Chlorination & sanitization of chlorine dosing tank


  • To lay down a procedure of Chlorination & sanitization of chlorine dosing tank.


  • This SOP is applicable for the chlorination process and sanitization of the chlorine dosing tank in the formulation plant.


  • Operator / Technician shall be responsible for chlorination and chemical sanitization of chlorine dosing tank.
  • Engineering personnel shall be responsible for checking the chlorination & sanitization.


  • Department Head & QA Head shall be accountable for the implementation of this SOP.

Abbreviations and Definitions

  • QA:            Quality Assurance
  • SOP:            Standard Operating Procedure
  • QC:           Quality Control



  • Chlorination shall be done by 6.0% w/v sodium hypochlorite solution.
  • Take 45 liters of fresh raw water in a dosing tank.
  • Prepare the sodium hypochlorite solution having a concentration of 6.0 % w/v.
  • Add 5 liter of prepared sodium hypochlorite solution into the dosing tank and stir with S.S. ladle to form a uniform solution.
  • Maintain the free chlorine level is about 2 ppm by adjusting the dosing rate.
  • After chlorination, the sampling valve of the sampling point shall open and water shall be drained for at least five minutes.
  • Water sample shall be taken by the operator from sampling point no. and this sample shall be sent to QC to check the free chlorine level in the water.
  • Sodium hypochlorite solution preparation & consumption record shall be maintained as per annexure-I
  • Frequency: Daily


  • Drain the content of the dosing tank.
  • Clean with raw water.
  • Take 50 liters of potable water in the dosing tank.
  • Add 50 ml of sodium hypochlorite solution (6% w/v concentration- Approx.) in the dosing tank & stir with the help of S.S ladle.
  • Remove the dosing pump tubing from the dosing line & put it into the dosing tank and run the dosing pump for 30 to 60 minutes.
  • Keep the tank filled with sodium hypochlorite solution for 4 hours.
  • Clean the tank with potable water having 1-2 ppm of available chlorine.
  • After completion of cleaning, the tank is ready to use.
  • Sanitization of chlorine dosing tank shall be planned in a holiday to avoid the shortage of water.
  • Sanitization record shall be maintained
  • Frequency: Monthly

Forms and Records (Annexures)

  • Sodium Hypochlorite Solution Preparation & consumption Record –        Annexure-I
  • Sanitization of Chlorine Dosing Tank                                        –        Annexure-II


  • Master copy        –             Quality Assurance
  • Controlled copies –             Quality Assurance & Engineering


Date Revision Number                  Reason for Revision
0    New SOP


Sodium Hypochlorite Solution Preparation & Consumption Record

Date Qty. received Received  by Qty. used Balance Qty. Sodium Hypochlorite Solution Preparation (NaOCl) Checked by
Qty. of NaOCl Qty. of water Total Quantity Prepared Solution Prepared by


Sanitization of Chlorine Dosing Tank

Date Chemical Used Chemical Prepared by Conc. of Chemical Soaking  Time of  Tank & Dosing Pipes Done by Checked by
From To