"Chemical suits", "slickersuits", "Disposable boiler suits", "Chemical spray suits" etc: these are all really synomyns of the same thing: a chemical protective coverall.
There are 2 types Chemical resistant suits: reusable and disposable. The reusable chemical suits are made of heavier material, to withstand chemicals for longer periods. The benefit of reuse has to be offset by the recommendation of washing down the chemical suit after each use. Disposable chemical suits are paper thin, highly breathable and are very comofortable to wear over clothing. The benefit is that they can be used and binned after each use, without fear of cross contamination.
Alpha Solway brand is probably the UK leader in reusable chemical suits.
....remember Alpha Solway also does disposable chemical suits: The Alpha Solway Alphachem and the ChemMaster are used widely within UK oil, gas, chemical and pharma industries.
Dupont Tychem is the brand that has defined and developed the disposable boiler suit market. The Tychem is a good example, giving protection to EN14126 (infection protection)and to En1073 - radioactive agents
The Portwest BizTex disposable boiler suits are low linting - which can be important for cleanrooms, and very breathable - which is important for your comfort. These microporous suits are Certified to EN 13034 (chemical) and EN 14605 (liquid tight).