Mitigating Hydrogen Plant HSE Hazards Around Edmonton

All fuels pose some amount of risk during processing and handling, but the unique properties of hydrogen compound the situation further. 

Hydrogen possesses a single-digit lower flammability limit and an overall wide flammability range and like most fuels, can be ignited by the energy in an average discharge of static electricity. When considering health, safety, and environmental concerns, hydrogen is essentially benign in the former and latter categories as it is both non-toxic and an important tool in decarbonizing the energy industry. However, Hydrogen plant hazards do present a very real danger to operators and equipment. Recent changes to Alberta workplace safety guidelines mean that renewed efforts must be made to remain in compliance.

A Simplified Overview of Federal and Provincial Safety Regulation

The federal Canadian Centre for Occupational Health and Safety (CCOHS) defines a hazard as the potential source of harm to a worker, but this can be applied more liberally to equipment and environmental damage. Hazard assessment is a single pillar of the overall risk assessment approach, which includes:

1. Hazard identification - Recognition of sources of potential harm
2. Risk analysis - Evaluation and possibly quantification of the level of risk associated with a specific hazard
3. Risk control - Elimination of the hazard or appropriate safeguards put in place to limit the potential of harm

In Alberta specifically, the new Occupational Health and Safety Act was enshrined in December 2021. The general thrust of the changes over the previous OHS Act involves the responsibilities of the various workplace entities, revisions to joint health and safety commissions, and some alterations to incident reporting and investigation in the event of injury. Administrative infractions can be penalized up to a rate of $10,000 per day and can be issued to any offending worksite party.

Analyzing the Types of Hydrogen Plant Hazards

Fines don’t spring out of thin air for no reason: they are meant to correct injury vectors and reduce the possibility and severity of future incidents. CCOHS has sorted some common sources of injury into various types. Broadly, the types of hydrogen plant hazards that a job site member is most likely to encounter are related to chemical, physical, safety, and ergonomic factors. Let’s take a look at each type:

Chemical

The chemical properties of hydrogen contribute the greatest share to its hazardous nature. Hydrogen is tiny, buoyant, and highly diffusive. It burns in volumetric ratios with atmosphere from 4-5% up to approximately 75% (in other words, hydrogen mixtures are rarely rich and seldom lean except for infinitesimal leaks). Hydrogen embrittles a wide variety of metal alloys and it combusts with a nearly colourless and odourless flame in broad daylight. 

A good rule of thumb: If hydrogen is leaking in appreciable quantities, it will ignite, creating a barely perceptible blue-tinged fire. The chemical factors which are responsible for hydrogen’s high hopes as an eventual replacement fuel for carbon-rich fuels also contribute heavily to its role as a workplace hazard.

Physical

Liquid hydrogen in a pressurized storage tank can undergo a boiling liquid expanding vapour explosion (BLEVE). Note that hydrogen boils at only a scant few degrees above absolute zero in standard temperature and pressure conditions. During a significant rupture event, the contents of the tank rapidly depressurize and the formerly closed system of gas and liquid hydrogen rapidly expands as the liquid contents immediately vaporize. Not only is the resultant shockwave and shrapnel highly dangerous, but hydrogen’s tendency towards autoignition while leaking means the BLEVE is likely to result in a fire as well.

Safety

A primary safety concern for hydrogen revolves around improper insulation of hose that may result in either burns or a slip, trip, and fall danger. Steam methane reforming produces temperatures above 800°C and liquid hydrogen needs to be kept below -250°C; even momentary contact with temperature extremes can cause severe burns. 

Insulation and ventilation also help prevent vapours from condensing on the outer surface of the hose, carrying cold fluid that could drip downward. Water accumulation would be a potential risk for a slip and fall incident were it to pool on the floor. Hose ran through tight spaces (e.g., through subflooring) alongside electronics may be a cause of electronic shock, smoke inhalation, or fire due to a water-induced short. Dynamic hoses, or hoses that are expected to flex and move during operation, can also cause injury if the motion is not appropriately damped. 

One final safety point: hydrogen is an asphyxiant, though its buoyancy means it is unlikely to cause suffocation except for large leaks in small, poorly ventilated spaces. As with all things safety, it is best to keep worst-case scenarios in mind while planning.

Ergonomic

Ergonomic hazards are relatively masked compared to the more immediately noticeable outcomes of the prior types of hazards. It is this quality that makes them rather insidious, as their deleterious effects tend to build up over an extended time frame. Although the entire list of equipment and training precautions lay beyond the scope of this section, one notable way to reduce ergonomic stress on welders is with an orbital welding unit and comprehensive training. For applicable jobs, an orbital welding unit will help reduce repetitive stress injuries associated with common welding tasks and prevent some instances of poor posture due to workpiece considerations such as weld direction.

Edmonton Valve & Fitting Helps Protect Your Most Important Asset

When it comes to workplace safety, you shouldn’t consider sparing any expense. Even from a purely financial perspective, an injury to any job site member can result in an increase in insurance premiums and potential fines by regulatory agencies. A plant may even be required to shut down to perform critical repair and maintenance in extreme situations. Much like fugitive emissions, systematic maintenance and review of hydrogen plant hazards will result in net savings by stopping the loss before its occurrence; as they say, an ounce of prevention is worth a pound of cure. Whether it is time to review your fluid system or replace components, contact an Edmonton Valve & Fitting Field Advisor to add an expert’s perspective to your safety toolkit.