Seed Corn

From Cornburning

This question comes up fairly often because the seed corn is out there and it is cheap.

Don't Do It

Even if if you can get the seed corn for free, it isn't worth it. That pink stuff on the outside of the corn kernels is a deadly poison, put there to kill any insects who try to eat the kernels.

There are several issues we try to cover when talking about the troubles with burning seed corn. Basically, they are:

Breathing more toxic dust and absorption through skin while handling
Breathing more toxic products of combustion
Possible contamination of soil
Illegal in some jurisdictions
Eats steel / voids stove warranties

Seed corn is first tested for germination (percentage of sprouting kernels). Corn failing this test is sold at a heavily discounted price and is safe to burn because it is "untreated"

Seed corn is grown and tested to be planted the spring after it is harvested. Seed corn not sold in the spring will not have as high of germination rate by the following spring, and so, therefore is practically worthless to the seed corn distributors. The seed corn companies sell, or even give away in some cases, the old seed corn at greatly reduced prices to farmers who are not concerned about lower yields. Naturally it always attracts a few corn burners too, who want to save a few bucks.

A comparison of treated and un-treated kernels

Seed corn passing germination testing is treated, in which it is coated with a chemical insecticide. Many times this insecticide's active ingredient is Clothianidin (CAS Number 210880-92-5) sold under the trade name Poncho.

The treated seed corn is sold to farmers, but then, if not sold, becomes worthless to the seed corn companies. Some companies then sell the waste product corn to individuals at greatly reduced prices.

Gustafson LLC Corporation submitted adequate toxicology studies to conduct a complete toxicological evaluation of Poncho 600. DPR evaluated the submitted data to ascertain the potential for adverse health effects from exposure. The acute toxicity parameters for Poncho 600 are summarized:

Table 4. Acute Toxicity of Poncho 600 Acute inhalation >2628 mg/m

DPR’s evaluation of the acute toxicity studies indicates that Poncho 600 is low in mammalian toxicity. The precautionary language on the product label adequately identifies the acute toxicity hazards noted in the studies.

Alternately, the red or pink coating could be capstan, a fungicide used on seeds meant for planting. If you buy a bag of cracked corn or other seed treated with capstan, return it to the store. It can kill horses, other mammals and wild birds.

It should also be noted that most tests on the safety of the coatings have been carried out in soil conditions and handling of product, not in the conditions of fire where the chemistry could be very different.

Any burning of carbon based fuels will release toxins, even carbon dioxide is toxic. However these insecticides have long molecular chains which are much more likely carcinogenetic with long term exposure even at low levels.

From the Iowa DNR: Burning Chemically Treated Seed Corn Not Advised

DES MOINES—Concerns about potentially higher home heating costs and the chill in the air have many Iowans again interested in using corn burners for warmth. For many, this is a safe and reliable heat source, but DNR officials caution against burning chemically treated seed corn, which can release toxic chemicals when burned.

“Shelled corn from local farmers and mills is abundant, cheap, safe and makes burning of chemically treated seed corn an unnecessary risk for home use,” said Christine Paulson, an air specialist with the Department of Natural Resources.

She said many corn burner manufacturers also recommend against using chemically treated seed corn that is pink or red in color and contains captan and other pesticides that can emit toxins when burned.

Corn Treated with Clothianidin

“Burning treated seed corn can emit low levels of hydrochloric acids and thiophosgene, also known as mustard gas,” she said. “The highest emissions can occur at start up and shutdown when combustion temperatures are lower, or if the unit is damped down.”

“Burning regular corn can be a clean, excellent source of heat using renewable, Iowa grown energy,” she said. “Just avoid chemically treated seed corn, often provided free by companies trying to get rid of old supplies.”

For more information contact Christine Paulson at 515-242-5154.

From the Field Crop Advisory Team Alert: Can I burn treated seed in my corn stove? I get this question a lot! The Poncho label indicates that you should not stand in the smoke while burning treated seed, but it does not specifically mention corn stoves. EPA recommends not to burn treated seed in a corn stove for home heating. http://www.ipm.msu.edu/CAT05_fld/FC05-12-05.htm

A question exists as to the fly ash. Because it and heavier particles drop to the ground you will be likely contaminating the soil also. The soil your kids or grandkids might play in. Bad news all around. It is also possible mercury and other heavy metals could be some of the by-products of burning treated seed corn. If this is the case, you would be liable to the EPA for cleanup bill for soil contamination.

In the states of Nebraska and Minnesota it is against the law to burn treated corn. In Minnesota legislation is being drafted that you are prohibited from offerring treated seed corn for sale for burning in corn burning stoves and that [MPCA has taken action] to regulate the sale of treated seed corn for corn burning stoves?

Some states are just catching up with this practice and beginning to prohibit sales of treated seed corn to consumers for use in corn stoves and furnaces. Minnesota is leading the way on what is certain to be on the agenda in many states as corn stoves and furnaces grow in popularity. With oil prices pushing above $90.00, Heating Oil and Propane are sure to join Electricity as very expensive energy options that corn and wood pellets offer significant savings to consumers looking for alternative energy sources. However, the savings from treated seed corn may come with hidden costs far greater than anyone imagines. For me, keeping family warm and safe is worth some added costs. When it comes to savings from treated seed corn, Just Don't Do It.

Some of the insecticides will leave a gummy substance on the heat exchanger and exhaust. After time this gunk will need to be cleaned from your stove, exposing you to potentially concentrated levels of chemical waste.

Corn sellers report people have been burning this stuff for 4 and 5 years. All have said no ill effects to their stoves but don't handle without rubber gloves, and keep door opening to a bare minimum. They do not address any of the issue of the toxic fumes that could be coming from the stack.

In 2002 LDJ had the process tested by Iowa State University and it was not recommended. When the temperature of the fire stays above 1500 degrees it is enough to burn off the chemicals. If the fire drops below that it will emit harmful gasses and be corrosive to any mild steel. The gentleman at ISU related it as "similar to mustard gas". Very few, if any corn burners on the market sustain those kind of combustion temps constantly, so that is why it is not recommended to burn treated seed corn. It is both an issue of personal safety and product care.

Real bottom line is, understand the risks you are taking not only with your own health but with the health of others and the integrity of your unit. In the 8 years we have been in business the only heat exchanger failures I have seen were products of burning treated seed corn. That is why all manufacturers put a strong disclaimer in their owners manuals - DO NOT BURN SEED CORN. Manufacturers do not put warnings on products for humor's sake. They are there because if they are not followed they will result in product failure, possible injury, or death. I know that sounds extreme, they don't want a failure of their product to cause harm to anyone. Life's too short.

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Burning Seed Corn in Stoves

Kim Grosenheider, Minnesota Pollution Control Agency

Summer is officially over and you may be starting to consider heating options for the approaching notorious Minnesota winter. One option you may be considering is burning seed corn or other grains in indoor heating units (like corn-burning stoves, etc.).

Initially, it may seem like a cheap alternative fuel, but burning waste seed corn in a corn-burning stove is not allowed in Minnesota. Pesticides (Captan, Poncho, Lorsban, Maxim XL, etc.) are commonly present on seed corn. When pesticide-treated seed corn is heated (especially at low temperatures, such as in startup and shutdown operations) it can give off harmful fumes such as hydrochloric acid and thiophosgene (mustard) gas.

Seed corn becomes solid waste once it is no longer used for its intended purpose: planting corn. To burn seed corn would be burning solid waste. This would make the corn burning stove a solid waste combustor. Small onsite waste combustor units are banned in Minnesota (Minn. Rule 7011.1220). Therefore burning seed corn in these units is illegal. The Minnesota Department of Agriculture and Department of Health will be releasing more information on this topic soon. Contact the Small Business Environmental Assistance Program to receive a copy of this information once it becomes available. —

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