How to Avoid Skin Irritation When Using CNC Coolants?

milling marking process with CNC coolant

CNC coolants are essential in machining. They help keep tools cool, reduce friction, and make cutting smoother and more efficient. However, these coolants can sometimes cause skin irritation for machinists who work with them daily. It’s a problem that many face but can often be avoided with the proper precautions. This can lead to redness, dryness, or even rashes. In this article, we’ll explore why CNC coolants may irritate your skin and what steps to take to protect yourself.

What Causes Skin Irritation From CNC Coolants?

Skin irritation from CNC coolants happens because of how they interact with your skin. These coolants contain chemicals designed to improve machining, but some can be harsh on the skin. 

Here’s what usually causes the problem:

Harsh Chemicals

Many CNC coolants have additives like biocides, rust inhibitors, and surfactants. These chemicals prevent bacteria growth, protect metal, and improve coolant performance. But they can also strip the skin of its natural oils, leading to dryness and irritation.

Prolonged Contact

Frequent exposure to coolants increases the risk of irritation. Coolants that sit on your skin for long periods can break down the protective barrier, causing redness, itching, or even rashes.

High pH Levels

Some coolants are alkaline, with a high pH level. This can disrupt the skin’s natural pH, making it more sensitive and prone to irritation.

Dirty or Contaminated Coolants

Old or poorly maintained coolants often collect bacteria, fungi, and other contaminants. These additional harmful substances can irritate the skin even more than fresh coolants.

Allergic Reactions

Certain individuals may be allergic to specific chemicals in the coolant. Even minimal exposure can trigger an allergic response, such as swelling, redness, or severe itching.

Identifying Harmful Chemicals in Coolants

Not all CNC coolants are skin-friendly. Some comprise chemicals that can cause irritation or allergic reactions. Knowing what to look for can help you choose safer options and reduce health risks.

Biocides

Biocides are added to coolants to prevent the growth of bacteria and fungi. While they keep the coolant clean, they can be harsh on your skin. Common biocides, such as formaldehyde-releasing agents or isothiazolinones, are known irritants. Check the label for these names and handle them with care.

Surfactants

Surfactants help coolants spread evenly across surfaces. They break down oils and greases, but they can also remove the natural oils from the skin. After prolonged exposure, this can lead to dryness and sensitivity.

pH Adjusters

Coolants often use chemicals like amines or borates to maintain a stable pH. These substances can make the coolant more alkaline, which may upset your skin’s natural balance and cause irritation.

Corrosion Inhibitors

These additives protect metal parts from rust but can irritate the skin. Sodium nitrite and other inhibitors may cause dryness or rashes, especially if you handle the coolant without protection.

Contaminants

Even if the coolant isn’t harmful, contamination can make it dangerous. Over time, tramp oils, dirt, and bacteria can build up in the coolant, introducing additional irritants. Regular testing and cleaning are essential to avoid these issues.

Protective Measures Machinists Should Take

Skin irritation from CNC coolants can be prevented with the proper precautions. These simple steps can help keep your skin safe and healthy while working.

Wear Protective Gear

Always wear gloves when handling CNC coolants. Nitrile gloves are better than latex gloves at resisting chemicals. Long sleeves and aprons add extra protection for your arms and body.

Wash Your Skin Regularly

After handling coolants, wash your hands and any exposed skin with soap and water. This removes any residue that might irritate your skin. Avoid harsh soaps, as they can worsen dryness.

Apply Barrier Creams

Barrier creams help form a protective layer between the skin and the coolant. They’re easy to apply and reduce the chance of irritation. For the best results, use creams designed for industrial use.

Keep Coolants Clean

Dirty coolants are more likely to irritate. Test and filter your coolant regularly to remove contaminants like tramp oil and bacteria. Replace old coolant as needed to maintain its quality.

Use Proper Ventilation

Ensure your workspace is well-ventilated. This reduces the chance of coolant mist settling on your skin or inhaling them. Use local exhaust systems to keep the air clean.

Limit Direct Contact

Try to minimize the number of times your skin touches the coolant. Whenever possible, use tools or equipment to handle parts instead of your hands.

Monitor Your Skin

Pay attention to how your skin reacts. If you notice redness, itching, or dryness, act quickly. Remove the coolant, apply moisturizer, and consult a doctor if the condition worsens.

Maintaining Coolant Quality to Minimize Health Risks

Maintaining coolant quality is crucial, especially in advanced machining environments where precision is key—whether you’re operating a standard system or a CNC controller machine.Clean and well-maintained coolants are key to reducing skin irritation and other health risks. Over time, coolants can get contaminated with dirt, oils, and bacteria, which can harm your skin.

Here’s how to keep your coolant in top condition:

Test Coolants Regularly

Coolants need regular testing to ensure they’re still safe and effective. Check the pH levels, concentration, and microbial growth. If the pH is too high or too low, or if bacteria are present, it’s time to take action.

Filter and Skim

Use filters and skimmers to remove tramp oils and debris from the coolant. Contaminants can irritate the skin and lower coolant performance. Keeping the coolant clean helps protect your health and extend its life.

Replace Old Coolants

Even with proper care, coolants don’t last forever. Replace them as needed to avoid using a product past its prime. Old coolants often harbor bacteria and fungi that can irritate your skin.

Maintain the Right Concentration

Follow the manufacturer’s guidelines for mixing coolants. If they are too diluted, they won’t work correctly; if they are too concentrated, they can irritate your skin. Hence, always measure carefully when adding or mixing coolants.

Are Skin-Safe Coolant Alternatives Available?

Some skin-safe coolant alternatives are available, which can help reduce the risk of irritation for machinists. These coolants are designed to be less harsh while delivering excellent performance during machining.

To find the best skin-safe coolant, check the product label and look for formulas that are labeled as dermatologically tested or hypoallergenic. Always consult the manufacturer’s guidelines and ask for recommendations if unsure.

Below are some skin-safe coolant alternatives:

Synthetic and Semi-Synthetic Coolants

Synthetic and semi-synthetic coolants are popular options for minimizing skin issues. They often contain fewer oils and additives, making them gentler on the skin. Plus, they’re less likely to grow bacteria and fungi, which can cause further irritation.

Vegetable-Based Coolants

Coolants made from vegetable oils are another skin-friendly option. They are biodegradable, eco-friendly, and free from harsh chemicals like chlorinated additives. These coolants are an excellent choice for machinists with sensitive skin.

Low-pH Coolants

Some coolants are formulated with a neutral or slightly acidic pH to match the natural pH of human skin. Thus, they are less likely to cause dryness or disrupt the skin’s barrier.

Water-Soluble Coolants

Water-soluble coolants are diluted with water, reducing the concentration of potentially irritating chemicals. When maintained properly, they can offer effective cooling and lubrication without being too harsh on the skin.

Conclusion

Skin irritation from CNC coolants is a common problem, but you can avoid it with the proper knowledge and precautions. Harmful chemicals, prolonged exposure, and poor coolant maintenance are the leading causes of irritation. You can protect your skin by identifying these risks. Wearing gloves, using barrier creams, and washing your skin regularly are simple yet effective ways to stay safe. If you’re looking for safer options, skin-friendly coolants like synthetic, vegetable-based, or low-pH formulas are available. These alternatives help protect your skin without compromising machining performance.

Join the growing number of machinists who trust Zintilon today. Whether you’re a small shop or a large CNC manufacturing company, we have the right products and advice to keep you running smoothly.