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Cleaner chemistry

Cleaning Chemistry: Acidic vs Alkaline Cleaners and What Never to Mix

Match the cleaner to the mess: acids for scale and soap scum, alkaline cleaners for grease, neutral for stone and wood, disinfectant dwell times and dangerous mixes.

Quick answer

Acidic cleaners remove mineral scale, rust and soap scum; alkaline cleaners cut grease and food soil; pH-neutral cleaners are safest on natural stone, wood and finished surfaces. Clean before you disinfect, and leave a disinfectant wet for the full contact time on its EPA-registered label. Never mix bleach with ammonia or with acids such as vinegar, which releases toxic gases.

Most cleaning problems are chemistry problems. Match the cleaner’s pH to the soil, and the surface will thank you.

Match the cleaner to the mess

Mess Cleaner type Examples
Hard water scale, rust, soap scum Acidic Citric, lactic or sulfamic acid descalers
Grease, cooking oil, food soil Alkaline Degreasers, dish soap, baking soda paste
General dust and light soil Neutral Multi-surface and stone cleaners
Mold and mildew stains Oxidizer Diluted bleach or oxygen cleaners, as labeled

Surface cautions

Surface Avoid
Marble, limestone, travertine Acids, including vinegar and lemon
Granite and quartz Harsh acids and abrasives; follow maker guidance
Hardwood Excess water, steam, harsh alkalis; see steam mop guide
Aluminum Strong alkalis
Stainless steel Chlorine bleach left to sit

Cleaning vs disinfecting

Cleaning removes soil; disinfecting kills germs on a cleaned surface. A disinfectant only works as labeled if you clean first and leave it wet for the full contact time. Look for an EPA registration number on any product making disinfection claims.

Never mix

  • Bleach + ammonia: toxic chloramine gases
  • Bleach + acids (vinegar, some toilet bowl cleaners): chlorine gas
  • Different drain cleaners: violent reactions

Ventilate, wear gloves, and store chemicals in their original containers.

Laundry has its own chemistry; see detergent types. Browse laundry and supplies.

Common questions

What cleaner removes hard water stains?

An acidic cleaner or descaler, such as one based on citric acid, used on surfaces that tolerate acid.

Can I use vinegar on granite or marble?

No. Acids can etch natural stone. Use a pH-neutral stone cleaner.

What happens if you mix bleach and ammonia?

It produces toxic chloramine gases. Never mix them, and do not mix bleach with acids either.

What is disinfectant dwell time?

The time the surface must stay wet for the label's kill claims to apply, often several minutes.