Tuesdayâs debate between the Democratic presidential candidates, including Hillary Clinton and Bernie Sanders, will be streamed online for free. CNN, which is hosting the debate, will have it available on CNN.com and on the networkâs mobile apps. Coverage begins at 8:30 p.m.
Paraphenylenediamine (PPD) is a chemical substance that is widely used as a permanent hair dye. It may also been found in textile or fur dyes, dark coloured cosmetics, temporary tattoos, photographic developer and lithography plates, photocopying and printing inks, black rubber, oils, greases and gasoline.
Patch testing using 2% PPD in petrolatum. A +/- reaction (scale measuring PPD sensitivity) to this patch test method usually means that these individuals can use PPD hair dyes without difficulty. A 1+ to 3+ reaction indicates allergic dermatitis will most likely occur with use of hair dyes thus preventing their use.