Many LED light manufacturers claimed that they offer LED light bulbs that can replace the 40W incandescent light bulbs. However, not all of them applied the same standard to claim so. In terms of luminous flux, a traditional incandescent bulb has a luminous efficacy of 11-12l/W, therefore, in order to replace a 40W incandescent bulb, the LED lamp bulb should reach 450 lm.
In areas such as United States, Europe and Japan, the substitution of traditional light sources with LED illumination must meet certain requirements, one of which is that the luminosity of LED bulbs has to be between 450 and 485lm. Compared to this standard, many LED replacements for 40W incandescent on market are not qualified, as some of the LED bulbs with 340 lm are also claimed to be able to replace 40W incandescent bulbs. Some manufacturers believe that due to the directivity of LED luminous flux, in certain situations, for instance in desk lamps with limited illumination radius, LED bulbs rated at 300 or so lm are acceptable replacements for 40W incandescent bulbs.
Currently among the major LED light manufacturers, Philips' and GE's LED replacement for 40W incandescent bulbs meet the 450lm standard, with Philips' 8W Master LED bulb having luminous flux of 470 lm and GE's 8W Model No. 62180 LED bulb reaching 450 lm. Japanese manufacturers such as Toshiba and Sharp also have their products meet the standard due to the existence of Japan Electric Lamp Manufacturers Association's guideline specifications. Osram's cold white LED light bulb reached the 450lm standard but its warm white lights have only 345 lm. Some other major manufacturers such as Samsung, EcoSmart, LEDON, and Feit Electric have also introduced LED replacing bulbs for 40W incandescent bulbs, but their products failed to hit the 450lm standard.
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