As of 2023, only three countries still use DDT: India, South Africa, and Zimbabwe. All three use it exclusively for malaria control, spraying it on the interior walls of homes to kill mosquitoes. A handful of other countries keep DDT registered as an emergency option but are not actively spraying it.
Why DDT Is Still in Use at All
DDT was banned for agricultural use worldwide under the 2001 Stockholm Convention on Persistent Organic Pollutants, which classified it as one of 12 chemicals targeted for eventual elimination. But the treaty included a critical exception: countries could continue using DDT for indoor disease vector control when “locally safe, effective, and affordable alternatives are not available.” That exception is what keeps DDT legal in the few places still spraying it.
The method is called indoor residual spraying (IRS). Workers coat the walls and ceilings of homes with a thin layer of DDT, which kills or repels mosquitoes that land on those surfaces. A single application lasts about six months. In areas with seasonal malaria transmission, this can prevent epidemics entirely. In regions where malaria transmission is intense and year-round, it reduces the number of infections and deaths. The World Health Organization promoted DDT-based indoor spraying in 2006 as a frontline tool for malaria control, and it remains on the table where alternatives fall short.
India Dominates Global DDT Use
India is by far the largest producer and consumer of DDT in the world. The country manufactured roughly 4,500 metric tons of DDT per year through the mid-2000s, nearly all of it directed at malaria control. India’s malaria burden is enormous, with transmission occurring across large swaths of the country in both rural and urban areas, and DDT has been a cornerstone of its national malaria program for decades.
India also exports DDT to countries in Africa, either as a raw technical product or in ready-to-use formulations. South Africa and Ethiopia have imported DDT ingredients from both India and China for local formulation and spraying programs.
South Africa and Zimbabwe
South Africa reintroduced DDT for indoor spraying in 2000 after switching to pyrethroid insecticides in the 1990s led to a sharp resurgence in malaria cases. Mosquitoes in the region had developed resistance to pyrethroids, and DDT proved more effective at controlling the specific species driving transmission. The country continues to use DDT in its northern malaria-endemic provinces, particularly KwaZulu-Natal and Limpopo.
Zimbabwe similarly relies on DDT as part of its malaria control strategy, targeting high-transmission areas with indoor spraying. Both countries use DDT alongside other tools like insecticide-treated bed nets, but neither has found a replacement that matches DDT’s combination of effectiveness, duration, and cost in their specific settings.
Who Manufactures DDT
Three countries produce DDT: India, China, and North Korea. India’s production is the largest and is aimed squarely at malaria control. China’s production has historically been much higher in total volume, averaging 4,500 metric tons per year in the early 2000s, but 80 to 90 percent of that went into manufacturing dicofol, a pesticide used against mites and ticks, not into malaria spraying. Another small portion was added to antifouling paints for ships. Only about 4 percent of China’s DDT output was used for malaria control, much of it exported to African countries.
North Korea produces a much smaller quantity, around 160 metric tons per year, and uses most of it in agriculture. This agricultural use violates the Stockholm Convention, which only permits DDT for disease vector control.
Cost Is a Major Factor
One reason DDT persists is price. Alternative insecticides cost 2 to 23 times more per house per six months of protection, according to WHO cost comparisons. For countries protecting millions of homes on tight public health budgets, that gap matters enormously. Pyrethroid prices have been falling as production scales up, making some formulations only slightly more expensive than DDT at lower doses. But in the poorest, highest-burden settings, DDT’s cost advantage remains significant.
Growing Mosquito Resistance
DDT’s effectiveness is declining in some regions. In western Kenya, testing found that the primary malaria-carrying mosquito species had developed high resistance to both DDT and pyrethroids. Mortality rates among mosquitoes exposed to DDT in lab tests ranged from just 50 to 73 percent, well below the threshold needed for effective control. This resistance pattern is not unique to Kenya. It has been documented across parts of sub-Saharan Africa and South Asia, which complicates the argument for continued DDT use in some areas while strengthening it in others where resistance has not yet emerged.
The resistance problem also limits alternatives. Pyrethroids, the most common class of insecticide used in bed nets and spraying programs, face widespread resistance in the same mosquito populations. Organophosphates remain effective in many areas but are more expensive and require more frequent application.
Health Concerns From Indoor Spraying
DDT breaks down slowly. Its main breakdown product, called DDE, accumulates in body fat and can persist in the environment for years. A growing body of evidence links DDT and DDE exposure to breast cancer, diabetes, reduced semen quality, spontaneous abortion, and impaired brain development in children. These associations come largely from studies of populations with high or prolonged exposure.
What remains less clear is the specific risk to people living in homes sprayed twice a year for malaria control. Researchers have noted a significant gap in knowledge about health effects in these communities specifically. The populations most exposed to DDT through indoor spraying are also the ones most vulnerable to malaria, which kills hundreds of thousands of people annually. This tradeoff sits at the center of the ongoing debate: the known, immediate danger of malaria versus the possible long-term health effects of the chemical used to prevent it.
The Path Toward Phaseout
The number of countries using DDT has dropped dramatically. At its peak, DDT was used in dozens of countries for both agriculture and public health. The Stockholm Convention’s 2001 restrictions, combined with international funding for alternative insecticides and integrated pest management, have narrowed active use to just three nations. Several other countries maintain DDT as an emergency reserve, meaning they could resume spraying during a sudden malaria outbreak, but are not currently doing so.
Whether those final three countries can transition away from DDT depends on the availability of affordable, effective replacements and on continued progress against malaria itself. As pyrethroid prices drop and newer insecticide classes enter the market, the economic case for DDT weakens. But in settings where malaria kills tens of thousands of people each year and budgets are razor thin, DDT remains a tool that public health officials are reluctant to abandon without a proven substitute in hand.