Perfluorobutanoic Acid (PFBA, C-4)CAS 375-22-4
Short-chain 'replacement' PFAS — much shorter half-life than PFOA but still persistent.
Toxic Chemical Databases
Substance-specific listings — these flags are for Perfluorobutanoic Acid alone, not for the broader family.
Chemical Type
Short-Chain C4 Perfluoroalkyl Carboxylic Acid
Chemical Description
PFBA is the four-carbon analog of PFOA — the carboxylic-acid end is unchanged, but the fluorinated tail is half as long. Industry shifted to short-chain replacements after PFOA restrictions; PFBA shows a human serum half-life of ~3 days versus PFOA's 3-5 years, which makes it less bioaccumulative. But it's still environmentally persistent (the C-F bond doesn't break), still mobile in water, and emerging cohort studies show thyroid effects at lower exposure levels.
Biological Activity
Severity scores specific to this substance, NOT the parent family average. Differences between siblings are real and meaningful.
Top Health Consequences
- Thyroid hormone disruption
- Liver enzyme induction
- Environmental persistence — no biodegradation of C-F bond
- Lower bioaccumulation than long-chain PFAS but rising drinking-water concentrations
Pathways of Exposure
- Drinking water contamination from fluoropolymer manufacturing sites
- Inhalation of degradation products from C-8 fluoropolymers
- Diet — emerging contamination of crops near contaminated sites
Building Materials with Perfluorobutanoic Acid
Listed alphabetically — product categories where this specific substance appears.
Replacement Fluoropolymer Coatings
Specialty Stain Treatments (Newer)
How We Keep Perfluorobutanoic Acid Out of a House
We do not knowingly install anything containing Perfluorobutanoic Acid. Our specifications name the chemistry we refuse, every submittal is screened against it, and substitutions are rejected — which is how a toxin free home stays that way through construction.
If you want a house specified this way from the start, or an existing house assessed for what is already in it, that is the work we do. Earth Bound Homes builds in Los Gatos, San Jose, Santa Clara County and across the San Francisco Bay Area.