A look at quality assurance beyond existing Industry Standards and typical Quality Assurance Programs, regarding the installation and fabrication of construction materials in "highly toxic and hazard" chemical service.

The "highly toxic and hazard" chemicals procedure includes a careful and thorough process includes the following:

  • 100% X-Ray of all welds where feasible.
  • 100% dye check of all weld root passes.
  • Specification of construction materials for each application.
  • Positive material verification (PMI) of the selected material, prior to installation.
  • A consistent revision of the product and service indices for each area that processes "highly toxic and hazard" chemicals.
  • Receiving examination where personnel should follow minimum practices and procedures.

The aim of the "highly toxic and hazard" chemical system is to reduce the likelihood of construction material failure in designated chemical services to the probability of a frequency > 100,000 years.

The "highly toxic and hazard" chemical is a substance whose uncontrolled release has catastrophic consequences with a significant potential to cause:

  • multiple fatalities on the facility and surrounding communities
  • a multi-million dollar loss in business or property

The "highly toxic and hazard" chemicals are designated as such based on:

  • the hazards of a given chemical
  • the quantities involved
  • compatibility with construction materials

Some of the "highly toxic and hazard" chemicals in the industry are:

  • Hydrazine (N2H4)
  • Hydrogen Fluoride (HF)
  • Mercuric chloride (HgCl2)
  • Oleum (H2O7S2 )
  • Sodium cyanide (NaCN)
  • Sodium Trioxide (SO3)

Procedures to identify "highly toxic and hazard" chemicals include:

  1. Designating on construction request, projects, work and purchase orders that a "highly toxic and hazard" chemical is involved and no substitutes are acceptable for the specified construction materials. When personnel make requisitions/orders for "highly toxic and hazard" material they must state on the order that material is "highly toxic and hazard" in the description and the material must come with a tag indicating the material is "highly toxic and hazard". When performing construction, personnel receives "highly toxic and hazard" equipment or parts, they should verify that material received/ordered matches requested equipment and contact inspection personnel for "highly toxic and hazard" inspection.
  2. At least one confirmation, where possible, of the specified proper metallic alloy material of construction through hand held x-ray fluorescence positive material identification when received, fabricated, or immediately prior to installation.
  3. Other methods and techniques are available for positive material identification of the material of construction and should be identified by consulting with the materials engineers as required.
  4. Tagging of equipment and materials as received, fabricated, or stored, and tagging removed during installation.
  5. All equipment should be 100% X-Ray per ASME Code Category M Fluid Service. As a minimum, the root pass of all piping should be penetrant tested. This is a minimum requirement and the Materials Engineer or Inspector may require additional and more stringent testing or criteria. A "highly toxic and hazard" quality assurance is an integral part of the total hazards management effort, and as such, it is an operating area responsibility for assessing where this additional assurance is necessary and what specific verification steps are required to meet the goals of "highly toxic and hazard" chemicals.