No, caustic (specifically liquid caustic soda) is not a Volatile Organic Compound (VOC).
The statement is based on the definition provided in 40 CFR 51.100, which outlines the criteria for a substance to be classified as a VOC. Liquid Caustic Soda doesn't meet these criteria.
What are VOCs?
Volatile Organic Compounds (VOCs) are organic chemicals that have a high vapor pressure at ordinary room temperature. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and enter the surrounding air.
Why Caustic is Not a VOC
Liquid caustic soda is an aqueous solution of sodium hydroxide (NaOH). Sodium hydroxide itself is an inorganic compound, not an organic one. Since VOCs are, by definition, organic compounds, caustic soda (NaOH) does not qualify. Because VOCs are substances that evaporate at room temperature, caustic soda will also not evaporate, thus it doesn't fall under the VOC class.
In Summary
Liquid caustic soda does not contain constituents that qualify as volatile organic compounds (VOCs) based on regulatory definitions.
