In the 1990s there was also growing concern about the transmission of disease by sharing a mouthpiece, particularly as a better option was available at a reasonable cost. "Dive Training" magazine ran an article by Alex Brylske in November 1993 detailing the hazards of buddy breathing and the advantages of alternative systems, and over the following years the practice was phased out of most recreational diver training programmes in favour of the use of secondary second stages and where applicable, a controlled emergency swimming ascent. Most recreational and professional diver training organisations would consider relying on buddy breathing from a single regulator as an unacceptable risk, as the use of a secondary demand valve (octopus) or second regulator, either from an alternative scuba cylinder, or from the primary scuba set, is a far more reliable and safe method of supplying emergency air to a diver who is part of a planned team or buddy dive, and a solo diver should carry his/her own emergency gas supply. There should never be a situation on a well planned and executed dive where two divers need to share a single demand valve, but the technique is still considered useful by some diving schools as it teaches control and hones skills under difficult circumstances. Buddy breathing is discouraged by many training agencies because other more reliable techniques and equipment exist. The technique needs training and regular practice by both divers if it is to be used successfully in a crisis; panic and task loading being the main reasons for it failing. Especially in situations in which one or both of the participants are not well-trained in the technique, the procedure has been criticised for endangering two people instead of one. Many divers fit a second demand valve, often called an "octopus", to their diving regulators, for emergency use by another diver. Some go so far as to recognise that the out-of-air diver will want the demand valve they are breathing off at the time, as it is indisputably providing breathing gas, and almost certainly a gas suitable for the current depth. These practice "" in recognition of this tendency, and often use an extra-long hose (up to 7 ft long) to facilitate the procedure in tight spaces. These divers often wear the secondary demand valve on a "" which keeps it ready for immediate use under the diver's chin, where it can be retrieved for use without the use of the hands. Divers doing deep diving, cave or wreck penetration, or decompression stops may routinely carry a complete, independent bailout scuba set for their own or their buddy's emergency use. This is particularly prevalent in professional diving operations where it is often mandatory.