Author: Aqua Gardening

Plastic In Hydroponics, Is There Any Transfer?

Plastic Hydroponics Tub

Plastics in Aquaponics and Hydroponics

With plastic used throughout hydroponics and aquaponics, there is the possibility of an increase in exposure to dangerous chemicals depending on the type of plastic being used.

At Aqua Gardening, we focus on Plastic type #2 (food safe) for use in Aquaponics, and Plastic types #2 or #5 for Hydroponics. Generally, there is more exposure of Aquaponics systems to UV light and damage from the weather, so these systems must be safe even after they are damaged and scratched. On the other hand, most Hydroponic systems are located indoors or inside greenhouses, so they are generally more protected from the elements and do not get exposed to as much UV. Saying that, all of our NFT channels are made using #2 Food Safe plastic as the majority are exposed to the sun. Many customers favour the savings which come from choosing plastic type #5 over the food grade type #2.


Plastics in Everyday Life

It's known very small bits of plastic get into our food from plastic containers via 'leaching' and 'migration'. Virtually all food packaging materials contain substances that can migrate into the food they come into contact with. The amounts are said to be small, but almost any plastic container can leach trace amounts of plastics under certain conditions.

Heating food increases the amount that is transferred to food, for example in the microwave, or plastic containers in the sun. Migration also increases when plastic come into contact with fatty, salty or acidic foods. However, it is unknown how much actually gets into our bodies.

Most of the chemicals known to make the crossing into our bodies are considered to be safe, but this is generally because they haven't been proven to be unsafe. There is little published research on the potential adverse health effects of chemicals that leach from plastic food containers. Two chemicals that have the potential to cause harm to humans are bisphenol A (BPA) and phthalates (pronounced 'thal-ates').


Studies show BPA leaches from cans to the food inside, then is ingested into the bloodstream. It has been shown to be present in more than 90% of the population at a 'detectable' level. BPAs have the ability to disrupt the functions of hormones especially estrogen. BPA plastics are commonly:

  • Used in the linings of canned foods
  • Used for hard, lightweight plastic bottles, commonly polycarbonates

Many studies show high doses of BPA disrupt reproductive development and function of laboratory animals. Levels in humans were believed to be too low to be of concern, but recent research suggests BPA has effects at much lower doses. In addition, the level of BPA in people frequently exceeded the levels shown to have affects in the rodents in the studies.

To reduce your exposure to BPA's, consider:

  • Eating less canned food, and more frozen or fresh food. In addition to avoiding BPA, you'll also get more nutrients from your food - a step toward a healthier diet.
  • Breastfeed your baby or use a powdered formula instead of cans.
  • Avoid bottles and plastic types #3, #6 or #7.


Phthalates are a group of chemical "plasticisers" that are used in a huge variety of consumer products, from PVC pipes to perfume. With millions of tonnes produced annually, phthalates are everywhere. They're even in the indoor dust we breathe. Random sampling shows most people in the U.S. have detectable levels of phthalates in their bodies. Phthalates have been banned in the European Union since 2005. Nine other countries, including Japan, Mexico and Argentina, have also outlawed the chemicals.

Researchers believe most of the phthalates in our bodies come from food, but they don't know exactly how and in what amounts. According to studies phthalates on crops might accumulate in the livestock we eat. Phthalates in plastic packaging could also leach into the food inside.\n\nAvoiding phthalates is tricky, because they're so widespread. Even those using PVC piping in their hydroponic systems as grow channels are likely to have an increased exposure. To reduce your exposure: read on.

Reducing your Exposure

To reduce your exposure to the chemicals in plastic, use these strategies:

  • Paint or cover plastics from the sun.
  • Look for plastic types which are "Food Grade" or HDPE rather than using PVC.
  • Use a paper towel instead of plastic wrap in the microwave.
  • Don't microwave food in plastic containers (put the food on a plate instead).
  • Use safer dishware made from materials like glass or stainless steel.
  • Avoid use of plastic types with 3, 6 or 7 on them. Plastic type 1 (typically used for water and soda bottles) are single use only. Recycle after use.
  • Use tempered glass baby bottles instead of plastic. If you use plastic bottles, don't heat them.
  • Store food in glass or Pyrex containers, rather than plastic.
  • Discard scratched or worn plastic containers.
  • Hand wash plastics to reduce wear and tear.