Re fana ka libotlolo tsa tlhahlobo ea metsi tsa EPA tse pepeneneng le tse entsoeng ka amber bakeng sa ho bokella le ho boloka lisampole tsa metsi. Libotlolo tse bonaletsang tsa EPA li entsoe ka khalase ea C-33 ea borosilicate, ha libotlolo tsa amber EPA li loketse tharollo ea li-photosensitive mme li entsoe ka khalase ea C-50 ea borosilicate.