There are numerous issues confronting defense counsel and prosecutors in this arena – including (but not limited to), the type of equipment used, procedures employed by law enforcement and lab personnel, the physical condition of the test subject, chain of custody and numerous scientific criteria. Breathalyzer 900, 900A, 1000 and 2000 – one of the most common breath test machines which utilize a wet chemical method of breath analysis rather than infrared spectrophotometry. Although this machine has long been discontinued, it is still in use in many jurisdictions, particularly rural areas. One of the chief problems with the Breathalyzer is that it is nonspecific to alcohol. In other words, any volatile organic substance, such as turpentine, may register as blood alcohol. In addition, all Breathalyzer models but the 900 are susceptible to radio frequency interference.