Organic Gardening – Understanding Labeling

By Mark Countryman, CEA— Horticulture TCE Fort Bend County

 

Organic gardening is an environmentally conscious method of controlling many landscape pests. The products used are naturally occurring. However, there are still human toxicities involved in this method of pest control. Just because it is environmentally conscious does not mean that it is non-toxic to humans.

 

People need to understand LD50s. This is the lethal dose, usually taken orally, of milligrams to kilograms to body weight expressed as mg/Kg to kill 50% of the test population. (siri.uvm.edu/ppt/whmis2/sld031.htm) . Keep in mind that the lower the number the more toxic the chemical is to humans. For example, an LD50 of 10 is 100 more toxic of a chemical with an LD50 of 1000.

 

Another concept to understand is the term organic. In basic terms, organic simply means that a carbon compound is involved. Anything that was once alive has carbon in it and is therefore organic. Some items, such as oil, have carbon and are therefore organic, but you would not go and pour a can of oil on your garden soils.

 

The point is to read and follow label directions thoroughly. Organics have potential of danger just like many of the so-called synthetic or inorganic chemicals. What you need to do is look at the label. On every label should be printed; Caution, Warning or Danger depending on the health hazard potential in relation to humans.

 

· Category 1 Danger-Poison with skull and crossbones has an LD50 of 1-50.

· Category II is Warning with an LD50 of 50-500

· Category III is Caution the LD50 is 500-5000

· Category IV also Caution LD50 greater than 5000

· Every label should also say "Keep out of reach of Children"

 

Here are some examples on some commonly used "organic chemicals” used around household landscapes and their corresponding labeling.

 

Caution III & IV: fish emulsion, pure vinegar, dormant oil spray, permethrins, thuricide, Bt, potassium bicarbonate, copper hydroxide, calcium chloride, neem oil

 

Warning: d-limonene, pyrethrins, zinc sulphate

 

Other everyday products:

· Caffiene LD50 3-20 - Danger-Poison

· Pure form acetamenophen LD50 338 - Caution

· Alcohol LD50 10—Danger-Poison

 

Finally, again, always read and follow label directions.