ultraviolet light

This is because the in-band response does not match the ideal UV-A response function well.

In this way, eumelanin appears to protect the skin from the oxidation that UV-A and UV-B can cause.

National Laboratory have shown that UV-A can damage DNA in both bacteria and human cells via mechanisms quite different from those of shorter-wavelength UV (SN: 11/30/85, p.

But research at Argonne (Ill.) National Laboratory is now demonstrating clearly identifiable damage to DNA--both in bacteria and in human cells--irradiated with the longer wavelengths known as UV-A. Moreover, this research is showing that the mechanisms causing UV-A's damage is quite different from what occurs with exposure to shorter UV wavelengths.

Two new high-performance uv absorbers: Cyasorb UV-l164 hydroxytriazine with low volatility and good solubility in most polymers provides strong absorbency in both the UV-A and UV-B regions; and Cyasorb UV-3638 benzoxazinone with very strong absorbency in the UV-A and UV-B regions is extremely low in volatility and does not contribute color to the matrix.