On 2016 May 20, Clive Bates commented:

The paper raises well-known fire and explosion risks from lithium-ion batteries, which arise in any products that use them. However, the paper goes on to draw an inappropriate and alarmist conclusion that e-cigarettes constitute a "significant public health risk" on the basis two case studies and four inconclusive media reports.

The problem is that they apply this alarming label without defining what constitutes a significant public health risk, a concept that must depend on the magnitude of the risk involved and how this compares to other risks.

Comparison to smoking-related accidents and injuries

The most important feature of e-cigarettes is that they are alternatives to smoking cigarettes. The authors have not made a comparison with smoking-related accidents or injuries (let alone disease) or made an estimate of the net impact that arises from consumers who switch from smoking to e-cigarette use. The accidents and injuries associated with smoking do actually appear like a "significant public health risk". The U.S. National Fire Protection Service provides useful data:

In 2011, U.S. fire departments responded to an estimated 90,000 smoking-material fires in the U.S., largely unchanged from 90,800 in 2010. These fires resulted in an estimated 540 civilian deaths, 1,640 civilian injuries and $621 million in direct property damage; deaths were down substantially from the year before.

Home structure fires dominated all these measures of loss except for fire incidents. In 2011, an estimated 17,600 smoking-material home structure fires caused 490 civilian deaths (19% of all home structure fire deaths), 1,370 civilian injuries and $516 million in direct property damage. The other 72,400 smoking-material fires in 2011 were mostly outdoor fires (60,200 fires in trash, vegetation and other outdoor combustibles).

Comparison to other risks

Some broader context may be useful - each year there is one significant injury episode for every eight Americans. U.S. data from CDC:

Morbidity

Number of medically attended injury and poisoning episodes in the population: 39.5 million

Episodes per 1,000 population: 126.3

Mortality

Number of injury deaths: 192,945

Deaths per 100,000 population: 60.2

Just about every practice in everyday life involves some risk: cooking, eating, walking, showering, using a laptop, walking up stairs, anything that involves electricity, heat or glass etc.

For example, according to the U.S. National Fire Protection Service home grills account for damage and injuries as follows:

In 2009-2013, U.S. fire departments responded to an average of 8,900 home fires involving grills, hibachis, or barbeques per year. These 8,900 fires caused annual averages of 10 civilian deaths, 160 reported civilian injuries, and $118 million in direct property damage. Almost all the losses resulted from structure fires

How does the e-cigarette compare to the ubiquitous and much-loved BBQ?

There are also persistent reports of exploding iPhones. Should iPhones be designated a "significant public health risk"?

Conclusion

Claims that products or behaviours cause significant public health risks need to be proportionate and reflect both absolute risks (how much harm is caused) and relative risks - i.e. set in appropriate context by reference to risks arising from other common products and activities. Risk is a quantitative concept or it is meaningless.

The authors did not reflect on whether there is a net public health gain in terms of accident risk through the substitution of smoking by e-cigarette use, which is by far the most common pattern of use. It is irresponsible to draw attention to one risk associated with a behaviour, without considering whether it reduces more significant risks. Given the rarity of e-cigarette battery incidents and the preponderance of smoking-related fires, it seems more likely that the net impact on accidents through e-cigarette use will be a significant reduction and therefore a public health win.

This is not a call for complacency but for proportionality. Regulators could have addressed fire risks from e-cigarette batteries some years ago, but have been spending their time on grandiose and excessive regulatory schemes that have yet to achieve anything and may not even solve this problem when they finally apply.

On 2016 May 20, Clive Bates commented:

The paper raises well-known fire and explosion risks from lithium-ion batteries, which arise in any products that use them. However, the paper goes on to draw an inappropriate and alarmist conclusion that e-cigarettes constitute a "significant public health risk" on the basis two case studies and four inconclusive media reports.

The problem is that they apply this alarming label without defining what constitutes a significant public health risk, a concept that must depend on the magnitude of the risk involved and how this compares to other risks.

Comparison to smoking-related accidents and injuries

The most important feature of e-cigarettes is that they are alternatives to smoking cigarettes. The authors have not made a comparison with smoking-related accidents or injuries (let alone disease) or made an estimate of the net impact that arises from consumers who switch from smoking to e-cigarette use. The accidents and injuries associated with smoking do actually appear like a "significant public health risk". The U.S. National Fire Protection Service provides useful data:

In 2011, U.S. fire departments responded to an estimated 90,000 smoking-material fires in the U.S., largely unchanged from 90,800 in 2010. These fires resulted in an estimated 540 civilian deaths, 1,640 civilian injuries and $621 million in direct property damage; deaths were down substantially from the year before.

Home structure fires dominated all these measures of loss except for fire incidents. In 2011, an estimated 17,600 smoking-material home structure fires caused 490 civilian deaths (19% of all home structure fire deaths), 1,370 civilian injuries and $516 million in direct property damage. The other 72,400 smoking-material fires in 2011 were mostly outdoor fires (60,200 fires in trash, vegetation and other outdoor combustibles).

Comparison to other risks

Some broader context may be useful - each year there is one significant injury episode for every eight Americans. U.S. data from CDC:

Morbidity

Number of medically attended injury and poisoning episodes in the population: 39.5 million

Episodes per 1,000 population: 126.3

Mortality

Number of injury deaths: 192,945

Deaths per 100,000 population: 60.2

Just about every practice in everyday life involves some risk: cooking, eating, walking, showering, using a laptop, walking up stairs, anything that involves electricity, heat or glass etc.

For example, according to the U.S. National Fire Protection Service home grills account for damage and injuries as follows:

In 2009-2013, U.S. fire departments responded to an average of 8,900 home fires involving grills, hibachis, or barbeques per year. These 8,900 fires caused annual averages of 10 civilian deaths, 160 reported civilian injuries, and $118 million in direct property damage. Almost all the losses resulted from structure fires

How does the e-cigarette compare to the ubiquitous and much-loved BBQ?

There are also persistent reports of exploding iPhones. Should iPhones be designated a "significant public health risk"?

Conclusion

Claims that products or behaviours cause significant public health risks need to be proportionate and reflect both absolute risks (how much harm is caused) and relative risks - i.e. set in appropriate context by reference to risks arising from other common products and activities. Risk is a quantitative concept or it is meaningless.

The authors did not reflect on whether there is a net public health gain in terms of accident risk through the substitution of smoking by e-cigarette use, which is by far the most common pattern of use. It is irresponsible to draw attention to one risk associated with a behaviour, without considering whether it reduces more significant risks. Given the rarity of e-cigarette battery incidents and the preponderance of smoking-related fires, it seems more likely that the net impact on accidents through e-cigarette use will be a significant reduction and therefore a public health win.

This is not a call for complacency but for proportionality. Regulators could have addressed fire risks from e-cigarette batteries some years ago, but have been spending their time on grandiose and excessive regulatory schemes that have yet to achieve anything and may not even solve this problem when they finally apply.