To which substance does the general category of glycol-based antifreeze align for use in sprinklers?

The general category of glycol-based antifreeze that aligns for use in sprinklers is propylene glycol. Propylene glycol is commonly used in fire protection systems because it is recognized for its lower toxicity compared to other options, making it safer for environments where human exposure might occur and is often suitable for use in places where water is considered a potential contaminant.

Additionally, propylene glycol has effective antifreeze properties that allow it to function efficiently within the intended temperature ranges for fire sprinkler systems, particularly in colder climates where the risk of freezing could compromise the system's operation. Ethylene glycol is highly effective as well but presents much higher health risks, making it less favorable for many applications, especially where safety is a concern.

Glycerin and diethylene glycol do not fulfill the common requirements for sprinkler system use as effectively as propylene glycol does. Glycerin can be used in certain situations, but it doesn't have the same widespread acceptance and safety profile as propylene glycol for direct use in fire sprinkler systems. Diethylene glycol, while effective in temperature protection, does not have the same applications in fire systems and can present health hazards.

Thus, the use of propylene glycol demonstrates a balance of effective performance, safety, and compliance with relevant regulations for fire