im try to use uvc tube to this for sterilize but theres a plastic cover if uvc cant go through cut the part of cover so i can ues safely

if can is it still harmful to me when i use?

It is impossible to tell by looking if the particular plastic is opaque to any particular part of the UV spectrum.
Also, if the UV is the right wavelength and enough power to sterilise anything, then it's likely to damage you.