Myths about A-rated bulbs confirmed or denied

• Myth: Energy saving bulbs give a poor, cold and hard light.
• Myth: It’s not worth switching to A-rated bulbs because the savings are so small.
• Myth: The environmental benefits of energy saving bulbs are outweighed by the negative impact of the mercury in the bulbs.
• Myth: It takes more energy to produce an A-rated bulb than an incandescent.
• Myth: Energy saving bulbs should not be switched on and off too often.
• Myth: Energy saving bulbs do not fit ordinary sockets and stick out from the lamp.
• Myth: There is no knowing whether energy saving bulbs on the recommended list of A-rated bulbs will live up to the quality requirements established by the Trust.
• Myth: Energy saving bulbs can cause skin cancer. 
• Myth: A-rated energy saving bulbs cause stress, concentration difficulties and depression.
• Myth: A-rated energy saving bulbs cause migraine and epilepsy.

Myth: Energy saving bulbs give a poor, cold and hard light
Fact: Under normal use, most of us cannot detect any colour difference in the light from a conventional incandescent bulb and an A-rated bulb with the Energy Saving Label.

Fact: If you want a warm light the colour temperature should be around 2,700 K, thus relatively low. You can see the colour temperatures of individual bulbs on the Trust’s overview of recommended A-rated bulbs.

Fact: You could consider retaining conventional bulbs or possibly halogen spots in places where you require particularly good colour reproduction.

Facts about colour quality
A bulb’s ability to reproduce colour is based on the CRI (colour rendering index) scale of 0-100, where the capacity of daylight to reproduce colour is rated at 100. An incandescent bulb’s colour rendering ability, which is 99, is very close to daylight. An ordinary A-rated bulb's CRI value is 80-85. You can see the CRI value for individual A-rated bulbs on the Trust’s overview of recommended A-rated bulbs.

Energy saving bulbs (CFLs) are available with tri-phosphor and 5-phosphor coatings. Tri-phosphor CFLs have 3 primary colours, but 5-phosphor bulbs have more. This makes 5-phosphor CFLs somewhat better in colour terms, and therefore these typically have a CRI value of 90-95. Conversely, they are a little less energy efficient, namely 3 times more energy efficient than incandescent bulbs. Tri-phosphor CFLs are 4-5 times more efficient than incandescent bulbs. 

Spectral curve for tri-phosphor coating CFLs

Spectral curve for 5-phosphor coating CFLs

Hardly any 5-phosphor coating CFLs are sold in Denmark because producers and suppliers don't consider that there will be any particular demand for them.

Unfortunately, it is not possible to see from the packaging whether a bulb is tri-phosphor or 5-phosphor. Back to top

Myth: It’s not worth switching to A-rated bulbs because the savings are so small
Fact: You save EUR 74 when replacing 1 incandescent light bulb with 1 A-rated energy saving bulb (based over the bulb’s total lifespan and replacing a 60 watt incandescent bulb with a 15 watt A-rated bulb). See calculator (in Danish).

Fact: It never pays to use conventional bulbs – even if you’re given them for free. Back to top

Myth:  The environmental benefits of energy saving bulbs are outweighed by the negative impact of the mercury in the bulbs
Fact: A-rated bulbs contain mercury, which incandescent bulbs do not; but mercury is also discharged into the environment during the production of electricity. To a large extent, Denmark uses coal to generate electricity, and burning coal leads to the discharge of mercury into the atmosphere, even if the smoke is cleaned.

Overall, less mercury is therefore discharged when we use energy saving bulbs because they use so little electricity and last for such a long time. Furthermore, many energy saving bulbs are taken to waste recycling centres where the mercury is processed in an environmentally correct way.

In all cases, choose an A-rated bulb containing the least mercury. You will often find the mercury content listed on the bulb’s packaging. Back to top

Myth: It takes more energy to produce an A-rated bulb than an incandescent
Fact: Yes, but because A-rated bulbs have a longer lifetime it takes less energy to produce them if they are used instead of incandescents.

• Incandescent bulb: Energy used in production = circa 0.29 kWh
• A-rated bulb: Energy used in production = circa 1.7 kWh

A-rated bulbs have a lifetime that is at least 6 times longer than conventional bulbs. So, when you multiply the energy used in the production of an incandescent by 6, the result (namely 1.74 kWh) is a little higher than the figure for an A-rated bulb. Therefore, in the long run, the production of A-rated bulbs is cheaper and more environmentally friendly.

Source: ‘Electric light sources’ published by Denmark’s ‘Lysteknisk Selskab’ in 1993. Back to top

Myth: Energy saving bulbs should not be switched on and off too often
Fact: Energy saving bulbs can be switched on and off just as often as conventional bulbs.

Fact: Some energy saving bulbs on the market have shorter lifetimes if they are switched on and off a lot. However, these are not A-rated energy saving bulbs recommended by the Trust. We lay down specific requirements concerning their ability to be switched on and off a reasonable number of times in relation to the stated lifetime.

Fact about a bulb’s lifetime
An A-rated bulb with the Energy Label burns for between 6,000 and 15,000 hours, and can be switched on and off at least as many times as the number of hours it can be illuminated (lifetime). Look for the lifetime on the bulb’s packaging. If the bulb’s lifetime is 10,000 hours you can therefore switch the bulb on and off between 1 and 10,000 times. Back to top

Myth: Energy saving bulbs do not fit ordinary sockets and stick out from the lamp
Fact: Energy saving bulbs fit the sockets of all lamps produced after 1970.

Fact: On pre-1970 lamps the thread on A-rated bulbs can be too short. In this situation the only solution is to change the fitting.

Fact: A-rated bulbs are made with small and large sockets.

Fact: A-rated bulbs come in all shapes and sizes.

Fact about energy saving bulbs:
In principle, energy saving bulbs are mini-fluorescent lamps. Early incarnations of energy saving bulbs were oblong. Today they come in all shapes and sizes. Back to top

Myth: There is no knowing whether energy saving bulbs on the recommended list of A-rated bulbs will live up to the quality requirements established by the Trust
Fact: We carry out random tests of bulbs featured on the list of recommended A-rated energy saving bulbs. A bulb is deleted from the list and the results are published if it fails to fulfil 1 or more of the requirements. Back to top

Myth: Energy saving bulbs can cause skin cancer
Fact: The claim is greatly exaggerated. You have to be within a few cm of an open (single envelope) CFL for a couple of hours every day for there to be any risk. In practice, this applies to a very small minority of people. Open (single envelope) energy saving bulbs are the ones where you can see the tube - as opposed to bulbs with an extra layer of plastic or glass, which are known as encapsulated (double envelope) CFLs, which are typically traditional, globe and torpedo-shaped. There are no risks associated with buying encapsulated (double envelope) energy saving bulbs.

Fact: If your bare skin is within 2 cm of the bulb, the radiation from an open (single envelope) CFL is equivalent to the level emitted on a sunny summer's day. At a distance of over 30 cm, the radiation is less than being outside on a sunny winter's day. Properly functioning energy saving bulbs do not emit radiation that is not also found in daylight, and the intensity is typically 100-1,000 times less than on a cloudless summer's day.

Fact: The UK's Health protection Agency (HPA) carried out the research, which revealed that open (single envelope) CFLs emit ultraviolet radiation (UV) that can be harmful if you remain within 2 cm or less from the bulb for a couple of hours every day.

Fact: HPA advises consumers not to remove energy saving bulbs from their homes, but to choose encapsulated (double envelope) bulbs for lamps used in close proximity to the skin. For example, this could apply to mechanics or goldsmiths who often work very close to a light source. Open (single envelope) CFLs can be used safely in lamps that are further away from the skin. Radiation is not a problem in this situation.

Fact: People suffering from systemic lupus (erythematosus (Lupus) are very sensitive to light and are allergic to daylight, solariums and ultraviolet light. Consequently, they may need to take special precautions as a result of their illnesstion. Back to top

Myth: A-rated energy saving bulbs cause stress, concentration difficulties and depression
Fact: There are no unequivocal research results documenting that A-rated energy saving bulbs cause stress, concentration difficulties or other malaises. However, it is always important to ensure adequate, good quality lighting in all the places where people work.

Avoid flickering and pulsating lights. You can do this by installing electronic high frequency (HF) ballasts, which are fitted to all energy saving bulbs produced today. Back to top

Myth: Energy saving bulbs cause migraine and epilepsy
Fact: There is no research documenting that energy saving bulbs can trigger migraine or epilepsy.

Early examples of energy saving bulbs on the market pulsated 100 times per second, giving the impression that the light was flickering. This triggered attacks in some migraine and epilepsy sufferers. Today, all energy saving bulbs are fitted with high frequency electronic ballasts with around 60,000 oscillations per second. The combination of high frequency ballasts and the construction of energy saving bulbs means that in practice A-rated bulbs do not flicker at all.

However, some sufferers are claiming that new energy saving bulbs also trigger migraine and epilepsy attacks. But the connection has not been proved. Back to top