Simultaneous Operations Safety

April 17, 2018

Simultaneous Operations and Identifying Health Hazards - Chemscape Chemical Safety Technologies Inc.

Do you have Concurrent or Simultaneous Operations in your organization? Could one operator’s tasks be unknowingly generating health hazards for others? Learn how to quickly Identify, Communicate and Control Chemical Hazards and Health Risk at these job sites. Our safety expert John Artym and Industrial Hygienist Mike Phibbs CIH ROH face off.

At many jobsites there are multiple operations occurring at the same time. Imagine welding, abrasive blasting and coating all taking place at the same location at the same time. The execution of two or more tasks by two or more functional groups on the same location at the same time are referred to as Simultaneous or Concurrent Operations “SimOps”.

Simultaneous Operations Safety

Being effective at ensuring health and safety at the workplace requires commitment (from management and workers), resources, and a mature Health and Safety Management System. This challenge increases in complexity on a jobsite with SimOps or Concurrent Operations. We will define Simultaneous or Concurrent Operations “SimOps” as the execution of two or more tasks by two or more functional group activities on the same location at the same time. You are more likely to find SimOps during construction or when major maintenance work is being done within a “live” process area of an existing facility, on multiple well pad operations and multiple contractor facilities.

Safety View on SimOps Hazard Management

Industrial Hygienist View on SimOps Hazard Management

During SimOps, organizations must consider how the hazards can be transferred or released to other functional groups.


Think of an example in construction or fabrication:  Equipment is being manufactured and/or fabricated at a jobsite where several hazardous chemicals are being used or created (i.e. welding fumes, toxic paints, abrasive blasting). Does your Chemical Management system or SimOps plan account for the electrical crew working downwind from the sand blasting operations? Are the painters working alongside the welders aware of the hazard and potential occupational health harms of the welding fumes?

The concern is that while performing independent operations, these activities and/or events may impact the health and safety of personnel or equipment or the environment of another operation. Specifically, with respect to Chemical Management and preventing exposure to workers both the physical and occupational health risks must be managed. First, to control the chemical hazards during SimOps a thorough hazard assessment should analyze each chemical and its ingredients. It is important to KNOW the Hazard. Secondly, the risk needs to be determined based on utilization (quantity, volumes, time, volatility), the task being performed and the effectiveness of the controls and measures. Who is in control of the chemical? Remember to include all your Manufactured Products, Process Additives or Shop Supplies.

Key Considerations:

1.      Do you have systems in place to maintain the Chemical Inventory, complete the hazard ranking/grouping and can communicate the hazards and controls/measures?

2.      Consider the task being performed. Will workers encounter those chemicals or their by-products? Has the physical state changed (e.g. bentonite with crystalline silica in a solid state mixed into a liquid solution)? Has the risk changed?

3.      Are the engineering controls changing (e.g. hazardous product is contained in a piping system, but containment must be broken to change filters or take samples)?

4.      Is there an energy source that will transfer the hazardous chemical or harms into concurrent operations (e.g. failure of a pressurized system spreads liquids containing BTEX across the jobsite)?

5.      Do the administrative controls and measures, PPE/RPE requirements apply for all the crews/workers on the jobsite? Consider who is at risk.

6.      Success is based on concise and on-going communication. Do your systems and “plan” demand expectations? When SimOps are planned or identified, it is important that all relevant and involved parties are include in the SimOps plan.

At multi-employer work sites with multiple hazards Industrial Hygienist need to focus on identifying and communicating the health hazards and risks in these situations. For example, on a job site you may have abrasive blasting, welding and coating tasks all taking place at the same time. We often focus on the individual tasks and hazards and focus on controlling the hazard for that task and the individual(s) involved. But on a busy job site there is typically numerous activities going on. Employers must protect their workers for the sum of the hazards on the job site regardless of who introduces a hazard. Chemical hazards do not respect fence posts or boundaries between tasks and when you add in the factor of wind these individual health hazards interact and pose additional health hazards.


In this common situation the hazards and risk need to be quickly determined. Controls need to be determined. Which party will determine what is acceptable? Who will implement? Who will bear the costs? How will this be communicated at the job site so others will act?

There are two professional trains of thought among the IH community and let’s call them System 1 vs. System 2 thinking. System 1 is automated – control first and then monitor. System 2 is calculated – monitor and then control. Health hazards lend themselves to System 1. IH’s commonly adhere to System 2. But daily exposure for workers need immediate action. Operations don’t cease for measurement, study and recommendations for exposure reduction that can take weeks to conclude.

Risks are not controlled if your hazards are not known. This returns to the foundation of doing a thorough hazard inventory. Being aware of all known health hazards. Having a discussion on how hazards transfer across workspaces. Will one operator’s tasks generate health hazards for others? Do controls for one work space apply to all?

Have you decided who is ”Prime” or how many “Primes” are at the site? The Prime Contractor on a jobsite is obligated to protect workers. But what if there are multiple primes on a jobsite? Is everyone in agreement?

It is important to define physical and task boundaries. Do Minimum PPE and Administrative Controls apply universally? Do Engineering Controls cause interactions? i.e. LEV vents towards others. Do controls change with the task?

Simplified and clear communication is important in this situation. Who is responsible to communicate the information to certain groups and in what level of detail? Icons and Images are effective to communicate information quickly and reach audiences who may have language and literacy challenges.


Managing SimOps Hazards

The quicker you identify chemical hazards, understand potential interactions and communicate concisely the more effective you will be at preventing harm from chemical exposure(s) during Simultaneous Operations or Concurrent Operations. Commitment and communication from the project Owner, the Prime Contractor(s), and Contractors on the site is critical to effective management the numerous challenges encountered on a SimOps work site.