tingling, itching, burning, or prickly feeling. Onset may occur immediately to four hours after exposure and may last 2–30 hours, without damage. First aid measures are included with the label information. The World Health Organization (WHO) and Food and Agriculture Organization (FAO) joint meeting on pesticide residues has determined that the acceptable daily intake for λ-cyhalothrin is 0-0.02 mg/kg bodyweight per day. The Codex Alimentarius database maintained by the FAO lists the maximum residue limits for cyhalothrin isomers in various food products. Effects on the environment While cyhalothrin is inherently highly toxic to many fish and aquatic invertebrate species, binding to soil and sediment reduces exposure and lessens the risk to fish: field studies found no significant adverse effects: according to the WHO expert committee, "The concentrations of cyhalothrin and lambda-cyhalothrin that are likely to arise in water from normal agricultural application will be low. Since the compound is rapidly adsorbed and degraded under natural conditions, there will not be any practical problems concerning the accumulation of residues or the toxicity of cyhalothrin or lambda-cyhalothrin in aquatic species. Honeybees, Apis mellifera have been shown to be particularly sensitive to λ-cyhalothrin, with fatal doses as small as 0.04 micrograms per bee. However, field studies found few effects. Nevertheless, due to this sensitivity and pollinator decline, all pyrethroids are recommended to be applied at night to avoid typical pollinating hours, and not to be used in dust form. In laboratory studies, alkaline water (pH of 9) degraded λ-cyhalothrin with an approximate half-life of 7 days, although at neutral and acidic pHs, degradation did not occur. Sunlight accelerates degradation in water and soil. Its half-life on plant surfaces is 5 days and it has a low potential to contaminate ground water due to its low water solubility and high potential to bind to soil organic matter. The LD50 is 56 mg/kg (rats, oral) and its effects on the environment have been summarized in many publications. Resistance management As with many pesticides, species have the ability to evolve and develop resistance to pyrethroids. This potential can be mitigated by careful management. Reports of individual pest species becoming resistant to λ-cyhalothrin are monitored by manufacturers, regulatory bodies such as the EPA and the Insecticide Resistance Action Committee (IRAC). In some cases, the risks of resistance developing can be reduced by using a mixture of two or more insecticides which each have activity on relevant pests