Compact fluorescent lamps come under scrutiny for energy saving andsafety performance - CHOICE # 391

Are compact fluorescent lamps (CFLs) truly as energy saving and safe as their claims?

In probably the most comprehensive test the Consumer Council has ever undertaken since the inception of CFLs on the market in recent years, the Council has evaluated the performance and safety of 20 models of the product.

In the performance test, which was conducted in collaboration with the Electrical and Mechanical Services Department (EMSD), the samples were put through a series of tests to assess them on:

• accuracy of rated wattage ranging from 7W to 25W;
• lumen maintenance (drop in illumination between the initial 100 hours and 2000 hours of usage); and
• luminous efficacy (the better the efficacy the more energy saving for the same amount of lumen output).

On rated wattage accuracy, the results indicated that most samples fell short of their claimed values of wattage.

The discrepancy between the actual wattage and the claimed wattage reached 15% or above in 5 samples - 1 claimed 11 watts but were measured with only 4.4 watts, a shortfall of 60%.

A CFL with an actual wattage lower than the claimed wattage may not generate the level of illumination expected of the lamp.

Price-conscious consumers should take note of such discrepancy but bearing in mind also that lamps with higher wattage are usually priced higher.

On lumen output, a selling point of CFLs is that their lower wattage is comparable with the higher wattage of conventional incandescent light bulbs.

The test, however, found considerable discrepancy as, for instance, in the case of 2 CFL samples both bearing the identical claim of 9W equivalent to 45W incandescent lamp.

But the results showed that 1 sample had a measured lumen output of 511 lumen at 8.2W compared with the other of only 153 lumen at 4.8W, a difference in lumen output of 2.3 times.

Lumen output of CFLs will reduce after usage for a period of time - a drop of an average 5.2% to 19.3% after usage for between 100 and 2,000 hours. If the reduction in lumen output is significant, this may necessitate the consumers to replace the lamp for better lighting even though it is still serviceable.

On luminous efficacy, which largely determines the energy saving of CFLs, the samples were found to vary from the lowest 31.9 lm/W to more than double 68.6 lm/W.

In addition to the performance test, the Council conducted a safety test on the product including protection against electric shock, interchangeability and marking.

All but 4 samples passed all the safety tests in compliance with the IEC 60968 Standard. The 4 samples in question failed in one or two of the relatively minor safety requirements for:

• missing wattage and current marking;
• the dimension of the lamp cap was not aligned with the standard resulting potentially in bad connection of the contacts.
• In another sample, the edge of the metal cap might still be touchable when screwed into the socket.

The test could establish no direct correlation between the quality and the price.

The majority (16) of the samples were priced between $25 and $45. The top 3 performers scoring full marks on a scale of 5 points based on overall rating of performance (75%) and safety (25%), were within this price bracket.

The attention of CFL users was drawn to the importance of proper disposal of CFLs since most CFLs contain mercury and heavy metal which need to be handled with due care to avoid causing potential health hazard and serious environmental pollution.

In this connection, the lighting industry has launched the Fluorescent Lamp Recycling Programme, with the support of the Environmental Protection Department, in 2008. Consumers are strongly advised to pack the old CFL well before discarding them into designated collection bins for recycling purposes.