Page 31 - Blog Posts v1

The graphs show that the long-pulsed Nd:YAG is, by far, the safest option when considering epidermal damage, for all skin colours. The maximum risk, with this wavelength (1064nm) is only 30% (compared with 100% for the alex/black skin combo).
If we assume that an ‘acceptable’ risk is 50%, or lower, then the diode laser and IPL devices can be safely used for all skin colours up to about 4 – that is up to 33% melanin concentration. However, the graphs appear to indicate that these devices should be used on darker skin colours with great care – i.e. proper skin cooling.
The alexandrite laser fares the worst – due to its wavelength being so highly absorbed by melanin. The 50% safety criteria suggests that those lasers should be used only on paler skin colours, unless plenty of cooling is also used.
Conclusions
The risk graphs only serve to indicate where the risk of epidermal damage is greater. Like all risks, these can be mitigated - with proper skin surface cooling. If sufficient cooling is applied BEFORE the light energy is fired, then the risk of epidermal damage can be significantly reduced. Skin cooling AFTER the application is also necessary since my calculations reveal that more than 90% of the applied energy is not used to cook the hairs!
In summary, when trying to remove hair or blood vessels with light energy, we run the very real risk of damaging the epidermis, depending on how much melanin it contains. However, this can be properly managed if good skin cooling is also applied.
Hope this makes sense, Mike.
Mike’s Blog Posts 31