Acrylic Color Change Due to Substrate?

I was at a reptile show and an acrylic cage vendor told me that acrylic will change color due to coming into contact with substrate for extended periods of time. Has anyone observed this?

Acrylics are subject to degradation over time from various chemicals. Determine the chemical content of the substrate and use this chart to determine the effects, if any. If the color changes it is likely the strength of the material has also been compromised.
http://www.eplastics.com/Plastic/Plastics_Library/Chemical-Resistance-of-Plexiglass-Acrylic

Assuming you are referring to poly(methyl methacrylate), PMMA, it is also subject to discoloration from certain bacteria, especially Cyanobacteria and Archaea.

The Snark said:

Acrylics are subject to degradation over time from various chemicals. Determine the chemical content of the substrate and use this chart to determine the effects, if any. If the color changes it is likely the strength of the material has also been compromised.
http://www.eplastics.com/Plastic/Plastics_Library/Chemical-Resistance-of-Plexiglass-Acrylic

Assuming you are referring to poly(methyl methacrylate), PMMA, it is also subject to discoloration from certain bacteria, especially Cyanobacteria and Archaea.

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Snark..thanks BUT, I wasn't concerned about chemicals per se, like pouring chemical X on it.

I'm wondering if people have observed a color change due to using various substrates, not glacial acetic acid, handy table though. I haven't the faintest idea of what coco fiber is chemically, nor percentages for any given substrate. Lastly, I don't own analytical lab equipment to run samples hahah

The rough rule of thumb is, color change equates to bacteria invading the plastic.

So bacteria from coco fiber causes change in color for this substrate?

viper69 said:

So bacteria from coco fiber causes change in color for this substrate?

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Almost certainly. Acrylic has a micro porous surface. I forget the term they use for that. It presents an ideal habitat for certain bacteria. You've seen how easily certain solvent based chemicals can mark it, as a felt tipped marker. The invading bacteria produce various chemical coloring agents. Cyanobacteria produces blue, another common one makes brown or orange, and one other that comes to mind makes an interesting pinkish color. The chemicals these bacteria produce attack the plastic, usually aided by oxygen which all acrylics are subject to some degradation from, and, usually, permanently stain the plastic's surface.
The coloration cannot be removed because the surface of the plastic itself has been chemically altered.

People often aren't aware of how many different varieties of bacteria are present on virtually all surfaces. A friend of mine did his thesis culturing and identifying bacteria. He was going to culture material from common household surfaces but stopped with just the surfaces around a kitchen sink where he was able to identify over 1200 different bacteria strains.

The Snark said:

Almost certainly. Acrylic has a micro porous surface. I forget the term they use for that. It presents an ideal habitat for certain bacteria. You've seen how easily certain solvent based chemicals can mark it, as a felt tipped marker. The invading bacteria produce various chemical coloring agents. Cyanobacteria produces blue, another common one makes brown or orange, and one other that comes to mind makes an interesting pinkish color. The chemicals these bacteria produce attack the plastic, usually aided by oxygen which all acrylics are subject to some degradation from, and, usually, permanently stain the plastic's surface.
The coloration cannot be removed because the surface of the plastic itself has been chemically altered.

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Yes aware of microporosity haha..and most definitely aware of cyano's oh yes.

Thanks for the coloration confirmation. I had only heard one guy mention it and didn't know this happened. This changes my caging plan/designs considerably.

Sadly that, designing around potential problems like this, seems to be the easiest solution by far. Determining the bacterias and making a hostile barrier is ... well, a little example. We had 4 infant incubators at the hospital that got infected with the brown orange bacteria. I think I had to give the lab around 15 samples to culture before they isolated and identified the particular strain. Then I had to hit up the pharmacy for specific antibiotic which I made into a solution and gave to housekeeping to use on the insides of the incubators. Then I had to write up an infection control protocol and submit it to the IC committee for vetting and incorporating into housekeeping's S.O.P.s for JCAH inspections. FREAKING ROYAL PAIN IN THE TUKUS!

One alternative you could try. Tetracycline is sold by the pound dirt cheap from animal supplies stores (for dairys, fisheries and so on) and covers the majority of potential bacterial infectors. Periodic rinsing with a solution of that might keep things clean.