A newer ingredient that is a glucose based surfactant. While there isn't a lot of data yet about this ingredient general indications are that it appears to be safe and non-toxic but that it can cause allergic contact dermatitis.

Denatured alcohol is ethyl alcohol with additives (usually methanol) that makes it unsuitable for consumption. It is used in place of alcohol since the additives alter it so that manufacturers don't have to pay taxes on it as an alcohol. Seriously. 

Ethanol acts as a penetration enhancer for many chemicals.

Methanol (if that is the additive) has links to moderate non-reproductive organ system toxicity.

Also called SD alcohol 

A silicon based ingredient that helps to provide skin conditioning. It is linked to organ system toxicity and is not planet friendly (ecotoxicology).

An anionic surfactant, generally regarded as safe.

There is a link to non-reproductive organ system toxicity at moderate doses hence there is a formulation limitation for use in human cosmetics.

A type of alcohol that is used in cosmetics and skincare products to improve the texture and stability of the formulation. Has low concerns for endocrine disruption (low), Non-reproductive organ system toxicity (low), and Irritation (skin, eyes, or lungs) (moderate). Can increase absorption on the skin and especially around the eyes. 

Used to help control viscosity. It is not a bad ingredient but it does enhance skin absorption which is ok if the remaining ingredients are safe. Not so great if they pose a health threat. 

Used as a preservative that slowly releases small amounts of antimicrobial formaldehyde over time. Many dogs have or can develop formaldehyde allergies/sensitivities. It also may cause skin or eye irritation. Formaldehyde is linked to cancer. 

An antimicrobial preservative that slowly releases formaldehyde.

Many dogs have or can develop formaldehyde allergies/sensitivities. Formaldehyde is linked to cancer.