## 2 Materials and Methods  
### Elastomer Characteristics  
Six distinct silicone (including controls) and two rubber elastomers (with respective controls) formulations, based on performances assessed in a previous study [6], were evaluated in this study. Patented antimicrobial additives (PAAs) were included in each of them. Both of the elastomers and all of the additives are approved by the United States Food and Drug Administration (USFDA) for their use and contact with food. Tables 1 and 2 provide a thorough breakdown of the main components.  
\begin{table}
\begin{tabular}{l c} \hline \hline \multirow{2}{*}{**Main Components**} & **Acronym \\  & **(In Tables)** \\ \hline Silicon rubber (CAS 63394-02-5) 95–99\% & \\ Dicumyl peroxide (CAS 80-43-3) 0.3–1.2\% & CONTROL \\
2.5-Dimethyl-2,5-di(tert-butylperox) hexane (CAS 78-63-7) 0.3–1.2\% & \\ Effectiveness accelerators: & \\ Zinc oxide (CAS 1314-13-2) 1–5\% & VQM105 \\ Magnesium oxide (CAS 1309-48-4) 1–5\% & VQM105 \\ Antimicrobial additive 1\%: & \\ Silver chloride (CAS 7783-90-6) & \\ Silver phosphate glass (CAS 308069-39-8) & \\ Zinc pyrithione (CAS 13463-41-7) & \\ \hline Silicon rubber (CAS 63394-02-5) 95–99\% & \\ Dicumyl peroxide (CAS 80-43-3) 0.3–1.2\% & \\ Antimicrobial additive 1\%: & \\ Silver chloride (CAS 7783-90-6) & VQM500D \\ Silver phosphate glass (CAS 308069-39-8) & \\ Zinc pyrithione (CAS 13463-41-7) & \\ \hline Silicon rubber (CAS 63394-02-5) 95–99\% & \\
2.5-Dimethyl-2,5-di(tert-butylperox) hexane (CAS 78-63-7) 0.3–1.2\% & \\ Antimicrobial additive 1\%: & \\ Silver chloride (CAS 7783-90-6) & VQM500L \\ Zinc pyrithione (CAS 13463-41-7) & \\ \hline Silicon rubber (CAS 63394-02-5) 95–99\% & \\ Dicumyl peroxide (CAS 80-43-3) 0.3–1.2\% & \\ Effectiveness accelerators: & \\ Zinc oxide (CAS 1314-13-2) 1–5\% & \\ Magnesium oxide (CAS 1309-48-4) 1–5\% & VQM561D \\ Antimicrobial additive 1\%: & \\ Silver chloride (CAS 7783-90-6) & \\ Silver phosphate glass (CAS 308069-39-8) & \\ Zinc pyrithione (CAS 13463-41-7) & \\ \hline \hline \end{tabular}
\end{table}
Table 1: The chemical composition of the six silicones tested.  
\begin{table}
\begin{tabular}{l c} \hline \hline
**Main Components** & **Acronym** \\  & **(In Tables)** \\ \hline Ethylene-propylene-diene polymer (CAS 25038-36-2) 35–45\% & \\ Carbon black (CAS 1333-86-4) 25–35\% & \\ Residual oils (CAS 64742-01-4) 5–8\% & \\ Magnesium oxide (CAS 1309-48-4) 1–5\% & OMCONT \\ Zinc oxide (CAS 1314-13-2) 0–2\% & Poly(1,2-dihydro-2,2,4-trimethylquinoline) (CAS 26780-96-1) 0.5–1\% & \\ bis(tert-butyldioxyisopropyl) benzene (CAS 25155-25-3) 1–2\% & \\ Triallyl cyanurate (CAS 101-37-1) 0.5–1\% & \\ \hline Ethylene-propylene-diene polymer (CAS 25038-36-2) 35–45\% & \\ Carbon black (CAS 1333-86-4) 25–35\% & \\ Residual oils (CAS 64742-01-4) 5–8\% & \\ Magnesium oxide (CAS 1309-48-4) 1–5\% & \\ Zinc oxide (CAS 1314-13-2) 0–2\% & \\ Poly(1,2-dihydro-2,2,4-trimethylquinoline) (CAS 26780-96-1) 0.5–1\% & \\ bis(tert-butyldioxyisopropyl) benzene (CAS 25155-25-3) 1–2\% & \\ Triallyl cyanurate (CAS 101-37-1) 0.5–1\% & NBROM \\ Effectiveness accelerators: & \\ Zinc oxide (CAS 1314-13-2) 1–5\% & \\ Magnesium oxide (CAS 1309-48-4) 1–5\% & \\ Antimicrobial additive 1\%: & \\ Silver chloride (CAS 7783-90-6) & \\ Silver phosphate glass (CAS-308069-39-8) & \\ Zinc pyrithione (CAS 13463-41-7) & \\ \hline Ethylene-propylene-diene polymer (CAS 25038-36-2) 40–50\% & \\ Silica gel (CAS 112926-00-8) 15–20\% & \\ Kaolin (CAS 92704-41-1) 2–6\% & \\ Carbon black (CAS 1333-86-4) 25–35\% & \\ Paraffin oil (CAS 97862-82-3) 17–21\% & \\ Magnesium oxide (CAS 1309-48-4) 0–2\% & \\ Polyethylene glycol (CAS 25322-68-3) 1–3\% & CACONT \\ Zinc oxide (CAS 1314-13-2) 1–3\% & \\ Stearic acid (CAS 57-11-4) 0.1–1\% & \\ \(2\),2\({}^{\prime}\)–Dithiobis(benzothiazole) (CAS 120-78-5) 0.1–1\% & \\ Tetramethylthiuram Disulfide (CAS 137-26-8) 0.1–1\% & \\ Rubber Accelerator Zdbc/Bz (CAS 136-23-2) 0.1–1\% & \\ Sulfur (CAS 7704-34-9) 0.1–1\% & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Chemical composition of the four rubbers tested.