[Guest Columnist] The Case for Sanitary Welding

Stainless steel has become a standard material used for construction of product-contact equipment in the produce industry. As operators have adopted routine use of this material, I have noticed one issue that causes occasional concern. Quite often, stainless steel parts assembled into produce handling structures are welded together. While visiting produce packing and processing operations I have noticed wide variations in the quality of welds on production equipment. Welding is an art that involves a great deal of science. It is a skill requiring considerable knowledge and a great deal of judgment acquired only through practice. My observations lead me to believe that there is considerable variation in the welding skills of those constructing and repairing produce-handling equipment.

Many welds are rough and have excessive pitting along the joints that result in an area that is more or less impossible to clean. As small bits of product and soil are trapped in these areas they begin to provide a favorable environment for microbial growth. As this growth continues, biofilms that impede the effectiveness of sanitizing solutions used in cleaning processes begin to form. Biofilms are difficult to remove without some form of physical contact such as a brush. The size and orientation of voids in many welds I have seen makes physical cleaning difficult if not impossible resulting in the potential for a persistent source of microbial contamination. Given a reduction in sanitizer effectiveness, due either to misapplication or organic material overload, this could result in product contamination.

Sanitary welding is a welding practice that is thoroughly codified for use in the drug and dairy industries. The techniques of sanitary welding are well documented and clearly described in a number of resources that are easily located in an Internet search.

I encourage food facilities that have equipment with welded product contact surfaces to carefully inspect that equipment for weld quality and, where needed, have an experienced welder redo joints that may be providing uncleanable microbial harborage. When building or contracting for new equipment that will contact product, specify the quality of welding expected and check to ensure that the final product is in fact smooth and cleanable. AIB

The author is Vice President/Produce Division, IEH Laboratories and Consultants.