2,4-Dinitrophenol (2,4-DNP, or DNP) is an organic compound with the molecular formula C6H4N2O5. It inhibits efficient energy (ATP) production in cells with mitochondria. DNP uncouples oxidative phosphorylation by carrying protons across the mitochondrial membrane, leading to rapid energy consumption without ATP generation.
2,4-DNP is a yellow solid with no known smell. It dissolves slightly in water and does not easily evaporate when present in water or soil as a pollutant.
What is 2,4-dinitrophenol used for?
2,4-DNP is used in manufacturing dyes and wood preservatives, as a pesticide, and as an indicator for detecting potassium and ammonium ions. It is also used in photographic developers and explosives. In the 1930s, 2,4-DNP was used as a weight-loss drug, but this was banned in 1938 due to safety concerns.
2,4-DNP is used in manufacturing dyes.
Sources and Routes of Exposure
Sources of Exposure
People may be exposed to 2,4-DNP by:
Breathing contaminated air
Drinking contaminated water
Eating contaminated food
Contact with contaminated soil
2,4-DNP is found in industrial wastewater. Groundwater near factories that used DNP has shown contamination levels of up to 30.6 mg/L. Airborne exposure is a concern in some workplaces. People living near hazardous waste sites may be exposed by breathing contaminated air or through skin contact with polluted soil. Workers in industries manufacturing or using DNP, as well as those involved in waste incineration or cleanup, are at risk.
Routes of Exposure
Inhalation
Ingestion
Dermal and eye contact
Health Effects
Acute Effects
Increased basal metabolic rate
Nausea, vomiting, dizziness
Sweating, headache
Weight loss
DNP is considered highly toxic, as short-term animal studies show severe effects.
Chronic Effects
Long-term exposure in humans and animals has led to:
Cataract formation
Skin lesions
Effects on bone marrow, central nervous system (CNS), and cardiovascular system
The Reference Dose (RfD) for 2,4-DNP is 0.002 mg/kg/day, based on cataract formation in humans. The EPA has not established a Reference Concentration (RfC) for 2,4-DNP.
Reproductive/Developmental Effects
Case reports of women taking 2,4-dinitrophenol orally for weight loss suggest that it may affect the female reproductive system, but the limited information is inconclusive.
One study reported an increased incidence of stillborn animals and increased pup mortality in the offspring of animals exposed to 2,4-dintrophenol by gavage.
Cancer Risk
No data is available on the carcinogenic effects of 2,4-DNP in humans.
Studies on mice found no evidence of tumour development.
The EPA has not classified 2,4-DNP for carcinogenicity.
Safety Measures
First Aid Measures
Eye Contact: Flush with water for 15 minutes and seek medical attention.
Skin Contact: Wash with water and soap for 15 minutes, remove contaminated clothing, and seek medical attention.
Serious Skin Contact: Use disinfectant soap, apply antibacterial cream, and get medical help.
Inhalation: Move to fresh air; if breathing is difficult, administer oxygen and seek medical attention.
Serious Inhalation: Evacuate to a safe area, loosen tight clothing, and administer oxygen if needed.
Warning: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious, or corrosive. Seek immediate medical attention.
Ingestion: Do not induce vomiting; seek immediate medical attention.
Fire Information
Highly flammable in the presence of open flames, sparks, heat, and combustible materials.
Explosion risk when exposed to heat, friction, or shock.
Forms explosive salts when mixed with alkali or ammonia.
Firefighting measures:
Use dry chemical powder for small fires.
Use water spray or fog for large fires.
Cool containers with water jets to prevent explosions.
Exposure Control & Personal Protection
Engineering Controls
Use explosion-proof electrical (ventilating, lighting, and material handling) equipment.
Ensure local exhaust ventilation to keep exposure levels low.
Personal Protective Equipment (PPE)
For handling DNP:
Splash goggles;
Lab coat;
Dust respirator (be sure to use an approved/certified respirator or equivalent);
Gloves;
Suggested protective clothing might not be sufficient; consult a specialist before handling this product.
For large spills:
Splash goggles;
Full suit;
Dust respirator;
Boots;
Gloves;
A self-contained breathing apparatus should be used to avoid inhalation of the product.
Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.
Regulation
United States
No workplace exposure limited have been set for DNP
EPA: The United States Environmental Protection Agency lists DNP as a hazardous air pollutant under the Clean Air Act. EPA recommends that the amount present in bodies of water, such as lakes and rivers, should not be more than 0.07 mg/L in water used for swimming or where water might possibly be swallowed. No more than 0.765 mg/L should be present in water where people catch fish to eat, but there is no swimming. EPA requires industry to report releases or spills of 10 pounds or more of DNP. EPA has designated DNP as a hazardous substance, and intends to cancel, restrict, or require reregistration of pesticide products containing dinitrophenols. DNP is also listed as a waste constituent, and specific regulations regarding its disposal are in effect.
As scientists who evolve with technology we treat innovation as a way of life, a life we dedicate to improvement and advancement of Safety, Health and Environment.
