Chemical safety in the swimming pool and spa industry

By Glenn Smith, senior safety advisor at HazardCo, who outlines some of the risks and protections associated with handling chemicals in the swimming pool industry.

As industry members are aware, the pool industry isn’t just about digging holes, tying steel and laying tiles. It is a chemistry business.

Every pool builder, service technician and installer works with substances that can burn skin, damage lungs, corrode metal and create toxic gas if mishandled. Liquid chlorine, muriatic acid, calcium hypochlorite, stabilisers and flocculants are all common products on pool sites, but “common” should never be mistaken for “harmless”.

When you are handling oxidisers, corrosives and reactive chemicals, you are not just a builder, you are effectively a hazardous materials handler.

Whether you are working on a suburban backyard project in Auckland or a high-end residential home in Adelaide, the principles remain the same: keep your crew safe, protect the public, and stay compliant with your legal obligations.

Chemical safety is not red tape. It is a practical system that prevents injuries, avoids environmental damage, and keeps your business out of the spotlight for all the wrong reasons.

Here is a down-to-earth guide to chemical safety for the modern pool builder.

Respect the product

The most experienced pool professionals often develop a healthy attitude toward chemicals.

Not fear, but respect. The difference matters.

Fear can lead to overreaction or avoidance. Respect leads to good systems, proper training and consistent habits.

Most chemical incidents do not happen because someone lacked technical knowledge. They happen because someone got comfortable, rushed a task or assumed “I’ve done this a hundred times before”.

That attitude can result in acid burns, chlorine gas exposure, damaged vehicles or a call to emergency services.

The reality is simple: the chemicals you use every day are safe when handled correctly, and dangerous when they are not.

At the build site: mixing without the mishaps

Build sites are busy, noisy and deadline-driven environments. Pool builders are juggling excavation crews, steel fixers, plumbers, electricians, tilers and clients who want to know if they can swim by Christmas.

In that kind of environment, it is easy to cut corners.

Chemical safety on-site comes down to three fundamentals:

1. Protect yourself.

2. Keep chemicals separate.

3. Follow the right mixing sequence.

PPE is your first line of defence.

Your standard work gear is not enough when handling hazardous chemicals.

Sunnies, leather gloves and a dust mask might be fine for cutting pavers, but they offer limited protection against corrosive liquids and reactive powders.

When handling liquid chlorine or muriatic acid, your minimum personal protective equipment should include:

• Wraparound safety glasses or chemical splash goggles.

• A full-face shield for pouring larger quantities.

• Chemical-resistant nitrile or neoprene gloves.

• Long sleeves and long trousers.

• Closed-in boots.

• A P2 respirator if powders or fumes are present.

One splash of acid to the eyes can change a life in seconds. The right PPE is a small investment compared with the cost of an injury.

The “one at a time” rule.

Never mix different chemicals together in the same bucket, container or measuring cup.

Even products that appear stable can react violently when combined outside of the pool water. Some combinations generate heat, others release toxic gas, and some can ignite combustible materials.

Treat every chemical as though it must remain in its own lane until it reaches the pool.

Measure, add, rinse and repeat. No shortcuts.

The golden sequence.

Always add chemicals to water, never water to chemicals. This is one of the oldest and most important rules in chemistry.

Adding water to concentrated acid can cause an immediate exothermic reaction, creating a violent splash or “volcano effect” that can send corrosive liquid straight into your face and onto your skin.

The same principle applies to many powdered chemicals.

If dilution is required, fill the container with water first, then slowly add the chemical according to the manufacturer’s instructions.

Environmental awareness.

Build sites often have stormwater drains, gardens and neighbouring properties close by. A single spill can kill plants, stain concrete or enter waterways.

Keep spill kits readily available and ensure workers know how to contain and neutralise small incidents.

A bucket of absorbent material and a clear response plan can turn a serious event into a manageable inconvenience.

In the ute: the mobile hazard

For many pool builders, the vehicle is effectively a rolling chemical store.

That makes the ute, trailer or van one of the highest-risk environments for chemical incidents. Leaks, incompatible storage, and poor ventilation can turn a routine delivery into a dangerous situation.

Transporting chemicals safely is not optional.

If quantities exceed “tools of trade” exemptions, additional requirements under the National Transport Commission Australian Dangerous Goods Code and the New Zealand Transport Agency Waka Kotahi Land Transport Rule may apply.

No chemical cocktails.

Never transport acids and chlorine products directly next to one another. This is the cardinal rule of pool chemical transport.

If hydrochloric acid leaks and contacts sodium hypochlorite, the reaction can release chlorine gas, a highly toxic respiratory irritant that can incapacitate the driver in moments.

In confined vehicle spaces, this can quickly become a life-threatening emergency.

Separate incompatible substances using dedicated compartments or physically isolated storage bins.

Secure the load.

A 20-litre drum of acid rolling around in the tray is not just untidy, it is highly dangerous.

All chemical containers should be:

• Upright.

• Sealed.

• Restrained against movement.

• Protected from impact.

• Inspected for damage before transport.

Use purpose-built chemical bins or lockable cabinets fixed securely to the vehicle. If you can hear drums sliding when you brake, the system is not good enough.

Ventilation matters.

Enclosed vans require special attention. Even a minor leak can allow fumes to accumulate, creating a hazardous atmosphere for the driver.

Install floor or roof vents to ensure adequate airflow and regularly inspect the cargo area for signs of corrosion or chemical odour.

If you open the doors and immediately smell chlorine or acid, stop and investigate before driving any further.

The paperwork.

Every chemical should have an up-to-date Safety Data Sheet (SDS) readily available. These documents provide critical information on:

• Hazards.

• First aid.

• Spill response.

• Fire-fighting measures.

• Storage requirements.

If there is a vehicle incident, emergency responders need to know exactly what substances are involved.

Keeping SDSs in a folder or digital app is a straightforward and professional practice.

At the workshop: professional storage

Your workshop or depot is the backbone of your chemical management system. A spare corner of the shed is not enough.

Safe storage requires planning, segregation, containment, and accurate information.

The 3-metre rule.

Incompatible chemicals should be kept at least three metres apart unless a suitable fire-resistant and chemical-resistant barrier is installed.

This is particularly important for:

• Acids and oxidisers.

• Liquid chlorine and fuel.

• Reactive powders and combustible materials.

Segregation reduces the chance that a single leak becomes a major emergency.

Bund it up.

Secondary containment, commonly called bunding, is essential.

Use spill pallets or bunded cabinets capable of holding leaks from damaged containers. If a drum cracks overnight, the liquid should remain contained rather than spreading across the floor, entering drains, or reaching neighbouring properties.

Bunding is one of the simplest and most effective controls available.

Signage and placarding.

When stored quantities exceed regulatory thresholds, clear hazard signage and placarding are required at the site entrance and storage area.

These signs provide immediate information to workers, visitors, and emergency services.

Even where thresholds are not reached, good signage is a smart business practice. It communicates professionalism and reduces confusion during an emergency.

Inventory control.

Maintain an accurate chemical register that includes:

• Product names.

• Quantities.

• Storage locations.

• SDS references.

• Expiry dates.

A current inventory helps with compliance, purchasing, and emergency response.

It also prevents over-ordering and allows you to identify old or degraded stock before it becomes a problem.

Training: the control that ties everything together

The best storage setup in the world means little if workers do not understand the risks.

Everyone who handles pool chemicals should know:

• What each product does.

• Which chemicals are incompatible.

• How to use PPE correctly.

• What to do in the event of a spill.

• Basic first aid procedures.

• When to call emergency services.

Training does not need to be complicated.

Short toolbox talks, refresher sessions, and practical demonstrations are often more effective than lengthy manuals that no one reads.

The key is consistency.

Emergency preparedness.

No matter how good your systems are, incidents can still occur.

That is why preparation matters.

Every business should have:

• Eye wash facilities.

• Clean water for flushing.

• Spill kits.

• Emergency contact numbers.

• Clearly accessible SDSs.

• Workers trained in first response.

When something goes wrong, the first few minutes make all the difference.

Prepared crews respond calmly and effectively. Unprepared crews panic.

The cost of getting it wrong

Chemical incidents can result in:

• Serious burns.

• Respiratory injuries.

• Environmental contamination.

• Vehicle damage.

• Lost time.

• Regulatory penalties.

• Reputational harm.

For small and medium-sized pool businesses, one significant incident can disrupt operations for weeks and damage hard-earned trust.

Clients expect professionalism. Regulators demand compliance. Workers deserve to go home healthy.

The bottom line

Chemical safety is not about being afraid of the products you use. It is about respecting them.

The best pool builders understand that quality construction is not just measured by straight tiles and crystal-clear water. It is also measured by the systems behind the scenes that protect workers, clients and the community.

• Wear the right PPE.

• Keep incompatible chemicals apart.

• Transport them properly.

• Store them professionally.

• Train your team.

And never assume that “she’ll be right” is a control measure.

Because in the pool industry, a little chemistry knowledge and a lot of common sense go a long way.

Build great pools, but more importantly, build them safely.

IMAGE: PPE is the first line of defence. Image: AdobeStock