Patent ID: 11891588
Assignee: ECOLAB USA INC.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 14:
15. A method of cleaning a metal surface to remove hard water deposits and/or lime comprising:
providing a liquid composition, comprising from 25 wt. % to about 35 Wt. % of citric acid;
from about 0.1 wt % to about 20 wt. % of surfactant;
a pH modifier in an amount so that the amount of free citric acid is less than 10%, wherein said pH modifier is sodium citrate dihydrate;
a preservative; and

from about 35 wt. % to about 65 wt. % of water;
wherein said composition is free of alkali metal hydroxides and alkanolamines and further wherein the method does not require the use of personal protective equipment.