Unvented Portable Kerosene Heater

Flueless kerosene or paraffin space heaters.

47Moderate burden · out of 100

Cleaner swapVented heating, or electric heaters with a window cracked

How this score is built

100Start
72.4Chemical hazard 6 × 4.6−27.6
52Everyday exposure 6 × 3.4−20.4
47Persistence 2 × 2.6−5.2, then rounded to 47
ModerateThe band47 sits in 40–59.

What each input rests on

The three ratings behind the score, and the studies each rests on
Input	Rating	Evidence
Chemical hazard	6/10	In a 27 m3 chamber study of unvented kerosene space heaters, both the semivolatile and the particle-bound organics they emitted were mutagenic in Salmonella typhimurium assays. Mutagenicity of organic emissions from unvented kerosene heaters in a chamber study · J Toxicol Environ Health 1992 DOI 10.1080/15287399209531629 · PMID 1608068 · Abstract · read 2026-10-06
Everyday exposure	6/10	unsourced input
Persistence	2/10	unsourced input

Ratings are editorial. A study listed here supports the rating; it did not compute it. How the index is built

What this means for you

The chemical-hazard rating is what drives the score down. Any unvented combustion appliance puts its entire exhaust — nitrogen dioxide, carbon monoxide and fine particles — into the room it is heating. Vented or electric heating removes the combustion products from the indoor air entirely.

Evidence strength: strong

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Lower-exposure choices

HEPA-Filtered Indoor AirMinimal · Air

All 13 air entries, highest burden first →