Brand Hero

Lakeland Europe Blog

Lakeland Europe Blog Lakeland Europe Blog – Français Lakeland Europe Blog – Deutsch Lakeland Europe Blog – española Lakeland Europe Blog – Italiano Lakeland Europe Blog – Nederlands Lakeland Europe Blog – Polski
 English  Français  Deutsch  española  Italiano  Nederlands  Polski

A detailed guide to ChemMax 1, 2, 3 and 4Plus liquid protective clothing

ChemMax Designed for Protection and Comfort

Finding the right level of protection for each operator and task is a fundamental aspect of a Safety Manager’s remit. With growing recognition of the need to balance protection with comfort, to maximise both productivity and worker well-being, it has become increasingly important to look beyond the basic liquid protective clothing to understand how key aspects of the fabric and design work in the real world.

The level of protection required will vary dependent upon the task being undertaken, the toxicity and nature of the chemical and the type of spray. It is important to distinguish between permeation and penetration of liquid chemicals, two distinct processes explained in the video below:


This distinction is important because garment FABRIC provides protection by minimising PERMEATION through it whilst garment DESIGN and FEATURES provide protection by minimising PENETRATION through possible holes and gaps in the construction of the garment - such as seams, zip fastenings and so on.


Resisting Chemical Permeation

Different fabrics are used to provide protection against permeation of different chemicals. Chemical suits for Type 3 and 4 applications are made with solid, barrier films – in the higher level versions (ChemMax 3, 4Plus and Interceptor) often multiple layers of different and specialist polymer films to resist different types of chemical. (Type 6 garments generally deal with less hazardous chemicals and are constructed with permeable fabrics – not solid barrier films). In general terms fabrics that will resist permeation of more challenging or dangerous chemicals consist of multiple film layers and are consequently hPeavier.

Permeation vs Penetration

Whereas penetration measures chemical in visible volumes (i.e. in volumes than can be visibly identified breaking through the fabric), permeation deals with much smaller volumes, measuring amounts permeated in micrograms (one microgram (µm) is one millionth of a gram). Thus we can draw the following general conclusions (though be aware that this is not ALWAYS the case but can be a useful guide):-

chemical hazards image with chemical suit-banner1. Permeation is more critical for chemicals with high toxicity – those that may have adverse health effects as a result of contamination with very small volumes – one reason why understanding the toxicity of the chemical against which you need protection is vital.

2. Penetration is more critical for those chemicals that primarily have immediate effects on contact with skin - such as corrosive chemicals, acids etc that will cause burns in the area of contact but are not carcinogenic and have no long-term health consequences for other parts of the body. With chemicals such as these the larger penetrating amounts will matter, but the tiny amounts involved in permeation are unlikely to cause major burns and may well not even be noticed. 

So understanding this difference is important in understanding the type of protection needed.


Resistance to permeation against specific chemicals is assessed using the permeation test (EN 6529, or ASTM F739 in North America) which measures permeation rates through the fabric. But beware! The “breakthrough” in this test is not when the chemical first breaks through the fabric and is not an indication of safe-wear time. This is one of the biggest and most common misunderstandings in PPE and if nit understood correctly can result in workers believing they are better protected than they really are.


Resisting Chemical Penetration

A chemical cannot penetrate through the solid barrier film of a suit fabric – there are no holes to penetrate through. It could however penetrate (in considerably larger volumes than if it permeates through the fabric) through any holes or gaps in the garment construction (or through gaps between the garments and other PPE such as gloves, boots or face mask).

Thus whereas fabric choice relates to resistance against permeation of a specific chemical, protection against penetration is dealt with by the garment design and features, such as the use of stitched and taped seams to seal stitch holes, and an effective front fastening to ensure no liquid can pass through the zip.

Resistance to penetration is addressed by the Type 3,4 and 6 whole garment spray tests which assess the effectiveness of the garment design and construction in resisting penetration by different types of spray, aerosol sprays (Type 6), liquid (shower) sprays (Type 4) and liquid jet sprays (Type 3), explained below. However, again Beware! Do not assume that a garment that has passed these tests will prevent ANY penetration. Each of the tests described below does allow some level, defined by a specific calibration method, of penetration and whilst small, this might be important in the case of highly toxic chemicals.


It is important to understand the difference between Type 3 and Type 4 as they represent two different types of protection. Many chemical suits are both Type 3 AND Type 4, yet the majority of applications are Type 4 only. Identifying that an application is Type 4 rather than Type 3 means a more comfortable option such as Lakeland Cool Suits, could be chosen.


Lakeland’s ChemMax protective clothing range is designed to meet the diverse needs of workers, combining Type 3, 4 and 6 liquid chemical protection and Type 5 hazardous dust protection, with considered fabric and design to improve comfort and usability. Different fabrics deliver different levels of protection - the higher the number, the greater the range of chemical barrier.


Testing Suits against liquid penetration

For Type 3, 4 and 6 PPE testing, the test subject wears an absorbent white suit under the PPE to indicate through staining if any of the test liquid penetrates inside the test suit. The subject enters a spray cabin and is sprayed with different forms of spray.

  • Type 3 garments are exposed to a strong jet spray, with liquid blasted at “weak points” in the garment such as seam joins and the zip fastening.

    Type 3 Test graphic


  • Type 4 garments are subject to a shower of the liquid over one minute, whilst the test subject rotates on a turntable and makes a stepping motion. There is no pressure on the garment as there is in the Type 3 test.


Type 4 test graphic



  • Type 6 garments are exposed to a light aerosol spray, with a lower volume of liquid applied than Type 4 - allowing lighter garments of non-barrier fabric to pass.


Type 6 test graphic



  • Type 5 (hazardous dust) garment testing involves a test subject donning the suit and entering a cabin into which sodium chloride dust (salt dust) of various particle sizes is sprayed.


Type 5 test graphic-1


For more information on Type 3,4,5 and 6 testing:


The ChemMax range

ChemMax 1

Designed to provide lightweight and effective Type 3 & 4 protection against a broad range of commonly used chemicals, ChemMax 1 is constructed using polyethylene barrier film laminated to a continuous filament polypropylene non-woven fabric. With stitched and taped seams, double zip and storm flap, cushioned knee-pads and Lakeland’s unique Super-B style pattern – the suit delivers excellent fit and ergonomic superiority compared to other garments.



ChemMax 2

Also delivering Type 3 & 4 protection, ChemMax 2 provides high-performance permeation resistance against a wide range of chemicals while also offering more flexibility and comfort for workers. ChemMax 2’s unique properties include an additional permeation barrier as well as greater mechanical strength – at a lower cost than expensive competitor products.

The ChemMax 2 range features soft, durable and proven Saranex 23P barrier film which offers an equivalent or better permeation barrier than more expensive alternatives for 63% of the chemicals tested; as well as mechanical strength properties that are equal or better, according to most CE measures. Click here for more information on ChemMax 2.  


ChemMax 3

Providing advanced chemical protection for industry, emergency response and law enforcement, ChemMax 3 provides an extensive chemical barrier whilst also being soft, flexible and tough. The multi-layer barrier construction provides protection against a wide range of hazardous chemicals and the co-extruded fabric technology provides a smooth and flexible fabric that is free from the crushing and pitting suffered by adhesive or heat-laminated barrier fabrics.


ChemMax 4 Plus

Developed in Europe by a leading manufacturer of fabrics for military use in protection against chemical warfare agents and fully tested against a full range of CWA, ChemMax 4 Plus delivers high barrier chemical protection in a tough and durable multi-layer fabric. Delivering additional comfort through the use of a fabric that is softer and more flexible than other products with a similar chemical barrier, it enables companies to better manage the issue of balancing comfort and protection.

Both ChemMax 3 and ChemMax 4 are supported by  PermaSURE®, the free, smart-phone app that models permeation rates and provides safe-use times by incorporating, temperature and chemical exposure factors. Based on the known molecular characteristics and behaviour of 4000+ chemicals, PermaSURE provides users with easy access to realistic safe–wear times based on accurate permeation rate modelling, enable selection of the appropriate suit and ensuring safe use and addressing the common misunderstanding and mis-use of permeation test “breakthrough” described above.


ChemMax Design & features

The ChemMax range includes several design innovations to improve both safety and worker comfort. These include:

  • All coveralls have both double zip and storm flap to the front of the garment to provide safe and secure protection
  • All ChemMax coveralls use Lakeland’s 3-point “Super-B” pattern – a unique combination of three key design features resulting in superior freedom of movement, better fit and greater comfort.
  • All ChemMax products are available in a range of styles including encapsulating suits and accessories such as boots, jackets and hoods
  • ChemMax 1 and 3 are available as cool suit designs.



ChemMax in Action

The importance of planning ahead and involving the workforce in the chemical suit assessment process were underlined in 2018 when a petrochemical Benelux-based company  faced a serious problem due to the lack of availability of its usual chemical suits. The main product, methyl diisocyanate, is important in the production of polyurethane (PU) foam which is used to produce everything from seats to safety shoes and is a “behind the scenes” process in the petrochemical industry.

Without proper chemical protection, the company could not go ahead with a major “keystone” shutdown.

The organisation not only needed a garment with the right permeation resistance to the chemicals on-site but one that would also be accepted by the workers. That meant a suit that was both tough enough to meet the physical demands of the application and provided the comfort and flexibility workers require. Plus, of course, the chemical suit had to be available at short notice to ensure the shutdown could proceed as planned. The company chose ChemMax 2 – which not only met both protection and comfort specifications but had also been tested and accepted by workers previously during a Safety Day event.



To achieve the right level of protection for the workforce, Safety Managers need to consider multiple factors. What level of protection is required? What tasks are being undertaken? What are the hazards? How toxic is the chemical or dust?

For more help in finding the correct garment for chemical protection, use the ChemMax Chemical Search page or download the complete database of chemicals tested. Alternatively, get in touch if you need more help.


Download Guide to Chemical Suit Selection


© 2020 Lakeland Inc. All Rights Reserved.