Roundup Ultra is a non-selective, post-emergent herbicide designed for broad-spectrum control of annual and perennial weeds. It functions by being absorbed through the foliage and translocated throughout the plant system, killing weeds down to the root. The product is used for clearing unwanted vegetation in agricultural, industrial, and residential settings, leading to significant utility and considerable public discussion regarding its safety.
The Science Behind Weed Control
The active ingredient in Roundup Ultra is glyphosate. This chemical functions by disrupting a fundamental metabolic process found only in plants, fungi, and certain microorganisms. Glyphosate targets and inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS).
The EPSPS enzyme is a component of the shikimate pathway, a biochemical route solely responsible for synthesizing the aromatic amino acids phenylalanine, tyrosine, and tryptophan in plants. When glyphosate blocks this enzyme, the plant cannot produce these necessary building blocks for proteins. The resulting metabolic shutdown leads to the plant’s death. Since the shikimate pathway is absent in animals, the scientific rationale for the compound’s low acute toxicity to mammals has historically been emphasized.
Safe Handling and Application Guidelines
Users must adhere to specific protocols to minimize exposure. Personal protective equipment (PPE) should be worn, including long-sleeved shirts, long pants, socks, shoes, and chemical-resistant gloves to prevent skin contact. Eye protection, such as safety goggles, is also recommended to shield against spray mist or splashes.
Application should be precise, targeting only unwanted vegetation. Use coarse sprays and flat fan nozzles to prevent the herbicide from atomizing into a fine mist. Avoiding application during windy conditions prevents spray drift, which can damage non-target plants or neighboring landscaping. Solutions should only be mixed and stored in stainless steel, plastic, or fiberglass containers, and never in galvanized or unlined mild steel, as this can create a highly flammable hydrogen gas. Dispose of empty containers and unused product according to local regulations.
Public Health and Environmental Debates
The health and environmental impact of the herbicide has been the subject of ongoing, intense public and regulatory scrutiny. The World Health Organization’s International Agency for Research on Cancer (IARC) classified glyphosate as “probably carcinogenic to humans” in 2015, specifically citing a limited association with non-Hodgkin lymphoma (NHL). Conversely, regulatory bodies such as the U.S. Environmental Protection Agency (EPA) and the European Food Safety Authority (EFSA) have consistently concluded that glyphosate is not likely to pose a cancer risk to humans when used according to label instructions.
This difference in classification has fueled extensive legal action, with tens of thousands of lawsuits filed alleging that the manufacturer failed to warn users about the potential link between the herbicide and NHL. Juries in several high-profile cases have returned verdicts in favor of the plaintiffs, leading the manufacturer to set aside billions of dollars for settlements and future claims. Legal arguments often center on the claim that the formulated product, which includes “inert” ingredients like surfactants, may present a higher hazard than the active ingredient alone.
Environmental concerns primarily involve the contamination of non-target ecosystems. Although the product is generally considered to bind tightly to soil particles, preventing extensive leaching, surface runoff and spray drift can carry the chemical into water bodies. Measurable quantities of the active ingredient and its primary degradation product, Aminomethylphosphonic acid (AMPA), have been detected in surface waters.
The herbicide is classified as toxic to aquatic organisms, with potential long-lasting effects. Non-target species, particularly amphibians, have shown sensitivity due to their reliance on both aquatic and terrestrial environments. While some studies suggest the environmental impact is minimal compared to older herbicides, the widespread use and persistence of the compound and its metabolites in the environment remain a serious point of contention for environmental health advocates.