Passivation of Stainless Steel Contact Parts of Production Equipments

To provide a procedure for passivation of Stainless steel contact parts of equipments located in the Production department. 

It is applicable to the SS product contact parts of the equipments used for manufacturing in the Production department. 

  • Operator / Engineering personnel: To passivate the SS product contact parts of the equipment as per this SOP. 
  • Production Supervisor: To monitor and record the details of passivation exercise as per this procedure. 
  • QC personnel: To collect and analyze the rinse sample as per pertinent procedure. 
  • Production Manager / QA Manager: To ensure that the SOP is followed. 
  • Clean the equipment using lint free dry cloth. 
  • Prepare 20 % citric acid solution in quantity sufficient to passivate the SS product contact parts of the equipment. 
  • Soak a clean cloth in the prepared solution of citric acid and wipe the SS product contact surface of the equipment using the soaked cloth. 
  • Then clean the product contact part of the equipment with Purified water. 
  • After the purified water has been drained off, again wipe the contact surface with cloth soaked in 20 % citric acid solution. 
  • Ensure that the entire product contact surface of the equipment is in contact with 20 % citric acid solution. 
  • Hold the equipment in same condition for around 14 – 16 hours. 
  • Finally, flush the contact part of equipment with Purified water till the rinse sample meets the specifications of Purified water (i.e. all the physical, chemical and microbiological specifications of Purified water are complied). 
  • Q.C. personnel shall be intimated to collect and analyze the rinse sample. 
  • Record the details of passivation activity as per Attachment-1: ‘Equipment Passivation Record’. 
  • Frequency of Passivation: Before operation of new equipments and as when judged necessary by the Production Manager or QA Manager. 
SOP: Standard Operating Procedure
QC: Quality Control
QA: Quality Assurance
SS: Stainless steel

Attachment-1: Equipment Passivation Record

Name of the Equipment: _____________

Department: ______________________

Equipment ID Number:______________


Sr. No.

Description of activity

Performed By/ Date

Checked By / Date


Equipment cleaning before Passivation




Preparation of 20 % citric acid solution

(Quantity = ___________ L)




Contact time of 20 % citric acid solution with Equipment surface to be passivated = ____________ hours.

(Time started:________      Time completed: ________)




Rinse sample collection




Rinse sample analysis




Rinse sample analysis result (Pass / Fail): ____________     

Sign / Date: _________________


Approved By: _________________ (QA Manager)


Authorized By: _________________ (Plant Manager)


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