Table 1

Summary of early patents (before 1980) to produce fire safe cigarette

Patent feature	Description	Results	Number of patents
Source: Industry documents.¹⁹
Silicate additives	Added silicate to paper for reduced porosity	Decreases burn rate to self extinguish when unpuffed; increases total delivery	8

Sheath enclosure	Cigarette enclosed by foil, silicates, or other fire retardant substance	Fire safe, although cumbersome and considered “impractical for routine use”	4

Banded paper/ barriers	Band of non-combustible material in paper or tobacco	Terminates cigarette burning at predetermined point (self extinguishing)	15

Asbestos or glass in paper	Addition of fire resistant materials in paper	Materials not suitable for use in commercial cigarettes	4

Burn rate additives	Addition of additives to paper to reduce burn rate	Decreases burn rate to self extinguish when unpuffed; increases total delivery	2