Wednesday May 7, 1977 was a cloudy day in Gaithersburg, MD. Shortly before lunch that morning, several engineers and inventors entered building 202 on the National Bureau of Standards campus. They came from all over the country to present mower safety devices they’ve designed to the newly established Consumer Product Safety Commission (CPSC), created by the Consumer Product Safety Act (CPSA) signed into law by President Nixon 5 years earlier.¹

A month prior to this meeting, the CPSC voted to implement a new safety standard for power lawn mowers.² They were looking for the cutting edge in lawn mower safety technology, and hoped to find new safety ideas by meeting with individuals and manufacturers who were innovating in this realm. The ideas gathered at this meeting influenced parts of the new lawn mower safety regulation, known today as 16 CFR Part 1205: Safety Standard for Walk Behind Power Lawn Mowers.³

The origins of 16 CFR Part 1205 are quite convoluted. In August 1973, the Outdoor Power Equipment Industry (OPEI) petitioned the CPSC to adopt ANSI B71.1-1972, the most recent ANSI safety standard for power mowers, as the CPSC’s safety regulation for walk behind lawn mowers. But for reasons unknown, in October 1974, the CPSC instead contracted with Consumers Union (CU) of United States, Inc., today known as Consumer Reports, to propose their own regulation. The CPSC paid $66,745 to CU to develop the standard, in addition to another $25,000 for experimentation and testing.⁴

With these funds, CU conducted significant research to develop their proposed regulation. They organized time studies to see how fast an operator can move their hands from a power mower handle to underneath the mower deck. They examined the forces blade shields would encounter during typical mower operation. They gathered and compiled existing research on lawn mower injuries, combined it with their own research, and presented it to the CPSC along with their proposed regulation.

CU’s recommended regulation contained several detailed safety rules for preventing electrocution from mower electrical systems, burns from hot mower surfaces, hearing loss due to excessive mower noise, impact from debris thrown by the mower, shields for exposed mower blades, and mower start and stop controls, while addressing other safety issues.⁵

While the CPSC didn’t use every recommended rule written by CU, it did adopt several rules related to maximum blade stop time, mower start and stop controls, and mower shields and guards. These rules, in addition to new labeling and record keeping requirements, form the newly promulgated 16 CFR Part 1205, which was placed in the Federal Register on February 15, 1979, with an effective date of June 30, 1982.³

But before the new regulation could go into effect, the OPEI sued the CPSC. In Southland Mower v. Consumer Product Safety, the OPEI’s lawyers make any and every argument they can think of to nullify, neuter, or otherwise delay the regulations in 16 CFR Part 1205.⁵ They argue that lawn mowers are not consumer products, and hence the CPSC does not have authority to regulate them. They argue that there is insufficient evidence in favor of a safety regulation, and that it violates the CPSA. They argue that new shielding requirements will be defeated by consumers and are not efficacious in promoting safety. The majority of their arguments are pedantic and relate to interpretation of the language of the CPSA and how it pertains to 16 CFR Part 1205.

The case is heard by the Fifth Circuit Court of Appeals, and on June 19, 1980 they hand the OPEI a sound defeat based on the CPSA’s broad language allowing it to regulate, well, consumer products. It does, however, throw the OPEI a bone by vacating a portion of the regulation’s foot probe requirement, stating insufficient evidence exists to prove it will reduce foot injuries as a result of contact with a rotating mower blade.

Within the text of 16 CFR Part 1205, the CPSC notes that many mowers on the market in 1980 already feature the safety devices mandated by the regulation. In effect, the regulation codifies what most manufacturers are already doing regarding mower deck shields and controls, but includes new record keeping and safety labeling requirements. And, as with all regulations issued by the CPSC, there are new penalties for non-compliance.

The CPSA mandates safety regulations define performance requirements⁶, not design requirements. The idea is that regulations should promote multiple creative solutions to a safety problem, not mandate a single specific solution. But 16 CFR Part 1205 mandates the geometry of shields and the specific location of mower controls. There are only so many ways you can design a shield or locate a dead man switch to satisfy the regulation.

And as a result, innovation in the power mower realm decelerates after the 16 CFR Part 1205 goes into effect. In many ways, the regulation froze the state of the art in safety technology for mowers in the early 1980’s. Power mowers manufactured today are remarkably similar to those made from that era.

With decades of injury data to examine, an argument can be made that 16 CFR Part 1205 hasn’t even improved mower safety. At the time it was issued, the CPSC estimated 77,000 mower related injuries occur annually. Between 2005 and 2015, that number is estimated at more than 84,000 annually.⁷ The severity of these injuries may be less, but as an empirical fact, more people are injured by power lawn mowers today than before the regulation was put into effect.

One can only speculate what the inventors who met to showcase their safety innovations in Gaithersburg, MD would have thought about the resulting safety regulation their ideas influenced. But it’s a safe bet each of them would probably agree: if you want to prevent mower injuries, find a way to separate the operator from the mower. Next time I’ll talk about how 16 CFR Part 1205 makes that difficult, and how the regulation has influenced mower design ever since its inception.

References

1. CPSC Invites Inventors of Lawn Mower Safety Devices, CPSC.gov, 11/16/19.
2. CPSC Seeks Offerors to Develop Mandatory Power Mower Safety Standards, CPSC.gov, 11/16/19.
3. 16 CFR Part 1205, govinfo.gov, 11/16/19.
4. CPSC Accepts Consumers Union Offer to Develop Power Lawn Mower Safety Standard, CPSC.gov, 11/16/19.
5. Southland Mower v. Consumer Product Safety, 619 F.2d 499 (5th Cir. 1980).
6. Consumer Product Safety Act, Section 7(a)(1), CPSC.gov, 11/16/19.
7. Lawn mower injuries presenting to the emergency department: 2005 to 2015. NCBI, 1/10/18.