I have recently included ammonium chloride solutions in my list of alternative fungal controls for roses and other
ornamentals. These solutions are found in at least four marketed products called Consan Triple Action 20, Consan 20,
Triple Action 20, and TA-20 - all under different manufacturer's labels, but basically developed and licensed by
Parkway Research Corp. of Houston, TX.
The products are primarily used as an algaecide and bactericide in hospitals, nursing homes, offices and schools.
However, within the past few years, ammonium chloride has also been approved as a fungicide in ornamental crops
(and specifically rated for roses) and several ornamental trees. It is currently rated for such diseases as black
spot, powdery and downy mildews, rust, stem gall, brown canker, stem rot, wilt, leaf blight, anthracnose, leaf spot,
heart rot (in palms) and fireblight (in pears and crepe myrtles).
The chemical constituents ("Active Ingredients") are dimethylbenzyl ammonium chloride and dimethyl ethylbenzyl
ammonium chloride in various compositions. The MSDS for ammonium chloride lists an oral LD50 (in lab rats) of
1650 mg/kg - meaning if LD50 were the only determining factor, it would normally have a "Caution" (Level 3)
flagword on the label. Instead, however, there is a "Danger" on the label.
The MSDS also states the following:
EFFECTS OF OVEREXPOSURE INHALATION OF DUST MAY CAUSE IRRITATION TO UPPER RESPIRATORY TRACT. CONTACT WITH SKIN OR EYES
MAY CAUSE IRRITATION. PROLONGED EXPOSURE MAY CAUSE DERMATITIS. INGESTION MAY CAUSE NAUSEA AND VOMITING. INGESTION MAY
CAUSE IRRITATION AND BURNING TO MOUTH AND STOMACH.
The statements about contact with the eyes and skin are understated. In fact, ammonium chlorides are very caustic to
the eyes and corrosive to the skin. Hence, the label on ammonium chloride products will normally carry a "Danger"
flagword. Translated this means: “Corrosive, corneal opacity not reversible within 7 days.”
OSHA's report on ammonium chlorides, as well as the MSDS, indicate there are no "targeted organs" in the human body
where prolonged exposure to the chemical would cause long-term health effects
Ammonium chlorides, however, are toxic to fish. And there is a precautionary statement about using this product where
waterfowl graze, indicating there may be a toxicity accumulation level as yet determined (or extrapolated) for humans.
The good news is ammonium chlorides, when exposed to sunlight, break down rapidly into biodegradable by-products. These
are ammonia and hydrogen chloride.
In my opinion, using ammonium chlorides as an alternative fungal control is a reasonable choice for controlling these
diseases provided they are applied per label directions and appropriate precautions are taken to wear protective clothing
with a face shield and dust mask. That said, I still prefer a less toxic alternative such as whole neem oil or baking soda
with horticultural oil.
By Mark Whitelaw, Kindly Provided by Laura Whitelaw