Many people have been injured while processing bho on a small scale for personal use. Some have died during the manufacture of bho, and other horrific injury's have occurred so some simple steps must be taken to ensure the product is safe to make and safe for the consumer.I will outline these steps below. Some potential dangers: 1.Butane exposure past regulatory limits (Depending on ventilation) 2.Explosion 3.Fire 4.Tube blowout (Material is shot out of tube from pressure) 5.Dirty unsafe or contaminated end product In order to eliminate #1 good ventilation is necessary. When using an open system (Glass tube,sstb,pvc) do the following to reduce the chance of 2 and 3 occurring: Absolutely no smoking or ignition source of any kind Always spray outdoors, no exceptions. Always use adequate ventilation. Static is a possibility, make sure you wear clothing that accounts for this and also adjust the flooring of your spray area if needed. Always evaporate any and all liquid butane outside.Pop some of the larger bubbles before you bring it inside if you wish to be cautious. In order to eliminate the chance of 4 occurring you need to use a sufficient clamp and mesh/silkscreen setup. Never spray with just coffee filters. In order to make the extraction efficient and of high quality the pressure within the tube needs to get as high as possible without becoming a danger. As an extra precaution always wear safety glass's. Eliminating 5 is really up to whoever cooks the product.Fully wash the tube and pan before use. Dont use cheap butane.I personally prefer vector and feel it's one of the only safe commercial butane brands.I do not care what brand butane you use as im not trying to push vector, but dont ask why your product comes out tasting like sulfur or worse when using cheap butane. You realy do get what you pay for in my opinion.Also always process bho in a sterile environment. PREP: Grind material for best yield/more efficient extraction.(Break up into small chunks or use small buds for higher purity)Cut 1 or 2 coffee filters to the proper size for your tube.(As to minimize the oil lost to the filters)Use a tube that is up to specs. For smallish amounts it should be no more than 3/4 inch diameter.For 3/4 di the tube should be 10-12' long.Get a wooden dowel, drumstick or anything else you can pack your tube with.Make sure it fits snug so you can pack it properly.Take the material after its ground and put it all in the tube at once without packing it down.I prefer a heavy wall glass tube for extractions.Take dowel/drumstick ect. and put in tube, pack all material at once. Pack the tube as tight as possible. You can push the drumstick/dowel against the floor for leverage just be sure you dont break the glass or the packing tool.You want it packed as tight as possible.Secure clamp and filters. Tighten clamp as to ensure it will hold during the high pressure of the extraction.The higher the pressure the better the product. EXTRACTION: Take outside. Lay pyrex dish in 95-105F water or oil(to prevent condensation). Change as needed. Insert butane can into tube. Apply lots of pressure on the can.Hold over center of pan. Let tube being to pressurize (It will if everything was done properly).You will hear a loud pop, and a splatter of oil will hit the pyrex. Make sure the tube is at the proper height or it can splash into the water. This is a large amount of the final yield. You can stop here if you choose and spray into a separate pyrex. The less butane you put into the product in the first place the easier it is to purge out. This is really only recommend for beginners, but will allow you to make a high quality oil fairly easily if your not experienced. Allow liquid butane to fully evaporate. Bring inside. Place on warm water (90-110F). The warmer the water the faster you can purge. When you pass a certain temperature you start to degrade active compounds, and at another (lower) temp terpens start being released at an extremely fast rate. I personally would never at any point of the purge put it in water that's even 125F but to each is own.When you get into the mid 100s terpens start to decay very fast. If you get close to 200F during the purge you will start to degrade cannabinoids at a fast rate.I recommend 90-110F the entire purge and i suggest you check your water with a thermometer.Keeping the water at a stable temp is key. In general one a half grams of oil (a quarter) takes 2-2 1/2 hours to fully purge on water.You can use cold baths to prevent terpens from escaping once enough butane has evaporated if you wish.If you want to be extra cautious you can purge for 3-4 hours but there will be allot more degradation then necessary If you are concerned about butane in the end product (The amount will be negligible in the end product anyway) let it sit spread out in a concentrate dish for a couple days.When using the cold water baths put the dish on warm water first and move it back and forth between the two every 10 mins or so(Adjust the time as needed).You do not want to use cold water bath while the product is still loaded with butane.This will trap the butane in the oil.The reason you cold water purge in this way is it causes expansion and contraction to occur, allowing butane to escape the oil as it expands and contracts.You must whip it and have it spread thin during this process for it to work optimally. If you are still worried about butane residues you can spread the oil very thin during the final steps of the purge.This will remove any visible bubbles. During the final step of the purge if you are having problems getting a nice consistency leave it on cold water for 15-30 mins as a last step before it goes in a dish.Whip it while it sits on cold water.You should be left with a nice product of a budder like consistency that smells and tastes great with negligible butane residue.