1. CAN FOOD CROPS BE GROWN SAFELY IN PLASTIC
CONTAINERS?
By Prof. Dr. Willem VAN COTTHEM
Botany Department
University of Ghent (Belgium)
http://desertification.wordpress.com/2013/02/23/can-
food-crops-be-grown-safely-in-plastic-containers-
willem-van-cotthem/
Some gardeners fear that growing vegetables or herbs
in plastic containers (bottles, pots, buckets and the like)
could be dangerous because of the supposed leaching of
Bisphenol A (BPA), and the "possibility" that this leached
BPA could be absorbed by the plants, rendering them
"toxic" for human consumption.
Concerning the possible danger of using plastic
containers for plant production, one should be looking
for irrefutable scientific proof of the presence of BPA in
food crops grown in such containers. The fact is that, to
the best of my knowledge, no such evidence exists in
scientific literature.
Some publications on BPA
(1) What is BPA, and what are the concerns about BPA?
Answer from Katherine Zeratsky, R.D., L.D.
http://www.mayoclinic.com/health/bpa/AN01955

2. “BPA stands for bisphenol A. BPA is an industrial
chemical that has been used to make certain plastics and
resins since the 1960s.
In particular, BPA is found in polycarbonate plastics and
epoxy resins. Polycarbonate plastics are often used in
containers that store food and beverages, such as water
bottles, and baby bottles and cups. They may also be
used in toys and other consumer goods.
………………….
Some research has shown that BPA can seep into food or
beverages from containers that are made with BPA or
into your body when you handle products made with
BPA. BPA remains controversial, and research studies
are continuing. The American Chemistry Council, an
association that represents plastics manufacturers,
contends that BPA poses no risk to human health.
But the National Toxicology Program at the Department
of Health and Human Services says it has "some
concern" about the possible health effects of BPA on the
brain, behavior and prostate gland of fetuses, infants and
children. This level of concern is midway on its five-level
scale, which ranges from serious to negligible. The Food
and Drug Administration now shares this level of
concern and is taking steps to reduce human exposure to
BPA in the food supply by finding alternatives to BPA in
food containers.”

3. (2) Plastic Bottles Release Potentially Harmful
Chemicals (Bisphenol A) After Contact With Hot Liquids
http://www.sciencedaily.com/releases/2008/01/0801300
92108.htm
“Feb. 4, 2008 — When it comes to Bisphenol A (BPA)
exposure from polycarbonate plastic bottles, it's not
whether the container is new or old but the liquid's
temperature that has the most impact on how much
BPA is released, according to University of Cincinnati
(UC) scientists.
Scott Belcher, PhD, and his team found when the same
new and used polycarbonate drinking bottles were
exposed to boiling hot water, BPA, an environmental
estrogen, was released 55 times more rapidly than
before exposure to hot water.
"…………….. BPA can migrate from various polycarbonate
plastics," explains Belcher…………but we wanted to know
if 'normal' use caused increased release from something
that we all use, and to identify what was the most
important factor that impacts release."
…………………………….
The chemical--which is widely used in products such as
re-usable water bottles, food can linings, water pipes
and dental sealants--has been shown to affect
reproduction and brain development in animal studies.

4. "There is a large body of scientific evidence
demonstrating the harmful effects of very small
amounts of BPA in laboratory and animal studies, but
little clinical evidence related to humans," explains
Belcher. "There is a very strong suspicion in the scientific
community, however, that this chemical has harmful
effects on humans."
…………………….
The UC researchers found that the amount of BPA
released from new and used polycarbonate drinking
bottles was the same -- both in quantity and speed of
release -- into cool or temperate water. However,
drastically higher levels of BPA were released once the
bottles were briefly exposed to boiling water.
…………………………
Belcher stresses that it is still unclear what level of BPA is
harmful to humans. He urges consumers to think about
how cumulative environmental exposures might harm
their health.
"BPA is just one of many estrogen-like chemicals people
are exposed to, and scientists are still trying to figure out
how these endocrine disruptors--including natural phyto-
estrogens from soy which are often considered healthy--
collectively impact human health," he says. "But a
growing body of scientific evidence suggests it might be
at the cost of your health."

5. (3) Ban BPA? No Chance, Says FDA
How you can protect your family from the chemical
By Emily Main (2012-03)
http://www.prevention.com/health/healthy-
living/breaking-news-fda-will-not-be-banning-
bpa#ixzz2LHddD8Wn
“Much to the chagrin of public health advocates, the
Food and Drug Administration (FDA) has just announced
its decision not to ban the controversial chemical
bisphenol A in baby bottles, canned food, infant formula
cans, or any other use in which the chemical comes into
direct contact with your food.
…………………………….
Best BPA-Free Water Bottles
Here’s what the FDA says about its decision: "The FDA
denied the NRDC petition today because it did not
provide the scientific evidence needed to change current
regulations,” says FDA spokesman Douglas Karas in a
prepared statement. “But this announcement is not a
final safety determination and the FDA continues to
support research examining the safety of BPA." The
agency went on to say that, although they have been
studying the effects of BPA for years, none of their
existing studies show enough evidence to force them to
change their official position on the chemical's safety.

6. That's hardly reassuring to NRDC public health scientists.
"BPA is a toxic chemical that has no place in our food
supply. We believe the FDA made the wrong call," says
Sarah Janssen, senior scientist at NRDC. "The FDA is out-
of-step with scientific and medical research. This
illustrates the need for a major overhaul of how the
government protects us against dangerous chemicals."
(4) F.D.A. Makes It Official: BPA Can’t Be Used in Baby
Bottles and Cups
By SABRINA TAVERNISE
Published: July 17, 2012
http://www.nytimes.com/2012/07/18/science/fda-
bans-bpa-from-baby-bottles-and-sippy-
cups.html?_r=0
“WASHINGTON — The Food and Drug Administration
said Tuesday that baby bottles and children’s drinking
cups could no longer contain bisphenol A, or BPA, an
estrogen-mimicking industrial chemical used in some
plastic bottles and food packaging.
Manufacturers have already stopped using the chemical
in baby bottles and sippy cups, and the F.D.A. said that
its decision was a response to a request by the American
Chemistry Council, the chemical industry’s main trade
association, that rules allowing BPA in those products be
phased out, in part to boost consumer confidence.

7. But the new prohibition does not apply more broadly to
the use of BPA in other containers, said an F.D.A.
spokesman, Steven Immergut. He said the decision did
not amount to a reversal of the agency’s position on the
chemical. The F.D.A. declared BPA safe in 2008, but
began expressing concerns about possible health risks in
2010.
……………………………
BPA has been used since the 1960s to make hard plastic
bottles, cups for toddlers and the linings of food and
beverage cans, including those that hold infant formula
and soda. Until recently, it was used in baby bottles, but
major manufacturers are now making bottles without it.
Plastic items containing BPA are generally marked with
a 7 on the bottom for recycling purposes.
The chemical can leach into food, and a study of over
2,000 people found that more than 90 percent of them
had BPA in their urine. Traces have also been found in
breast milk, the blood of pregnant women and umbilical
cord blood.
……………………………..
The American Chemistry Council said in a statement that
it had asked the F.D.A. to take action because of
confusion, stirred by state legislative and regulatory
actions, about whether baby bottles and cups for
toddlers contain BPA. It said that manufacturers

8. announced years ago that they had stopped using the
chemical in those items.”
------------------------------------------
As some people continue to ask me about the safety of
growing food crops in plastic containers, I submitted the
following question to ResearchGate
https://www.researchgate.net/
If BPA or BPS is leaching from plastic containers filled
with soil, is this toxic substance absorbed by food crops
growing in those containers?
Here are some of the key points from the responses,
along with additional comments from me:
Farid El-Daoushy · Uppsala University - Department of
Physics and Astronomy
“That depends on the organic content of the soils. High
organic content can help screening pollutants and toxic
compounds from water through chelation. This self-
cleaning mechanism of soils with high organic content
can act as natural filters and thereby protect plants
against pollution”.
Willem Van Cotthem · University of Ghent –
Department of Botany
“I would like to know if cultivating food crops in recycled
plastic containers poses a potential danger to public

9. health. If BPA (or BPS) does leach into water (or into the
soil solution inside plastic containers), the question
remains if the leached BPA can be absorbed by roots
growing in the soil within the container. Of course, if the
leaching of BPA (or BPS) into drinks sold in "unsafe”
plastic bottles posed a health risk, the use of those
bottles would have been banned a long time ago. Since
they are still in widespread use, however, one can
conclude that it is safe to use them for food crop
cultivation as well.
Reed Benkendorf · University of Illinois, Urbana-
Champaign School of Integrative Biology
“Is BPA actually leached from any of these plastics? If
so, does humic acid complex it? If not, and BPA is
absorbed by the roots, does it pass through the
Casparian strip in the endodermis cells? Some plants
have a pronounced ability to accumulate toxins in the
cortex but do not transport them further.”
David Dunn · commercial horticulture
“Many crops are grown in plastic containers of various
sorts, especially greenhouse crops with hydroponic and/
or substrate systems, employing more plastics or glass
wool and/or with peat mixtures.
Most crops rely on plastics for delivery of water and
fertilizer to plants and as mentioned above some organic
teas are sometimes used employing highly complex
acids, especially in protected cropping which may cause
leaching from the plastics employed.

10. If there is a problem then it needs to be addressed
quickly to allay fears of the public. “
John Chater · University of California, Riverside
Department of Botany and Plant Sciences
“BPA is a relatively large (and non-polar) molecule
compared to the ions that plants typically are taking up
(K+, N03-, Mg++, … , so I do not think that the plant will
take up the BPA (which has two phenol-groups in the
structure). There is theoretically no way for the soil's
BPA to get into the crop. Remember, all materials need
to pass through the Casparian strip in order to make it
through the root's endodermis and into the
vasculature.”
Willem Van Cotthem · University of Ghent
“It seems difficult, if not impossible, for a large, non-
polar molecule like BPA to be absorbed by root-hair cells
and transported towards all plant parts. If that were the
case, would there not be accumulation somewhere in
the plant body?
An additional question is: Does leaching of BPA occur at
ambient temperatures in the environment (including full
sunshine)? As many food crops (vegetables and herbs)
have been grown for decades already in a wide variety
of plastic containers it seems that if BPA were leaching
and transported into the crops, traces of BPA would
commonly be found in the crops, as well as in the
humans who consume them. No such evidence exists

11. and no such link has been established. I am still
concerned about how the general public seems to draw
a connection between the potential presence of BPA in
plants growing in plastic containers ("safe" and "unsafe"
plastics), and the potential presence of BPA in drinks sold
in plastic bottles.”
Peter Knop · Ticonderoga Arboretum and Botanical
Gardens
“I am surprised that no one has mentioned the
enormous amount of plastic used in row cropping and
the millions of tons of produce grown on such plastic. It
totally dwarfs hydroponics or other container grown
crops. Maybe the term "container" includes these, as for
the bottom of the raised beds the entire root system is
exposed to this plastic mulch. This leads to another
interesting problem: some of these mulches are
biodegradable and their chemicals, like binders, become
part of the soil. Aren’t they dangerous?”
Willem Van Cotthem · University of Ghent
“Indeed, heaps of plastic sheets are used in agri- and
horticulture, even biodegradable ones. If all those
plastics, or only the "unsafe" ones, are leaching
dangerous, toxic elements into the environment, we are
probably "doomed".
Debi Sharma · Indian Institute of Horticultural Research
“If leaching of BPA is higher at higher temperatures then
it is a matter of concern especially in tropical
conditions.”

12. Based on the responses I have received to the question I
have put to ResearchGate, no clear proof has been
provided that BPA or BPS is leaching into the soil in
which plants are growing, or that BPA or other toxic
substances are absorbed into those plants.
Is it really dangerous to grow food crops in plastic
containers?
Let us have a look at a recent publication in Science
Daily(2013/02):
http://www.sciencedaily.com/releases/2013/02/13
0217084541.htm
A scientific analysis of 150 studies in which human
beings have been exposed to "low dosages of BPA"
shows that "in the general population, people's exposure
may be many times too low for BPA to effectively mimic
estrogen in the human body."
The analysis of 130 toxicity studies of BPA showed:
"………………….that a small fraction of the "low doses"
used in these studies are within the range of human
exposures, with the vast majority being at least 10 to
thousands of times higher than what humans are
exposed to daily. In addition, the range of
concentrations spans from upwards of 10 grams per
kilogram of weight per day down to 100 picograms per

13. kilogram of weight per day (a picogram is one millionth
of a gram).
"Unfortunately, the low dose moniker has been used by
some to promote the importance of selected toxicity
studies, for example, in arguments to ban BPA," said
Teeguarden. "For BPA and all chemicals, we need more
accurate language to present these findings so the
public and scientists in other disciplines can understand
how human exposures compare to exposures in
laboratory studies reporting toxicity."
Although I am more convinced than ever that it is safe
to grow plants in plastic containers, I would still like to
obtain conclusive answers to the following two
questions:
(1) Is BPA (or BPS), within ambient environmental
temperatures (even in sunshine), really leaching in any
notable concentrations from the plastic bottles, pots or
buckets in which we grow our fresh food?
(2) If so, are plants absorbing it in such concentrations
that eating them poses a danger to public health?
Expecting that one day we will be able to find the

14. answers based on long-term, independent scientific
studies, I continue for now to promote my bottle tower
method (http://youtu.be/JtbOREs2kIo) as a
particularly effective way to combat malnutrition,
hunger and poverty in developing countries.
As long as all the specialists-experts of the world
scrutinize every day the production and sales of food
and drinks in plastic containers, as long as they allow
millions of people to eat and drink from plastic
containers, I will continue to believe that the fresh food
we produce in the same containers constitutes no direct
danger for public health.