In this work, four biocides were used for the purpose of growth inhibition of fungi and algae in linear low-density polyethylene (LLDPE) specimens. Benzimidazol-2-yl-carbamicacid methyl ester [carbendazim (CB)], 5-chloro-2-(2,4-dichlorophenoxy)-phenol [triclosan (TS)], and 3-iodo-2-propynyl N-butylcarbamate [iodopropynyl butylcarbamate (IPBC)] were used as antifungal agents, and 2-methylthio-4-ethylamino-6-tert-butylamino-triazin-1,3,5 [terbutryn (TT)] was used as an antialgal agent. Antifungal performance was evaluated by disk diffusion and dry weight techniques, and antialgal activities were carried out by disk diffusion and chlorophyll A methods. Aspergillus niger TISTR 3245 and Chlorella vulgaris TISTR 8580 were used as the testing fungus and alga, respectively. The experimental results suggested that the wettabilities of LLDPE specimens changed with the incorporation of CB, TS, IPBC, and TT biocides without significant changes in chemical structures and mechanical properties of the LLDPE. IPBC with the recommended content of 10,000 ppm was found to give the most satisfactory growth inhibition of A. niger. Antifungal performance evaluations were dependent on the testing methods used, whereas those for antialgal activity were not. The optimum concentration of TT agent for effective killing of C. vulgaris was 750 ppm; this loading could be reduced from 750 to 250 ppm by the addition of either TS or IPBC agent. TS and IPBC could be used as antialgal promoters in the LLDPE specimens. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 371-379, 2013