BHO Safety Warnings
Why making butane hash oil at home causes explosions and severe burns, what the burn-unit data shows, and safer ways to get concentrates.
Growing, buying or possessing cannabis and seeds is legal only in some places. Check the law where you live before acting on this information.
Making butane hash oil at home is one of the few cannabis activities that regularly puts people in burn units. Butane gas pools invisibly and ignites from everyday sparks, and the person extracting is usually standing in the fire. No checklist makes open blasting safe, and in many places it is a separate crime even where cannabis is legal. If you want concentrates, buy lab-tested products or use solventless methods such as rosin or ice-water hash.
What BHO is
Butane hash oil (BHO) is a cannabis concentrate made by dissolving cannabinoids and terpenes out of plant material with liquid butane (sometimes blended with propane) and then removing the solvent. Depending on processing, the result is sold as shatter, wax, budder, live resin, sauce or diamonds (see sauce extraction and THCA crystallization). Licensed processors make it in certified closed-loop systems inside rooms built for flammable gases.
"Open blasting" — pushing butane through a tube of plant material in the open air — is the method behind most home BHO accidents.
Why home extraction is so dangerous
Butane is stored as a liquid under pressure and turns into a large volume of gas the moment it is released. The gas is heavier than air, so it pools near floors, in sinks and in enclosed rooms rather than dispersing. It is invisible and has little smell of its own. Any ignition source — a pilot light, a fridge or freezer compressor, a light switch, a phone or static electricity — can set off a flash fire or explosion across the whole room [1] Strong evidence.
Because the vapour is spread through the space, the person doing the extraction is usually inside the fire when it ignites. That is why burns from BHO accidents typically cover large areas of the face, hands and body [2][3] Strong evidence.
What burn-unit data shows
- At a Colorado burn centre, 29 patients were admitted with BHO burns between 2008 and 2014: none before medical cannabis was liberalised, 19 during the medical-market years and 12 in 2014 alone, after recreational legalisation [1] Strong evidence.
- A California burn centre reported eight patients with burns covering 16% to 95% of their body surface, averaging about half [3] Strong evidence.
- A seven-year review of BHO burns at another centre described them as a growing problem [2] Strong evidence.
Explosions can also injure neighbours and first responders and destroy homes.
There is no safe way to do it at home
Checklists of "precautions" for home blasting give a false sense of control. A household space cannot be made safe for releasing pressurised butane: you cannot see or measure where the gas has collected, and you cannot remove every ignition source from a home, garage or garden. Licensed facilities rely on engineering controls that a home cannot reproduce — certified closed-loop equipment that keeps the solvent contained, rooms rated for flammable gases with continuous gas detection, explosion-proof electrics and ventilation, fire suppression, and inspections under local fire codes.
Weedpedia does not provide extraction instructions for butane, propane or other solvent methods.
The legal layer
Cannabis legality and extraction legality are separate questions. Many US states and other countries treat making concentrates with flammable solvents as its own offence, even where cannabis possession or home growing is legal. Colorado, for example, created a specific crime of manufacturing marijuana concentrate with an "inherently hazardous substance" [4] Strong evidence. Insurance policies and leases often exclude damage from such activity. Check the law where you live before processing cannabis in any way.
If you want concentrates
- Buy from licensed producers. Their products are tested; read the certificate of analysis for potency and residual solvents.
- Use solventless methods. Rosin uses heat and pressure, and ice-water hash uses cold water and agitation. Neither involves a flammable solvent.
If an accident happens
Call emergency services immediately. Do not re-enter a room where gas may remain, and do not try to treat large burns at home: burns from flash fires need specialist care [2].
Sources
- Peer-reviewed Bell, C., Slim, J., Flaten, H. K., Lindberg, G., Arek, W., & Monte, A. A. (2015). Butane hash oil burns associated with marijuana liberalization in Colorado. Journal of Medical Toxicology, 11(4), 422–425.
- Peer-reviewed Romanowski, K. S., Barsun, A., Kwan, P., et al. (2017). Butane hash oil burns: a 7-year perspective on a growing problem. Journal of Burn Care & Research, 38(1), e165–e171.
- Peer-reviewed Honey oil burns: a growing problem. Journal of Burn Care & Research (2015). PubMed record 24823328.
- Government Colorado Revised Statutes § 18-18-406.6 — Unlawful manufacture of marijuana concentrate using an inherently hazardous substance. Colorado General Assembly.
How this page was made
Generation history
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