The ins and outs of eye protection.

Pyramex Rendezvous Safety Glasses

Pyramex Rendezvous Safety Glasses

According to the U.S. Department of Labor, thousands of employees suffer from eye injuries every year, many of these injuries sustained at work, usually from inadequate eye protection. These injuries can result in blindness and cost over $300 million per year in lost production time, medical expenses and worker compensation.

Potential eye hazards can be found in almost every industry. What causes eye injuries? According to the US Department of Labor, 70% of the total eye injuries are caused by falling objects or sparks striking the eye. 3/5 of these objects being smaller than a pin head but were traveling faster than a hand thrown object. 20% of the eye injuries resulted from contact with chemicals.

To prevent eye injuries, you should always wear effective eye protection. There are three types of eye protection: safety glasses, goggles or a face shield. Safety glasses are the most common. They are designed with side protection and can resist an impact up to 150 feet per second.  Safety goggles form a seal around the eyes giving better protection and can come in impact resistant and chemical resistant. Chemical goggles protect the wearer from chemical splashes with hooded or indirect ventilation. Impact goggles have direct ventilation holes and protect against direct impact or large particles. Finally there are face shields which are used in welding and sanding applications. Face shields are a secondary form of protection and must be worn with either safety glasses or goggles.  Which type of eye protection is chosen based on the nature and degree of potential hazard the workplace factors and any OSHA and ANSI requirements.

There are three main types of lenses found in eye safety wear. Glass lenses are not easily scratched and can be used around harsh chemicals. They can also be made into a corrective prescription for those who need it. However, they can also be heavy and uncomfortable to wear. Plastic lenses are lighter weight, are good for protecting against welding splatter and are not likely to fog up on your face. However, they are more likely to scratch when compared to glass. Polycarbonate lenses are light weight, protect against welding splatter and are not likely to fog up like the plastic lenses. However they are the strongest lens and have a greater impact resistance then glass and plastic alone.

Protective eye wear goes through a series of tests to verify that it meets the requirements that have been put into place. This includes testing the frames and the lens for durability like flame or chemical resistance, high impact, high mass impact and high velocity impact. High impact will be marked with Z87+. If they are not rated for high impact they will just Z87. Other markings include a V, which indicates photochromic lenses and S which means the lenses have a special tint usually meant for welding or soldering.

Preventing eye injuries through use of safety glasses, goggles and face shields saves money by avoiding injury costs, lost productivity, insurance costs, lawsuits and possible fines. For the worker it avoids catastrophic injury like blindness, pain, lost wages and medical bills. 50% of workers injure while wearing eye protection thought the eye wear had minimized the damage.

CleanPro® offers a wide variety of safety glasses from Pyramex for your eye protection with a variety of lenses tints and lanyards and cords. Click here for details.

How to choose the right particle counter for your cleanroom.

CleanPro offers a wide selection of particle counters. But how to do you determine if you need a particle counter or what model of particle counter to purchase? In this article we will go over the basics of particle counters and give you the facts to help you determine which one is best for your cleanroom application.

A particle counter is an instrument that detects and counts particles one at a time. There are three main categories of particle counters, aerosol, liquid and solid, but only aerosol particle counters directly relate to cleanrooms, so we will be focusing on them. Aerosol particle counters determine the air quality by counting and sizing the particles in the air. They are mainly used in cleanroom applications. Since cleanrooms have defined particle count limits, aerosol particle counters are used to test and classify the cleanroom to ensure it is up to standard.

Airy Technology 3-Channel Handheld Laser Particle Counter and  Kanomax 3900 Portable Particle Counter

Airy Technology Hand-Held Particle Counter (Left) and Kanomax Portable Particle Counter (Right)

There are two types of aerosol particle counters, optical and condensation. With optical particle counters, the particle passes through a high energy light source, then the amplitude of the light scattered or blocked is measured and the particle is counted. Optical particle counters have several different ways to detect and measure particles. They are light blocking, light scattering, and direct imaging. The light blocking method can detect particles larger than a micrometer in size and is based on the amount of light the particle blocks when passing through the light source. The light scattering method is capable of detecting smaller size particles and is based on the amount of light that is redirected by the particle passing through the light source. Direct imaging uses light emitted by a laser as a source to illuminate the particles passing through and measure the area of the particles, like an automated microscope.

A condensation particle counter counts aerosol particles by first enlarging them and using them as nucleation centers to create droplets in a super saturated gas. Condensation particle counters can detect particles as small as 2nm, which cannot be detected with optical particle counters.

Particle counters come in many different sizes. There is a hand-held form, which is a small self-contained model that is easily transported and used. Hand-held particle counters tend to have a lower flow rate, so they are ideal for cleanroom spot checking and certification of lower volumes of air. Larger portable units have a fixed location and continuously monitor the air 24/7. These portable units have a higher flow rate and are ideal for sampling larger volumes of air.

ISO-14644-1 and US-FED-STD-209E Cleanroom Standards.There are two main things to consider when choosing a particle counter.

The first is the size of the particles that you need to monitor. This is determined by the ISO class of your cleanroom.  Make sure the particle counters you are looking at can measure all the particle sizes that you need to monitor. For example a particle counter can have a size range of 0.3/0.5/5.0 µm.

The second factor is the flow rate capacity of the particle counter. To do this you will need this formula: Vs = 20/Cnm) x 1000. Vs is the minimum single sample volume per location. Cnm is the class limit for the largest considered particle size specified for the class of your cleanroom. 20 is the defined number of particles that could be counted for class of the cleanroom. This calculates the number of liters of air that need to be sampled in your cleanroom. So for example if you want to have a class 4 cleanroom, the largest size particle is 1.0 µm and can have a maximum concentration of 83 particles/ m3 according to the ISO 14644-1 cleanroom standards. Plug it into the formula for Vs=(20/83) x 1000, and Vs=240.96. So we would need to sample 240.96 liters of air. So if we chose a small hand-held particle counter that had a flow rate of 2 liters per meter that would take about 120 minutes or 2 hours to sample the air. So for this example I would recommend finding a larger portable particle counter with a higher flow rate.

CleanPro offers particle counters from both Kanomax and Airy Technology in both hand-held and portable models. Click here to view all our particle counters.

Entering a Cleanroom: Preparation

Matt Britt wearing a bunny/moon/cleanroom suit.

Image via Wikipedia

Cleanrooms are 10,000 times cleaner than a hospital operating room. It takes an incredible amount of technology to achieve and maintain such cleanliness. Huge air filtration systems completely change the air in cleanrooms about 10 times per minute, reducing the changes that there are airborne particles that might harm the product. Keeping the environment clean, however, is only half of the story.

What about the people who work in the cleanrooms? The thousands of people who all wear “bunny suits” to protect products from from human particles such as skin flakes or hairs. A bunny suit is made of unique, non-linting, anti-static fabric and is worn over street clothes. Suiting up is a rather involved process, not to mention that every time you enter and leave a cleanroom you have to repeat the steps below:

  1. Store personal items
  2. Discard any gum, candy, ect.
  3. Remove any makeup with cleanroom soap and water
  4. Take a drink of water to wash away any throat particles
  5. Cover any facial hair with a surgical mask or beard/mustache lint-free cover
  6. Put on a lint-free head cover
  7. Clean shoes with shoe cleaners
  8. Put shoe covers on over shoes
  9. Clean any small, pre-approved items to be taken inside
  10. Pick up booties
  11. Sit on “dirty” side of the bench
  12. Put on one bootie (over shoe cover)
  13. Swing bootied foot to “clean” side of the bench
  14. Put other bootie on on the “dirty” side of the bench
  15. Swing bootied foot to “clean” side of the bench
  16. Enter main gowning room
  17. Set aside badge, pager, any other items to be taken inside
  18. Put on nylon gowning gloves
  19. Obtain bunny suit and belt
  20. Put on the bunny suit without it touching the floor
  21. Put on belt
  22. Tuck bunny suit pant legs into booties
  23. Fasten snaps at top of booties
  24. Attach battery pack to belt
  25. Attach filter unit to belt
  26. Plug filter unit into battery pack
  27. Obtain helmet, safety glasses, and ID badge
  28. Put on helmet
  29. Tuck helmet skirt into bunny suit
  30. Zip up bunny suit at shoulders
  31. Attach helmet hose to filter unit
  32. Tighten knob at back of helmet
  33. Put on ID badge
  34. Put on pager
  35. Put on safety glasses
  36. Obtain disposable scope shield
  37. Remove protective covering from both sides of scope shield
  38. Undo front helmet snaps
  39. Attach face shield to helmet
  40. Re-snap from helmet snaps
  41. Examine attire in mirror
  42. Put on latex gloves
  43. Enter the cleanroom

Now not all cleanrooms will follow this exact regimen, but it does give you an idea of what is involved for employees entering a cleanroom. Each step gets the user “cleaner” without contaminating the next layer.

When leaving a cleanroom these steps are taken in opposite order and each layer is disposed of properly. Suits, helmets, and goggles can be cleaned and reused or disposed of. Gloves are almost always one time use items, same with hairnets, bouffants, beard covers, and shoe covers; all are one time use items.

CleanPro offers a wide range of gowning products from shoe covers to full suits, we can help you keep the integrity of your cleanroom by supplying high quality, dependable cleanroom garments.

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