Polycarbonate (PC) Chemical Resistance & Properties

PC has moderate chemical resistance. It performs well against dilute acids, alcohols, aliphatic hydrocarbons, and many aqueous salt solutions — but degrades quickly on contact with strong alkalis (sodium hydroxide, potassium hydroxide, ammonia), ketones (acetone), aromatic hydrocarbons (benzene, toluene), and concentrated strong acids. What makes some of these particularly dangerous is that damage can begin internally as stress cracking or swelling before it becomes visible on the surface. Always check the resistance chart for your specific chemical and concentration before specifying PC for any chemical-contact application.

PC's glass transition temperature is approximately 147 °C (297 °F), but in practice the continuous-use limit is typically 115–130 °C. The gap exists because sustained mechanical load causes gradual dimensional change — creep and stress relaxation — before any visible deformation occurs. When chemical exposure combines with elevated temperature, degradation accelerates further. For fluid handling applications that run hot, PVDF or PTFE-lined components are generally the safer choice.

PC and acrylic (PMMA) look nearly identical and are often used in similar applications, but they have a clear division of strengths. PC is significantly tougher — it resists impact far better (up to 250× glass vs. acrylic's ~17×) and can be cold-bent without cracking. Acrylic is more brittle but has better surface scratch resistance and offers slightly higher optical clarity (~92% light transmission vs. PC's ~88–90%). For chemical resistance, neither handles ketones or aromatic solvents well. The practical rule: choose PC where toughness and impact resistance take priority; choose acrylic where scratch resistance and optical perfection matter more and impact loads are low.

Polycarbonate is not considered toxic under normal use conditions. The concern most commonly raised involves bisphenol A (BPA) — an industrial chemical used as a structural component in polycarbonate, present in food-contact PC applications since the 1960s.² Small, measurable amounts of BPA can migrate from packaging into food — but based on the FDA's ongoing safety review of more than 300 scientific studies, BPA is safe at the levels occurring in foods from currently approved uses in food containers and packaging.²

It's worth noting that PC-based baby bottles and sippy cups were removed from FDA regulations — but this was because manufacturers had already abandoned those uses, not because of a safety finding.² For industrial fluid handling, the more relevant question is chemical compatibility: whether the process fluid attacks the PC component, not whether PC itself is hazardous to handle.

PC is a practical choice for rotameters, sight glasses, and level indicators where visual confirmation of flow or fluid level is needed. Its high optical clarity and impact resistance make it well suited for transparent fluid-contact components under moderate conditions. The key constraint is chemical compatibility: verify the process fluid against the resistance chart before specifying PC, and confirm operating temperatures stay within the continuous service limits. For aggressive chemicals or high-temperature streams, borosilicate glass or PVDF are more appropriate alternatives.

LORRIC's rotameter lineup includes PC tube options for clean water, cooling water, and low-aggression fluid monitoring applications. View LORRIC rotameters →

Avoid exposing PC to: strong bases (sodium hydroxide, potassium hydroxide, ammonia, ammonium hydroxide, barium hydroxide, calcium hydroxide), ketone solvents (acetone), aromatic hydrocarbons (benzene, toluene), chlorinated solvents, and concentrated strong acids including hydrochloric acid, sulfuric acid, and hydrofluoric acid. These cause rapid degradation — stress cracking, swelling, or dissolution — often without obvious surface warning at early stages. All are marked ✕ in the resistance chart above.