Only the concentration makes the poison.
Many chemical fertilizers can cause me great distress. Numbness in the fingers and toes, pain of the stomach and intestine, feelings of depression, aches in my joints, lower back pain so bad I can't walk erect, stiffness in my neck that makes it hurt to turn my head and look behind me, sores or sensitive areas on my skin where the contamination sweats out, feeling lethargic or having no energy... even many so called organic foods seem to have chemical contamination. The aches and pains I get from eating foods are the same I get from contact with chemical fertilizers. There is something in chemical fertilizers that is causing it and it seems to be a chemical contaminant, the contamination level drops after many months of curing (I believe due to bacterial digestion of the offending compounds). High grade chemical nutrient (nutrients that have been purified to have very low contamination levels) do not have the same effect. Ammonia may not be the culprit but it is a waste product of human digestion and the body expels a great deal of it in urine and feces.
Vegetables I have grown organically myself have proven that it is not the food but the fertilizer fed to the plant that is the cause.
I'm attempting to grow organically so the bacteria can digest the contamination in the soil and plant well before harvest. I also feel the plant matter for fertilizer will introduce less contamination into the soil than the addition of pure chemical fertilizers.
It's unclear at this point if contamination or hidden hunger is the reason the plant did not do well (still early in my investigation). My experiments with high purity chemicals seem to suggest it is a hidden hunger (perhaps a ultra trace element or elements, much lower required concentrations than micronutrients, that can sometimes be present in agricultural grade chemicals as contaminants).
Perhaps I just had an overly contaminated sample of ammonia (ammonia phosphate and ammonia nitrate) that caused the bad reaction or perhaps it was the ammonia itself. I'm growing out some more plants to try to understand this phenomenon using different chemical inputs (plants just grow very slowly so it takes time). The contamination in the plant material at harvest was much higher with 20 ppm ammonia than it was with 10 ppm ammonia.
I have already proven that a good harvest of the Bruce Banner I'm growing should produce about 1/2 lb from a 5 gallon soil container. I can test the effectiveness of my fertilizer against this number.
I will share this information as I know more.