Safe Weighing: Minimising Risk in Hazardous Industrial Environments

When we talk about safe weighing practices in hazardous industrial environments, it’s not just about ensuring the scales are balanced. It’s about creating a safe space for employees, ensuring accurate results, and adhering to stringent safety standards. In these challenging settings, the stakes are high, and the margin for error is low. Whether dealing with volatile chemicals, explosive materials, or heavy machinery, the context of weighing in these environments is complex and demands attention. Safety is paramount, and understanding its importance is the first step towards minimising risks.

Before diving into weighing practices, it’s crucial to understand what constitutes a hazardous environment. Industries such as pharmaceutical, chemical, petrochemical, and food processing often handle volatile substances where a single spark could lead to a catastrophic event. These environments are typically classified under various regulatory standards like ATEX in Europe and NFPA in North America, which categorize areas based on the likelihood and frequency of explosive atmospheres.

Since Brexit, the UK has replaced the ATEX certification, which is used in the European Union for equipment intended for use in potentially explosive atmospheres, with the UKCA (UK Conformity Assessed) marking. The UKCA marking is now the standard for products in this category being sold in Great Britain. This change took effect from January 1, 2022, with a transition period allowing the use of CE marking until December 31, 2021, under certain conditions.

Additionally, it’s important to note that different rules apply in Northern Ireland. For products that can use a UKCA marking in Great Britain, EU rules, including CE marking, must be met in Northern Ireland. The UKCA marking is not recognized in the EU, so products intended for the EU market still require a CE marking.

Hazardous Industrial Environments

These environments are typically areas where there’s a risk of explosion, contamination, or exposure to harmful substances. Some examples include:

• Chemical Plants: Where volatile chemicals are processed and combined.
• Pharmaceutical Manufacturing: Environments that require strict hygiene controls.
• Oil and Gas Facilities: Where flammable gases or vapours may be present.
• Grain Processing Plants: Dust explosions are a known risk in these settings.
• Paint Manufacturing Plants: Flammable solvents are often used in these processes.

Common Hazards in Industrial Weighing Environments

Industrial facilities contain a diverse range of potential hazards that must be addressed to enable safe, accurate weighing.

Dust Explosions

Fine dusts are common in industries like agriculture, chemical production, and metal processing. Dust explosions can occur when airborne dust ignites, rapidly combusting in a chain reaction. This presents a grave threat to worker safety and facility integrity. Strict dust control is critical.

Corrosive Chemicals

Corrosive substances like acids and chlorine are used extensively in industrial processes. Exposure damages weighing equipment, compromising performance. Corrosion-resistant designs and materials are essential.

High Temperatures

Weighing equipment near furnaces, dryers, and other heat sources endures temperature extremes. Prolonged high temperatures accelerate component wear and degrade calibration. Careful temperature monitoring and compensation are needed.

Key Components for Safe Weighing

Precision is the name of the game when it comes to safe weighing. The instruments used must be of the highest quality, ensuring accurate and reliable measurements. But it doesn’t stop there. Regular maintenance and calibration are essential. These instruments are the backbone of safe weighing practices, and keeping them in top condition is non-negotiable.

But what about the human aspect? Employees must be well-versed in safety protocols and procedures. They need to undergo rigorous training and education, ensuring they are prepared for any situation. And of course, the right safety gear and equipment must be readily available and in perfect condition.

Here are some key considerations for selecting scales for safe weighing in hazardous industrial environments:

Risk Assessment, Zone Classification, and Equipment Selection:

Safe weighing practices in hazardous environments begin with a thorough risk assessment and zone classification. Identifying areas classified under standards such as ATEX or NFPA, where explosive gases, vapors, or dust might be present, is crucial in mitigating potential hazards. Selecting the appropriate weighing equipment is equally important. Equipment used in these areas must be specifically designed and certified, adhering to standards like ATEX, IECEx, or similar certifications. This ensures they are built to operate safely in explosive environments.

Specialized Equipment for Specific Environments:

• Explosion-Proof Scales: Certified for use in locations with flammable vapors or dust, designed not to be a source of ignition.
• Corrosion-Resistant Industrail Scales: Essential when handling corrosive chemicals, often made with stainless steel components like AISI 304 or AISI 316 (Read our Complete Steel Grade Guide for Industrial Scales here). Examples include Xtrem Cayman S, Xtrem Condor S, Xtrem Crocodile S, Xtrem Scorpion S, K3i Zebra S or TCamel Inox V4A, which are often HACCP-Compliant.
• Waterproof and Weatherproof Industrial Scales: Necessary for washdown or outdoor use, typically rated with IP65. If you’re unfamiliar with IP-ratings – Read our IP Grade Guide for Industrial Scales here.
• Intrinsically Safe Scales: These limit energy to non-ignition levels in extremely flammable environments and may require compatible peripherals.
• High-Resolution Scales: Suited for precision weighing of toxic or potent compounds, such as analytical or microbalances with 0.1 mg precision or less.

Intrinsically Safe Design and Regular Maintenance:

The concept of intrinsic safety is key in the design of hazardous area equipment. This approach ensures that, even in the case of component failure, the equipment cannot release enough energy to ignite a flammable atmosphere. Regular maintenance and calibration of this equipment are vital to prevent inaccurate readings and potential sparks from malfunctioning equipment.

Operator Training and Digital Advancements:

Human error is a significant risk factor in hazardous environments, making comprehensive training programs for operators indispensable. They should focus on the specific risks and safe operation of weighing equipment. Additionally, digital scales are preferred over analog pressure gauge types to avoid issues with mercury.

Load Cells and Decontamination:

Load cell scales are beneficial as they can often be located in hazardous areas, while indicators are safely out of the hazard zone. Scales with easy-to-decontaminate surfaces, like stainless steel platforms with minimal seams and crevices, are ideal for maintaining cleanliness and safety in these settings.

The right combination of hazardous area rating, construction materials, and weighing capabilities should be selected to match the specific safety requirements in the plant.

Advanced Weighing Systems for safe Weighing 

In hazardous industrial environments, the weighing systems used need to be robust, accurate, and reliable. Here are the typical weighing systems utilised:

• Industrial Scales: These scales are designed for the rigorous demands of industrial environments. They offer durability and precision for a variety of industrial weighing needs, from light-duty applications to heavy industrial uses. Industrial scales are built to withstand harsh conditions and provide reliable measurements even in challenging settings.
• Platform Scales and Floor Scales: These are heavy-duty scales designed for weighing large loads. Many are equipped with safety barriers or guides to ensure accurate and safe loading.

Weighing Equipment for Hazardous Areas

Specialised weighing components are necessary for reliable performance in risky industrial environments.

Load Cells

Load cells used in hazardous areas should have ingress protection ratings of IP67 or higher to prevent dust and moisture damage. Hermetically sealed designs further improve corrosion resistance. Stainless steel or nickel-plated alloy are suitable load cell materials.

Junction Boxes and Cables

Junction boxes should be sealed to IP67 or better. Conduit and cable glands provide secure, dust-proof cable connections. Cables must be specially rated for high temperatures and chemical exposure.

Weigh Modules/Transmitters

Weighing terminals and transmitters with IP and NEMA ratings matching the environment ensure electronic components remain protected. Intrinsically safe circuits prevent sparks.

Identifying and Assessing Risks

Recognising hazardous materials and understanding their potential risks is a critical step in safe weighing. Implementing risk assessments helps in identifying potential hazards and determining the necessary safety measures to mitigate these risks.

What are we weighing? And what are the risks involved? Recognising hazardous materials is a crucial part of the process. It’s not just about identifying them but understanding their properties and potential risks. This is where risk assessments come into play. They help in pinpointing potential hazards and devising strategies to mitigate these risks. The role of risk assessments cannot be understated; they are a fundamental component of safe weighing practices.

Here are a few key points for identifying and assessing risks when working with hazardous materials in industrial environments:

• Conduct a thorough hazard analysis of all materials, processes, and equipment. Identify any intrinsic hazards (e.g. flammability, toxicity) and potential accident scenarios.
• Evaluate the probabilities and potential consequences of identified hazards and accident scenarios. Consider factors like quantities involved, frequency of exposure, number of employees exposed, and control measures in place.
• Prioritise hazards based on risk level (probability x severity). Focus greatest efforts on minimising the highest risks first.
• Involve site safety personnel to leverage their expertise in hazard ID and risk assessment. Walk through facilities to identify hazards.
• Review accident and inspection records to identify problem areas or risks that may have been overlooked.
• Consider both routine and non-routine activities. Maintenance, testing, startup/shutdown procedures often pose special risks.
• Account for human factors like inadequate training, fatigue, or taking shortcuts that could undermine engineered controls.
• Reassess risks periodically and after any process or operational changes at the facility.

The goal is to systematically identify all significant hazards, understand their mechanisms, likelihoods and potential consequences, and prioritise resources on the highest risk scenarios. Ongoing awareness and analysis is key to minimising risk.

Best Practices for Safe Weighing in Hazardous Environments

• Use proper protective equipment like chemical-resistant gloves, aprons, face/eye protection. Have proper PPE readily available.
• Minimise exposure time when handling hazardous materials on scales. Use the smallest quantities needed and move materials quickly.
• Have proper containment and spill control ready in case of leaks or spills during weighing. Absorbent pads, neutralising agents, bins etc.
• Ensure scale calibration and performance is routinely verified using calibrated test weights. Accuracy is critical when weighing hazardous substances. Read our Guide on How to properly calibrate your commercial scales and maintain accurate weighing.
• Establish and follow strict protocols for taring containers and cleaning the weighing surface between different chemicals. Avoid cross-contamination.
• Train personnel on scale operation, handling procedures, emergency response, and proper cleaning/decontamination methods.
• Position scales in well-ventilated areas to prevent exposure to toxic or corrosive vapour buildup.
• Locate scales away from open doorways or through-traffic areas to prevent accidental exposure of others. Use physical barriers as needed.
• Verify any intrinsically safe scales are installed per requirements and inspected/certified as needed to maintain the rating.
• Follow manufacturer recommended inspection and preventive maintenance schedules for scales.
• Prohibit unattended weighing. Keep hazardous materials under the direct supervision of trained personnel.

Best Practices for Safe Weighing

Adhering to proven guidelines maximises safety for personnel, equipment, and facilities.

Dust Control

Vigilant housekeeping and proper ventilation keep airborne dust within safe limits. Avoid locating weight modules in extremely dusty areas. Explosion suppression systems provide an extra layer of protection.

Corrosion Protection

Frequent washdowns remove corrosive buildup from equipment. Careful chemical handling prevents spills. Sacrificial anodes absorb corrosion instead of functional components.

Temperature Monitoring

Installing temperature transmitters near weighing systems enables real-time monitoring and alerts for excessive heat. Automated temperature compensation preserves accuracy.

Emergency Stop Buttons

Strategically placed emergency stop buttons quickly halt weighing processes if dangerous conditions develop, limiting harm.

Regular Safety Audits and Standard Operating Procedures

Maintaining a safe environment requires constant vigilance. Regular safety audits are essential, ensuring that all procedures are being followed to the letter. But it’s not just about checking boxes. Implementing standard operating procedures helps in creating a uniform approach to safety, making it easier to identify and rectify potential issues.

Leveraging Technology for Enhanced Safety

Technology is our friend in these scenarios. Utilizing cutting-edge solutions can enhance safety measures, ensuring that employees are protected at all times. And let’s not forget about data accuracy. Accurate results are crucial, and ensuring the reliability of data is a key aspect of safe weighing.

Encouraging Employee Involvement and Responsibility

Employee involvement and responsibility play a crucial role as well. It’s about fostering a culture of safety, where every employee feels responsible for their own safety and the safety of their colleagues.

Conclusion and Key Takeaways

Safe weighing in hazardous industrial environments is a complex yet crucial aspect of industrial operations. It requires a combination of precision instruments, comprehensive safety protocols, and a proactive approach to safety. By adhering to best practices, continually assessing and mitigating risks, and fostering a safety culture, industries can protect their most valuable asset—their employees.

FAQ’s – Frequently Asked Questions