I just got a 55 gallon drum of what is called Deep Well Drip Oil, ISO 32. Last year I used this heavily for 6 months in an 18 inch Frantom saw and it performed great. ISO 32 is the equivalent of 10 weight motor oil. This oil is considered a heavy machine oil for high power and hydraulic equipment. It has many excellent properties, anti-foam, anti-rust, constant viscosity at low to medium temperatures. It was under $7 / gallon delivered. This oil is very clear and has no smell I can detect!
Here is a link to some similar oil so you can read the characteristics of the Drip Oil.
http://www.lsc-online.com/deep-well-antiwear-pump-oil/ This drip oil stays very fluid even in cold weather. It still worked well on the hot days but it never got over 80 degrees here in sunny northwest Oregon.... Recycling the oil was easy. The rock particles separated to the bottom of the saw and formed a hard mat of guck. Most oil was recovered during draining. The rest was easily filtered using paper bags.
There are many ISO 32 oils on the market and each one is different. You need to check the additive list!!! The oil I found has no toxic additives, many of them do. You can even order some types of ISO 32 oil at WalMart for $6 a gallon. This is not a recommendation, just information. Due diligence and some help with any other info from other members would be appreciated.
PS: Mineral oils like this are highly refined petroleum oils and are still considered hazardous. Unless the oil is marked "Food Grade Oil, safe for consumption" you should consider it is not meant to be put in the landfill. Call your waste pick-up folks and ask them as it can vary in different areas. Mineral oil is still hazardous / toxic waste. VEGETABLE Oil or canola oils are different and not considered hazardous waste.