Why the Chemical Industry Replaced CFCs With Orange Peels

By Ken Fry, Terps USA Research — sourced from Terps USA Research

Short answer

When the chemical industry was required to retire CFCs and chlorinated solvents like 1,1,1-trichloroethane on environmental and health grounds, it needed replacements that performed without the same toxicity profile. D-limonene, derived from orange peels, became the workhorse of that transition — now used as a parts cleaner, engine degreaser, and direct CFC replacement across multiple patented applications.

A phase-out that needed a real replacement, not a substitute in name only

The late twentieth century gave terpene cleaning a second life, driven by necessity rather than nostalgia. As CFCs and chlorinated solvents got phased out on environmental and health grounds, industry needed something that actually performed the same job without carrying the same risk.

Terpenes were the answer, and d-limonene led the way

With the phase-out of CFCs and trichloroethane, interest focused directly on terpene cleaners — most commonly d-limonene, derived from orange peels, with alpha- and beta-pinene from wood turpentine also in common use. D-limonene became a workhorse across a wide range of applications: parts cleaner, engine degreaser, tar and asphalt remover, and in a number of formulations, a direct replacement for chlorinated solvents and CFCs. It appears today across industrial degreasers, hand cleaners, and all-purpose formulations.

Why it qualified as the replacement

D-limonene's appeal in this transition was that it's potent yet plant-derived and biodegradable in many applications. As traditional organic solvents have gradually given way to eco-friendly alternatives, d-limonene is recognized as a terpene bio-solvent that meets many of the working criteria of a green solvent — documented across multiple U.S. patents specifically covering its use as a parts cleaner, engine degreaser, and chlorinated-solvent or CFC replacement.

The molecule doing double duty

D-limonene and the pinenes are the same compound families that define the aromatic character of citrus groves and pine forests. The molecule that cleans an engine block and the molecule that perfumes a citrus grove are, in many cases, the same molecule — which is the throughline connecting this industrial history to any terpene-based cleaning application, including post-harvest cannabis processing.

FAQ

Why did the chemical industry start using d-limonene as a solvent?

As the chemical industry was required to retire CFCs and chlorinated solvents like 1,1,1-trichloroethane on environmental and health grounds, it needed replacements without the same toxicity profile. D-limonene, derived from orange peels, became a workhorse solvent for many of these applications.

What is d-limonene used for as an industrial cleaner?

D-limonene has been used as a parts cleaner, engine degreaser, and tar or asphalt remover, and in a number of formulations as a direct replacement for chlorinated solvents and CFCs. It appears across industrial degreasers, hand cleaners, and all-purpose cleaning formulations, documented in multiple U.S. patents.

Is d-limonene considered a green solvent?

Yes. D-limonene is recognized as a terpene bio-solvent that meets many of the working criteria of a green solvent, valued for being potent yet plant-derived and biodegradable in many applications as traditional organic solvents have given way to eco-friendly alternatives.

Sources

1. Fry, K. (2026). "The Cleaning Tradition of Terpenes." Terps USA Research. DOI: 10.5281/zenodo.21246521

2. Fact Sheet: Terpene Cleaners Used for Industrial Cleaning, P2 Info House.

3. US Patents 5,405,547 and 5,549,839 (d-limonene as parts cleaner, engine degreaser, tar/asphalt remover, chlorinated-solvent/CFC replacement).

This article is for informational and industry education purposes only. Terps USA products do not contain THC or CBD. These statements have not been evaluated by the FDA. Readers are encouraged to consult the cited primary sources directly.