Are Charcoal Briquettes Toxic? The Health Risks Explained

Charcoal briquettes release a mix of toxic compounds when they burn, including carbon monoxide, fine particulate matter, and cancer-linked chemicals called polycyclic aromatic hydrocarbons (PAHs). The risks range from acute carbon monoxide poisoning in enclosed spaces to long-term concerns about airborne pollutants and contaminants that settle into grilled food. How dangerous they are depends heavily on where and how often you use them, but the combustion chemistry is genuinely concerning, and briquettes consistently perform worse than both lump charcoal and gas grills in emissions studies.

Carbon Monoxide Is the Most Immediate Threat

The single deadliest risk from charcoal briquettes is carbon monoxide. CO is colorless and odorless, and briquettes produce a lot of it. A study measuring CO output from various charcoal products found that the average 24-hour CO concentration from all samples reached about 37 parts per million, roughly six times higher than the World Health Organization’s air quality guideline of 6.34 ppm for a 24-hour period.¹ That number comes from an open-air or semi-open measurement context. In a closed room, a garage, or a tent, CO levels climb far higher and far faster.

A systematic review of charcoal-briquette-related deaths found that most fatal cases occurred in enclosed or poorly ventilated spaces, with victims showing blood carboxyhemoglobin levels above 30%, a threshold strongly linked to death.² These fatalities include both accidental poisonings (grilling indoors, using briquettes for heat) and intentional deaths. The review concluded that charcoal briquette combustion in confined spaces remains a significant and preventable cause of CO-related mortality. The practical takeaway is straightforward: never burn briquettes indoors, in a garage with the door partway open, inside a tent, or in any space that does not have full outdoor ventilation.

What Burning Briquettes Release Into the Air

Beyond CO, the smoke from charcoal briquettes carries a cocktail of pollutants. A broad review of charcoal combustion emissions identified CO, CO₂, nitrogen oxides, particulate matter, PAHs, volatile organic compounds (VOCs), and trace metals as components of the smoke plume.³ Briquettes tend to be dirtier than lump charcoal on a per-kilogram basis. One study found briquettes had CO emission factors above 250 grams per kilogram of fuel, VOC emissions above 1.5 grams per kilogram, and total suspended particulate emissions above 7.5 grams per kilogram, all higher than lump charcoal.⁴

The particulate matter is especially striking. During the lighting phase alone, charcoal combustion can push PM10 levels (particles small enough to inhale deeply) to 28 to 104 times above background levels. When fatty foods like salmon or sardines hit the grill, those numbers jump even higher, reaching over 130-fold above background in some cases. Nearly all of that particulate, about 99%, falls into the PM2.5 category, meaning the particles are fine enough to penetrate deep into your lungs.⁵

The PAH story is particularly unfavorable for briquettes. Researchers comparing fuel types found that total PAH concentrations in the air around charcoal briquette grills reached about 21.5 micrograms per cubic meter, compared to undetectable levels around gas grills. The daily PAH exposure for a grill operator working with briquettes, adjusted for toxicity equivalence, was roughly 10,000 times higher than it would be working a gas grill.⁶ Another study calculating incremental lifetime cancer risk found that both lump charcoal and briquette grilling pushed the risk above the threshold generally considered unacceptable, with professional cooks facing the highest calculated exposure.⁷

What Is Actually Inside a Briquette

Part of the reason briquettes emit more pollutants than lump charcoal comes down to what they are made of. Lump charcoal is just carbonized wood. Briquettes, on the other hand, are manufactured products: charcoal fines are bound together with various additives, compressed under pressure, and shaped into uniform blocks. Common binders include starch, flour, lignosulfonate, and sometimes synthetic adhesives like polyvinyl acetate.⁸ Beyond binders, briquettes can also contain fillers, mineral matter, and sometimes coal or coke to extend burn time.

A microscopy study of 74 commercially available charcoal products from seven countries found a range of contaminants in briquettes, including coal, coke, metal fragments, rust, plastics, glues, and synthetic resins. The majority of the products analyzed failed the European quality standard for charcoal briquettes, which allows less than 1% contaminants. Some products contained up to about 27% impurities, and the amount of contaminants correlated with higher particulate matter and CO/CO₂ emissions during burning.⁹

Trace metals are another concern. Briquetted products contain substantially higher concentrations of elements like aluminum, arsenic, copper, nickel, and cadmium than lump charcoal, likely because of the additives and secondary materials used in manufacturing. When briquettes burn and leave ash, the concentrations of these metals increase even further as organic material burns away. A study simulating human digestion found that arsenic and copper in briquette ash were among the most bioaccessible metals, meaning they are readily absorbed by the body. The researchers flagged aluminum and arsenic as the trace elements of greatest health concern from barbecuing.¹⁰

How Grilling Contaminates the Food Itself

The health concern with charcoal grilling is not limited to what you breathe. It also involves what ends up in the food. When meat cooks at high temperatures over an open flame, two classes of potentially harmful compounds form: polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs). PAHs form in two ways. First, fat and juices drip from the meat onto the hot coals and incomplete combustion generates PAH-laden smoke that rises and deposits onto the food.¹¹ Second, direct pyrolysis of the food’s own nutrients at high temperature creates additional PAHs on the food surface.¹²

HCAs are produced by the interaction of creatine, sugars, and amino acids in muscle tissue at high cooking temperatures.¹³ Both PAHs and HCAs have been classified as mutagenic and in some cases carcinogenic. The type of fuel matters here too: one study found PAH concentrations in the air above charcoal-briquette grills were over 250 times higher than above gas grills when grilling meat.⁷ And while high-temperature charcoal grilling raises both PAH and HCA formation in the food, charcoal type and grilling conditions both play a role.¹⁴

What Happens to People Exposed Regularly

For someone who grills a few times a summer, the chronic health risks are relatively small. The exposure duration is short, the setting is outdoors, and the dose is limited. But for people who work around charcoal grills daily, the picture changes. A study of grill workers in Vientiane, Laos, found elevated respiratory symptoms among workers, with contributing factors including indoor grilling, more years of grill work, and exposure to intense smoke.¹⁵

Research on charcoal-grill restaurant workers found significantly more wheezing and shortness of breath compared to control subjects. In one study, roughly half of restaurant workers reported wheezing, compared to none among controls.¹⁶ Work in charcoal production also carries respiratory risk. A study of charcoal workers in Namibia found that those with the highest cumulative dust exposure were roughly twice as likely to report chronic cough and phlegm production, with even higher odds for episodes combining both symptoms.¹⁷

These occupational findings offer a useful lens for the home griller. The effects tracked in workers are dose-dependent: more exposure, more symptoms. A weekend barbecue is orders of magnitude less exposure than eight hours a day beside a grill for years. But the underlying biology is the same. The smoke is irritating and carcinogenic in a dose-dependent way, and standing directly in a thick plume while flipping burgers is not nothing, even outdoors.

Lighter Fluid Adds Its Own Problems

Many people start their briquettes with a squirt of lighter fluid, and the fluid itself brings a separate set of toxicological concerns. Most lighter fluids are composed of C9 to C14 aliphatic hydrocarbons, mainly alkanes and alkenes, with some products containing aromatic constituents up to about 2% of total volume. Safety data sheets classify most of them under a hazard statement meaning they can cause lung damage if swallowed and may be fatal if they enter the airways. Small amounts of volatile C5 and C6 compounds are also typically present as ignition accelerants.¹⁸

In practice, if you let lighter fluid burn off completely before cooking, minimal residue reaches the food. The concern is more about the combustion products added to the smoke plume during the lighting phase, and the environmental load of repeated use. A chimney starter, which uses newspaper or a fire starter cube and convection to ignite charcoal, avoids lighter fluid entirely. Electric starters are another option. Both eliminate the hydrocarbon-solvent component from the equation.

Practical Ways to Reduce Your Exposure

If you grill with briquettes and do not plan to switch to gas, there are evidence-based steps that meaningfully lower the toxic load.

• Use a drip tray: One of the biggest PAH sources is fat dripping onto hot coals and flaring back up as contaminated smoke. A study comparing grilling methods found that the highest PAH levels in chicken came from charcoal grilling without a tray, while the use of a tray or indirect heat substantially lowered contamination.¹⁹
• Marinate your meat: The same study found that certain marinades acted as barriers against PAH absorption, likely because phenolic compounds in marinades scavenge free radicals involved in PAH formation.¹⁹
• Use higher-carbonization charcoal: Research has shown that charcoal prepared using higher carbonization temperatures produces less PAH-laden smoke during grilling. Preheating briquettes before cooking (letting them ash over fully rather than grilling over still-flaming coals) also reduces PAH transfer.²⁰
• Stay upwind: Inhalation exposure depends on your position relative to the smoke plume. Standing directly downwind, breathing smoke for an extended cook, is a very different exposure than standing upwind and stepping in briefly to flip food.
• Skip the lighter fluid: A chimney starter eliminates the hydrocarbon accelerant from the smoke entirely.
• Choose leaner cuts: Fattier foods generate far more particulate matter. The PM spike from grilling sardines or salmon was many times larger than from leaner meats in emissions testing.⁵

None of these steps eliminate the risk entirely. They reduce it. If you grill a handful of times per year, the residual risk after taking these precautions is probably negligible for your long-term health. If you grill weekly or work near a grill daily, the cumulative benefit of combining several of these measures is more meaningful.

What to Do With the Ash

Most people dump briquette ash in the trash or scatter it in the yard without a second thought, but the ash is not inert. When briquettes burn, the organic material combusts and trace metals concentrate in what remains. A study of wood briquette ash found that heavy metal concentrations were significantly higher after combustion than in the original fuel, making some ash samples unsuitable for agricultural use.²¹ Research on household ash disposal in communities relying on solid fuels found that ash dumped on private land or surrounding areas contained extremely elevated heavy metal levels, with some samples showing lead concentrations nearly 50 times higher than national soil quality standards.²²

Charcoal briquette ash is particularly concerning because, as noted earlier, briquettes start with higher concentrations of metals and additives than lump charcoal does. The combustion process concentrates those metals further. Scattering briquette ash in your garden, compost pile, or near a vegetable bed is a poor idea. The safest disposal method is to let ash cool completely, bag it, and put it in household waste. If you use lump hardwood charcoal with no additives, the ash is cleaner and sometimes used as a mild soil amendment, but even then, moderation is wise because of natural metal accumulation during burning.

Briquettes Versus Lump Charcoal Versus Gas

Across nearly every measure that matters for health, briquettes come in last among common grilling fuels. They emit more CO, more VOCs, and more particulate per kilogram than lump charcoal.⁴ They produce higher airborne PAH concentrations than lump charcoal, and dramatically higher concentrations than gas grills.⁶ Their ash carries more trace metals.¹⁰ And many commercial briquettes contain contaminants that fall outside quality standards.⁹

That said, the gap between briquettes and lump charcoal is much smaller than the gap between either solid fuel and gas. Both charcoal types push PAH-related cancer risk above commonly cited safety thresholds for professional grill operators, while gas stays far below.⁷ If you are choosing strictly on health grounds, gas is the clear winner. If you want the flavor profile of charcoal, lump charcoal with no additives is a step up from briquettes. And if you are going to use briquettes regardless, the mitigation steps above, particularly full preheating, drip management, and wind positioning, compress the difference meaningfully.