Sure, no one expects a hot dog to be the healthiest thing at your barbecue. But before you chow down on your frankfurter sandwich — is it a sandwich? a taco? — you might want a little more information about what you’re ingesting. Is a hot dog really worse for you than a fat, juicy burger?

The truth about what’s inside those plastic-y casings isn’t as dark as you may have imagined — though there are certainly some health concerns involved. Most hot dog ingredients fit within a few simple categories. Here’s a rundown of ingredients you might find.

Meat

The type of meat differs depending on the dog, but you’ll typically find beef, pork, chicken, turkey or a combination of these different meats.

You might have noticed that some brands list these meats as “mechanically separated.” Your instinct might be screaming “ew!” — but in the case of pork, chicken and turkey, it’s really not that a big deal. Mechanical separation is the process by which companies use machines to remove meat closer to the bone. That means they need to kill fewer animals to generate the same number of frankfurters.

“From a reduction in food waste standpoint, mechanical separation likely does decrease waste,” Ginger Hultin, spokesperson for the Academy of Nutrition and Dietetics and owner of ChampagneNutrition told The Daily Meal via telephone. “But keep in mind that because of how hot dogs are made, they can be high in fat.” More fatty parts of the animal may be included.

You might be concerned about parts of the animal not typically eaten (bones, organs and byproducts) getting thrown into the mix. By law, mechanical separation cannot involve the grinding, crushing or pulverizing of bones. The bones must remain intact and are removed. Additionally, the U.S. Food Safety and Inspection Service mandates that organs and other byproducts be listed as a separate ingredient on the label. If there’s a kidney in your hot dog, the label has to disclose it.

Mechanical separation of beef has been banned by the USDA since 2004 due to concerns about mad cow disease. Mechanically separated poultry has been deemed safe by the USDA since 1995, and hot dogs cannot be made of more than 20 percent mechanically separated pork.

Salt and preservatives

Salt and other preservatives are added to hot dogs in order to prevent bacteria growth. These are often in the form of nitrites (compounds used to cure meats) and nitrates (salt). You might see these listed as sodium nitrite, sodium erythorbate, lauric arginate or lactate/diacetate. Phosphates are also common; they are salts used to maintain moisture and flavor. Nitrates and nitrites can be caustic to your health when eaten in large quantities, which is why processed meats can be risky for your blood pressure. To avoid these health risks, Hultin advised looking for uncured hot dogs.

Sugars and sugar substitutes

Sugar and other carbohydrates are added to most hot dogs in order to enhance flavor. Dextrose and corn syrup, for example, are sugars, while sorbitol and maltodextrin are substitutes. Both of these substitutes are naturally occurring and safe. Maltodextrin is actually commonly used in the brewing of beer. Starches may also be added to preserve texture.

Water

Duh.

Spices and flavoring

Various spices and other compounds are used to add flavor. Smoke flavoring might be used, for instance, or beef stock, yeast extract or garlic. Smoke flavoring gives meat a ‘smoky’ taste without a grill. The rest of these ingredients are natural.

Casing

You can buy hot dogs that don’t have a casing, but it’s more about a preference of texture than health. Casings are either made with the lining of sheep intestine or with collagen (in the case of kosher hot dogs). Don’t freak out — people in many cultures eat sheep intestines/stomachs all the time, and do it safely. If listed, the ingredient will likely read “natural casing.”

Bottom line?

Every hot dog brand is different. Some brands prioritize simplicity of ingredients, while others don’t mind adding more ingredients in for the sake of aesthetics or flavor. It’s really up to you to check the label of whatever wiener you buy to ensure you’re OK eating everything listed there. If you’re not sure where to start, here’s a comprehensive guide to the healthiest and unhealthiest store-bought hot dogs.