There are three big categories of synthetic chemicals that are used along the dairy production chain: fertilizer, pesticides, and drugs.
Synthetic fertilizers are manufactured nutrients that are a result of chemical processing. They are typically sourced from petrochemical products. While they can include a variety of macro and micronutrients, the three main building blocks are nitrogen, phosphorus, and potassium. In dairy, fertilizer is primarily used in the production of feed such as corn and soy. The overuse of synthetic fertilizers is widespread, and has led to pollution of our waterways, biodiversity loss, soil degradation, and contributed to climate change.
Synthetic pesticides are chemicals that are used for destroying pests. The most common categories of pesticides are insecticides (used for killing insects), herbicides (used for killing plants), fungicides (used for killing fungus), and rodenticides (used for killing rodents). In conventional dairy, pesticides are commonly used in the production, transportation, and storage of feed. In the field, pesticides have contributed to widespread environmental catastrophes, including biodiversity loss, pollinator population collapse, soil health decline, and water contamination, to name a few. When pesticides are used in the production of cattle feed, their residues are consumed by the cows, and can be excreted into milk, resulting in pesticide residues in conventional dairy.
Drug use in conventional dairy production is common. Dairy cattle are often treated with antiseptics, bactericides, and fungicides for skin or hoof infections, cuts, and abrasions; steroid anabolic growth promoters and peptide production enhancers; antiparasite drugs; antibiotics to control diseases and to promote growth; and reproductive aids to increase fertility. Unfortunately, some of these drugs can have dangerous impacts on human health, such as the proliferation of antibiotic-resistant bacteria. Additionally, there is a risk for drug transfer into milk, resulting in drug residues at the grocery-store level in conventional dairy.