They didn’t even do that, though. They said “I don’t like my options for fire retardant, so here’s how I built a mattress without it”, with zero justification for why they thought it was acceptable, zero assurances that they put any thought into it.
It is a personal, minimalistic blog that someone else submitted to HN. The argument that the bed fire risk comes mostly from smoking in bed seems straightforward so maybe they did not feel a need to spell it out.
While on the topic of fire hazards "[s]heep farming emits high volumes of methane, a potent greenhouse gas, and also drives carbon-emitting deforestation"[0] both which, I add, contributes to climate change which increases the likelihood and impact of forest fires which put human lives at risk.
[0] https://www.vox.com/future-perfect/24008053/wool-marketing-e...
> But while smoking materials continue to be the leading source of deadly home fires, incidents involving candles have steadily increased. Candle fires have quadrupled to 16 400 a year over the last decade
https://www.flameretardants-online.com/news/archive?showid=1...
If the author of the article doesn't smoke in bed, then they are circumventing the risk in a different way.
In the UK, the label that shows soft furnishings are fire retardant has a picture of a cigarette and match, which is what leads me to believe this was the primary risk.