Radiocarbon (14C) methodology was used to investigate the presence of biocarbon in different bio-based disposable packaging products. Packaging waste contributes to a municipal solid waste, which is increasing environmental concerns and resulting in the enhancement of EU regulations that aim to reduce packaging waste. The 14C amount in samples reflects how much of the biocarbon has been used. In this study, the concentration of 14C was determined in commonly used types of disposable packaging, such as cups, plates, straws, cutlery, and baking paper. Samples were made of materials such as paper, wheat bran, sugarcane, and wood. The mean concentration of the 14C isotope, measured by the accelerator mass spectrometry (AMS) technique, is greater than 100 pMC in all tested samples, indicating that the samples are modern. The relatively high 14C concentration values in the waterproof layer of the sample indicate that bioplastic, rather than plastic, was used in its production. The highest 14C isotope concentration values were measured for samples that used the oldest biomass (wood and paper), and the lowest for products from current crops (sugarcane and wheat bran), which is consistent with the trend of changes in 14C concentration in the biosphere. The study also addresses the problem of heterogeneity and representativeness of subsamples.