Chairs & Stools

Why seating is a specification

A chair that does not fit the bench gets replaced, worked around, or blamed for an injury.

Industrial seating fails quietly. Nobody files a report because a stool is two inches too low. The operator perches forward on the front edge, loses the backrest, works with unsupported arms, and eight hours later has a sore back that gets attributed to the job rather than to the chair. Multiply that by a shift and the cost is real, but it never appears on a line item.

The fix is unglamorous: seat height comes from the work surface, base comes from the floor and the task, and the environment decides materials. Those three decisions determine most of the model number. Comfort preferences matter, but they come last, and they matter far less than fit.

What the line covers

BioFit publishes seating across a common platform. Most task series share the same specification: 350 lb capacity, pneumatic seat height adjustment, a fixed 3-1/2 degree rearward seat tilt, backrest tilt and backrest height adjustment, four base choices and three height classes. What changes between series is the seat and backrest, and what changes between environments is the material and the grounding.

Related guides

Work surface height is set by the bench, so the Workbenches & Workstations guide is the companion to this one. For controlled environments generally, see the Cleanroom & Stainless Equipment guide. For standing operations, the Anti-Fatigue & Safety Matting guide covers the other half of the problem. To browse the range, see chairs and stools.

Reading a BioFit model number

Series, base, height class, mobility and environment, in that order.

A BioFit model number is a build sheet. Once you can read it, two quotes that look different often turn out to be the same chair with a different base, and two that look identical turn out to differ on the thing that matters.

The positions

Matching seat height to the work surface

The decision the whole specification hangs on.

BioFit publishes a formula for this, and it is the single most useful thing in the catalog.

Aiming for the midpoint rather than the edge is what makes the chair work for more than one person. A range that only just reaches the required height leaves nothing for a taller or shorter operator, and on a shared bench that is the difference between a chair that fits the shift and one that fits one person.

The height classes

Three classes are published, and the actual range depends on which base you pair them with. The steel base starts higher than the aluminum and composite bases in every class, by an inch at the low class and three inches at the high class.

Thinner seats sit lower

The molded urethane and polypropylene series use a 1.5 in. thick seat rather than 3 in., and their published ranges sit roughly an inch lower as a result. The UniqueU series on a steel base is published at 17 to 21 in. low, 20 to 27 in. medium and 24 to 31 in. high, against 18 to 22, 21 to 28 and 25 to 32 for the upholstered series on the same base. Across the whole line, published seat heights span about 16 to 32 in.

Bases, footrings and footrests

Stability, sweep and where the feet go.

Four bases are published, all five-legged, described as a high-profile design with T-shape construction for strength and cleanability. They differ in diameter and material, and the diameter is a stability and floor-space decision.

How to choose

• Wider is more stable, and takes more floor. The 28.7 in. wide aluminum base resists tipping best, which matters most on tall chairs where the center of gravity is high. It also sweeps a bigger circle, so in a tight cell it collides with bench legs and neighbouring stations.
• The steel base includes a footring. On the other three, a footring is an added line item. If the chair is medium or high class, budget for one from the start.
• Composite resists corrosion. Where washdown or chemicals are present, the reinforced composite base avoids the finish problems a painted steel base eventually has.

Footrings

Any seat height above about 22 in. leaves most people's feet off the floor, and unsupported feet are the fastest route to complaints on a tall stool. Two adjustable footrings are published beyond the fixed 21 in. ring on the steel base: a 20 in. cast aluminum adjustable ring, and a 22 in. oval tube adjustable ring on a polished cast aluminum mount.

Footrests

Where the chair sits at desk height but the operator still cannot reach the floor comfortably, a free-standing adjustable footrest is the answer rather than changing the chair. Published options include FS-1, the chrome FS-1-C, FS-2, and FS-1-K, which is the ESD version. In a static controlled area specify the ESD footrest, since a standard one under the operator's feet sits directly in the path Section Nine is trying to protect. A footrest is also the cheaper fix when one person on a shared bench needs support and everyone else does not.

Casters or glides

BioFit publishes both and no rule for choosing. Here is how to decide.

Three mobility options appear on most configurations here: RC hooded dual-wheel non-marring casters that lock when the seat is unoccupied, HG 2 in. polyamide glides, and RK ESD casters for static control applications. Additional caster and glide codes exist on some series spec sheets, so ask if you need something specific. What the catalog does not give is a rule for choosing, so the rest of this section is our guidance rather than a published specification.

Choosing the series

Seat size, backrest height and material. Everything else is common across the platform.

Because the mechanism, capacity and adjustment are shared, the series choice comes down to three things: how big the seat is, how tall the backrest is, and what both are made of.

Backrest height is a task decision

A tall backrest supports the upper back and is right for long seated work at a fixed station. A short backrest clears the lower back only, and leaves the shoulders free to twist and reach. Neither is better; they suit different jobs.

The sewn seam group is worth understanding. BioFit publishes that using seams minimises compression of the pre-contoured foam during manufacture, which it credits with fuller lines, enhanced form, and chairs that stay comfortable over the long term. Treat it as a comfort and finish upgrade on the strength of what is published, and specify it where one person occupies the chair for a full shift. The four codes vary by seat width and backrest height, so HC is the smaller seat with the tall back and FC the wider seat with the same back.

Molded and specialty series

Stools

Four stool families are carried here. Rexford is a backless round stool with a 16 in. seat and 3.5 in. of high-resilience molded foam. Regent is the same seat with a streamlined 14.5 by 9.5 in. backrest added. Cerex is a backless 14 in. self-skinned urethane stool built for demanding conditions. Aramis is the specialist: vacuum-formed sealed upholstery with foot-activated pneumatic height adjustment, which means hands-free operation where hands are gloved, sterile or full.

Seat controls and arms

What comes standard, and what the upgrades actually buy.

The standard control

Every task series covered here ships with what BioFit calls Task Control Soft Touch: pneumatic seat height adjustment on a soft-touch lever, a fixed 3-1/2 degree rearward seat tilt, backrest tilt adjustment and backrest height adjustment. Height adjustment across these series is pneumatic throughout. BioFit does build fixed-height stools in ranges outside this selection, so if you specifically want a non-adjustable stool, ask rather than assuming.

The standard control covers most production seating. The articulating options earn their cost where one person occupies the chair all day and needs the seat and back set independently, or where the task involves leaning forward for long periods and a fixed rearward tilt fights against them.

Arms

Arms come as XA, meaning none, unless specified. Two published options: ARS adjustable for both height and width with self-skinned urethane pads, and PSAS height adjustable with the same pads. Zephyr models publish their own arm options including an upholstered-pad version.

Upholstery and seat materials

Choose by what gets spilled on it, not by color.

Three upholstery families are published for the standard palette, plus molded materials for the specialty series. BioFit prices upholstery by numbered grade in its own catalog, with lettered grades for the ESD materials, while product listings usually show the collection names rather than the grade. If you are comparing quotes, check the grade as well as the color name.

Note that no stainless steel seating is published in this range. Where the requirement is genuinely stainless, that is a different product category; the answer here for aggressive environments is molded urethane or polypropylene. Customer's Own Material is accepted, with a warranty consequence covered in Section Thirteen.

Static control seating

What makes a chair ESD-safe, and why standard casters defeat it.

An ESD chair is not a normal chair with conductive fabric. The whole point is an unbroken conductive path from the person to the floor, and every joint in that path has to conduct. BioFit's published construction addresses each link.

Which series and how to order

Static control versions are published for the larger-back HC, AM and FC series, the smaller-back HL, FL, EE, BE, ET and BT series, and the molded UU and ArmorSeat series, across all four bases and all three height classes. The suffix is K. ESD casters are also orderable as an RK option on standard models.

Standards

BioFit publishes that its static control seating is tested to ANSI/ESD STM12.1, the standard covering seating resistance measurement, and is intended to support compliance with an ANSI/ESD S20.20 program. Note carefully what that does and does not mean: the chair is one qualified element within a program, not compliance in itself. The floor, the mat, the wrist strap, the footwear and the verification schedule are all part of S20.20, and a qualified chair on an unqualified floor achieves nothing.

Cleanroom seating

Ordered by ISO class, and the class is part of the model number.

Cleanroom seating is published for the Amherst, Elite, Belize, Eton and Bridgeport upholstered series, plus UniqueU molded urethane, ArmorSeat polypropylene and the Cerex stool. Construction is described as using components and materials compatible with the cleanroom environment, with chrome-plated metal parts and vinyl upholstery.

Ordering by class

The ISO class is encoded in the model number suffix. Stocked configurations commonly carry IS08 for ISO Class 8 and IS06 for ISO Class 6, and product listings indicate ratings are available across ISO Class 3 through ISO Class 8 under ISO 14644-1. Specify the class your room is certified to, not the class you think you need.

What is not published

Particle-shedding test data, outgassing data and seam-sealing details do not appear in the published product information, and Federal Standard 209E is named without any class number being assigned to a product. If your qualification process requires particle counts or a 209E equivalence for incoming equipment, request that documentation from the manufacturer before ordering. A guide cannot supply numbers the manufacturer does not publish.

Harsh environment and washdown

Where upholstery has no future.

The harsh environment answer in this line is molded material, not coated fabric. The UniqueU series in molded self-skinned urethane is published as resisting water, chemicals and paint, which is the specific combination that destroys upholstered seating in paint shops, wet processes and chemical handling areas.

ArmorSeat in non-porous polypropylene is the parallel option where the issue is cleanability and hygiene rather than chemical attack. It carries antimicrobial properties and UV inhibitors as standard, and being non-porous there is nothing for contamination to soak into.

The trade is padding. Molded seats are 1.5 in. thick against 3 in. for upholstered, and they are firmer. For a station where someone sits for a full shift, that difference is noticeable, and it is worth pairing a molded chair with a footring so the operator is not carrying weight through the seat edge.

Heavy capacity and continuous use

One model, and the reason it exists.

Capacity across the BioFit line is 350 lb, published consistently on every task series. There is one heavy-capacity model: the Intensive Plus, rated at 500 lb. There is nothing between the two.

Note the warranty difference: the Intensive Plus carries a five-year warranty against the thirteen years published for the rest of the line. That is not a quality signal so much as a duty-cycle one, and it is covered in the next section.

Warranty and what it excludes

Unusually long, with three exclusions worth reading before you order.

BioFit publishes a 13-year warranty against mechanical or structural failure due to defective material or workmanship, under normal multishift use. Pneumatic cylinders, which are the part most likely to fail on a heavily used chair, are covered for the functional lifetime of the chair or stool.

Thirteen years on multishift use is a long warranty for production seating, and it changes the cost comparison against cheaper chairs. A chair replaced every three years costs more over a decade than one that carries a warranty through it, even at several times the purchase price.

Common and costly mistakes

Twelve things that go wrong on seating orders.

1. Not measuring the work surface. Seat height is derived from it. Work surface height minus 12 in. gives the ideal seat height midpoint, and everything else follows.
2. Specifying to the edge of the adjustment range. Aim for the midpoint. A chair that only just reaches the height fits one operator and no one else.
3. Ignoring the mat. Anti-fatigue matting raises the operator relative to the bench. Measure the surface as installed.
4. Forgetting the footring on tall chairs. Above roughly 22 in. of seat height, feet do not reach the floor, and unsupported feet generate complaints faster than anything else.
5. Buying an affixed footring for a shared chair. The footring has to move with the seat. On a multi-operator chair, specify an adjustable ring.
6. Casters where glides belong. Tall chairs, matted stations, grated floors and fixed positions all want glides. A tall chair that rolls as someone sits on it is the main injury risk here.
7. Fabric in a wet, oily or chemical area. It absorbs everything. Choose the material from the contamination, then pick a color.
8. Standard casters on an ESD chair. This silently breaks the grounding path. It applies to replacement casters years later as much as to the original order.
9. Treating an ESD chair as ESD compliance. The chair is one qualified element in an S20.20 program, alongside the floor, footwear and verification schedule.
10. Adding arms without checking bench clearance. Arms stop the chair pulling in to the work surface. Check before ordering a run of them.
11. Specifying a backless stool for all-day seated work. Backless suits short-duration, high-movement tasks. It supports nothing over a shift.
12. Supplying your own upholstery without reading the warranty. COM material is excluded from the 13-year cover.

Frequently asked questions

The questions that come up most often on seating quotes.

Quick-reference tables

Everything above, condensed.

Model number decoder

Seat height by class and base

Molded series with a 1.5 in. seat sit about an inch lower. UniqueU on the steel base is published at 17 to 21 in. low, 20 to 27 in. medium and 24 to 31 in. high.

Specifications common to the task line

Environment to material

Specify-it checklist