"professional" Ektachrome process for sheet film and Kodak EP professional rollfilm (1959 to 1976) E-4 Updated Ektachrome process for roll film and 135 film (1966–1996, see note) E-4 was better at resisting fading than the earlier processes, with a life around 30 years. E-5 Research project, only saw minor use in a revised form as the aerial film process AR-5 E-6 Current Ektachrome process used for all major color reversal films and formats, first released in 1977. The conditioner, bleach and stabilizer baths were modified in the mid-1990s to remove the formaldehyde from the stabilizer: This change was indicated by changing the names of the conditioner step to pre-bleach step, and the stabilizer step to the final rinse step; E-6P: Used for push processing of Kodak Ektachrome films in general, and particularly for Kodak Ektachrome EPH ISO 1600 film, which has a speed of ISO 400 in normal E6, but is exposed at EI 1600 and push processed two stops in the first developer bath (10:00 @100.0 °F) to achieve the ISO 1600 speed rating. (It is natural for a faster film to require a longer first development time. This is sacrificed in the case of most color processing for consistency in processing, especially in machine processing.) Other film manufacturers use their own designations for nearly identical processes. They include Fujifilm's process CR-55 (E-4) and CR-56 (cross-licensed with Kodak's process E-6; but with slight variations in the first developer); and the now-discontinued Agfachrome and Konica's CRK-2 (E-6 equivalent). The E-4 process was generally discontinued after 1977, although continued in use for Kodak PCF (Photomicrography Color Film) until the 1980s, and for Kodak IE (Color Infra-red film) until 1996. This was due to a legal commitment by Kodak to provide the process for 30 years. The Ektachrome process differs significantly from the Agfa Process AP-41, used generally until 1983 to develop films such as Agfachrome CT18 and 50s Professional. Processing laboratories The Washington (W) Processing Lab operated between 1967 and July 1999. The lab facility was located in Montgomery County at the address of 1 Choke Cherry Road, Rockville, Maryland. The Palo Alto (P) California Processing Lab was located at 925 Page Mill Road, Palo Alto, California. The Rochester (R) New York Processing Lab was located at Kodak Park in Rochester, New York. There were also Kodak processing laboratories in other locations, including Chicago, (Illinois), Hollywood, (California-H), Atlanta (Georgia), Findlay (Ohio),