engines like thos e used in portable generators. The combination of precious
metal

- based, three

- way catalyst formulations and precise air/fuel control has been shown to provide CO conversion efficiencies well in e xcess of 90% on a small

, four

- stroke gasoline engine in a portable home generator. We commend the commission on its ongoing work to
demonstrate the effectiveness of state

- of

- the

- art combustion controls in combination with catalyst technologies to reduce C O emissions f rom these generators. MECA continues to strongly support CPSC’s efforts in urging portable generator manufacturers to voluntarily implement these cost effective strategies to reduce CO emissions and improve the safety of home portable generators. In addition, i n the absence of a voluntary standard, MECA believes that EPA should strongly consider adoption of a mandatory, low CO emission standard for gasoline
generators.

CONTACT: Joseph Kubsh
Executive Director
Manufacturers of Emission Controls Association
2200 Wilson Boulevard
Suite 310 Arlington, VA 22201 Phone: (202) 296

- 4797 x107

E

- mail: jkubsh@meca.org