BYK-1690 SD

PRODUCT IDENTITY

BYK-1690 SD is a commercial formulated mixture, not a chemically pure substance. Its documented chemical description is a blend of paraffin-based mineral oils and polyethers adsorbed on an inorganic carrier. The product belongs to the defoamer and air-release additive category, with its principal positioning as a powder defoamer for minerally bound construction systems.
CAS Number: No single CAS number is assigned here to the complete commercial mixture. Individual ingredients can have their own substance identifiers, but an ingredient number should not be used as though it identified the entire grade.
EC Number: No single European Community number is specified for the complete formulated product. Component inventory identities and the regulatory status of the commercial mixture are separate matters.

Molecular Formula: Not applicable as one fixed formula for this mixture of mineral oils, polyethers, and inorganic carrier material.
Molecular Weight: Not applicable as one exact molecular weight. The organic components include distributions of molecular species, and the carrier is a separate material phase.
The supplied powder should not be described as pure silicon dioxide, a crystalline quartz grade, or a single polyether. The safety description identifies amorphous silicon dioxide among the component information and states that nanoforms are present. These details do not replace the identity of the complete formulated defoamer or establish one particle size for the entire commercial powder.
The grade designation is important for traceability. Other solid defoamers can differ in oil type, carrier, organic content, bulk density, binder compatibility, and incorporation behavior. A similar trade number or the general description powder antifoam is not sufficient evidence of technical equivalence.

SYNONYMS

BYK-1690 SD, BYK 1690 SD, BYK-1690SD, BYK 1690SD, BYK-1690 SD powder defoamer, BYK-1690 SD solid defoamer, BYK-1690 SD powder antifoam, BYK-1690 SD silicone-free defoamer, BYK-1690 SD VOC-free defoamer, BYK-1690 SD hydrocarbon defoamer, BYK-1690 SD mineral oil defoamer, BYK-1690 SD polyether defoamer blend, BYK-1690 SD inorganic carrier defoamer, BYK-1690 SD dry mortar additive, BYK-1690 SD dry-mix defoamer, BYK-1690 SD construction additive, BYK-1690 SD mineral binder defoamer, BYK-1690 SD cement mortar defoamer, BYK-1690 SD gypsum system defoamer, BYK-1690 SD plaster defoamer, BYK-1690 SD tile adhesive defoamer

DESCRIPTION AND COMPOSITION

The inorganic carrier provides a particulate support for the organic foam-control ingredients. This arrangement enables a material whose functional components include oils and polyethers to be handled as a powder. It also explains why the product should not be treated as a neat liquid defoamer or assumed to contain 100% organic active substance.
The relative proportions of mineral oil, polyether, and carrier are not defined in this profile. A calculation based on an assumed oil percentage or an invented active fraction would therefore be inappropriate. The recommended use level refers to the product as supplied, including its carrier, and comparative evaluations should preserve that basis.

Paraffin-based mineral oils are hydrocarbon mixtures rather than one discrete compound. Polyethers likewise can have a distribution of molecular weights and structures. The term polyether does not by itself identify a specific polyethylene glycol grade, a particular block copolymer, or a universal solubility profile. The commercial formulation is the relevant unit for performance assessment.
Silicone-free and silicon-free have different meanings. A silicone-free designation concerns silicone chemistry; it does not exclude an inorganic silicon-containing carrier. The presence of amorphous silicon dioxide is therefore compatible with the product's silicone-free description. Likewise, an inorganic carrier does not make the entire mixture inorganic, because the foam-control package contains organic ingredients.
The product is characterized as VOC-free within its stated technical reporting framework, which gives a value below 1,500 ppm. This terminology should retain its defined scope. It does not establish the absence of every volatile trace constituent under all analytical methods or prove that a finished mortar meets a particular building-emissions certification.

TYPICAL PHYSICAL AND CHEMICAL PROPERTIES

BYK-1690 SD is a white powder with no significant odor described in the safety information. The delivery form is relevant to bag opening, powder feeding, premixing, blend uniformity, and dust control. Color and odor are useful observations but do not independently establish foam-control efficiency or the exact composition of the grade.
The typical bulk density range is 450–650 kg/m³. Bulk density describes powder mass per occupied bulk volume, including voids between particles. It is different from the true density of the solid ingredients and depends on filling, settling, aeration, and compaction. A volumetric feeder should therefore be calibrated with the actual product under representative operating conditions.
Using that typical range, 1 kg of powder occupies approximately 1.54–2.22 L. This conversion is useful for equipment planning but does not replace a measurement on the material being handled. A compacted sample can occupy less volume than an aerated sample of equal mass without any change in chemical composition.

The reported pH is approximately 6 at 20°C for a 1% preparation, measured with a universal indicator method. This is a condition-specific observation on a diluted preparation, not a pH assigned to a dry powder in the absence of water. It does not predict the pH of a cement mortar, which is governed predominantly by the binder and the complete formulation.
The grade disperses readily when a dry formulation is mixed with water, but dispersion must be distinguished from molecular dissolution. The safety description reports water immiscibility. These observations are compatible: the powder can distribute through an aqueous mortar while its organic components remain as a separate, dispersed phase rather than forming a true solution.
A liquid flash point is not applicable to this supplied powder. That does not mean the material cannot burn. Its organic content is combustible, and the safety information identifies dust explosion class St1. Relevant handling assessments must therefore consider airborne dust as well as conventional fire precautions.
No fixed melting point, boiling range, vapor pressure, true particle density, or complete particle-size distribution is assigned here. Such values should not be copied from mineral oil, silica, or a generic polyether and presented as properties of the commercial mixture. Typical descriptive values also should not be substituted for agreed batch acceptance limits.

FOAM CONTROL AND AIR STRUCTURE

Foam is a dispersion of gas in a liquid phase. In a freshly mixed mortar, air can be incorporated mechanically during wetting and agitation, while surface-active formulation ingredients can stabilize the resulting bubbles. The visible foam at the surface is only one part of the problem; smaller bubbles can remain within a viscous paste and later contribute to pores or surface openings.
An effective defoaming phase must reach air-liquid interfaces and destabilize bubble films without becoming so incompatible that it produces unacceptable defects. Oil and polyether combinations can be designed around this balance. For BYK-1690 SD, the exact behavior must be assessed in the actual pore solution, binder environment, and additive package rather than inferred from the properties of an isolated ingredient.
The dry carrier is a delivery mechanism, not evidence that the carrier alone performs the entire foam-control function. When water is introduced and the mortar is mixed, the functional ingredients must become distributed sufficiently to act within the working time. Powder blend uniformity and the wet mixing procedure consequently matter to the observed result.

Visible foam collapse does not establish that a material contains no residual air. Rheology, bubble size, layer thickness, and setting progression influence whether bubbles can move, merge, escape, or remain trapped. A formulation can look smooth in the mixing bucket and still show pinholes after application. Fresh density, air measurements, and hardened sections provide complementary information.
Reducing unwanted air can support a denser and more consistent material, but the relationship between air and performance is not identical for every construction product. Some formulations intentionally use controlled air for workability, low density, or durability. The desired outcome is the specified air structure, not an automatic minimum air-content target applied to all mortars.
In particular, intentionally entrained air can be important to freeze-thaw durability in suitable cementitious materials. A defoamer should not be introduced into such a system without checking the required air content and void characteristics. Compressive strength alone is insufficient to establish that a change in air structure is beneficial for the intended exposure.

DETAILED APPLICATIONS

Tile adhesives
BYK-1690 SD can be evaluated in dry mineral tile adhesives where mixing water and polymeric additives create or stabilize unwanted air. The practical aim is a uniform adhesive bed with appropriate consistency, trowel behavior, and contact with the tile and substrate. A foam-control adjustment should be assessed together with the adhesive's intended water demand and application method.
Useful checks include fresh density, visible bubble content, ridge formation, wetting of the tile back, slip, open time, and final bond performance. Changes in air content can alter the apparent body of an adhesive even when the water level remains fixed. Operators should not compensate automatically by adding more water before the source of the changed consistency has been understood.
Cellulose ethers, redispersible polymer powders, wetting agents, and other additives may influence both air stabilization and workability. The defoamer level should therefore be optimized with the actual adhesive package. A result obtained in a simple cement-water paste does not establish performance in a highly modified tile adhesive, especially after storage of the finished dry blend.

Joint fillers
In mineral joint fillers, unwanted bubbles can interfere with smooth filling and contribute to surface openings during finishing. BYK-1690 SD can be screened to improve foam control while preserving the desired consistency and application window. The evaluation should distinguish cosmetic surface quality from the ability to fill the joint adequately at its intended depth and width.
Test material after the normal mixing and resting sequence, and repeat the observation after remixing where that reflects site practice. Some bubbles become evident only during application or wiping. Consistent comparison requires equivalent water addition, tool movement, substrate condition, and timing rather than an assessment based only on the initial mixing bowl.
For colored formulations, assess shade uniformity, visible spots, and the final texture. The additive should not be described as a pigment dispersant or color stabilizer on the basis of reduced foam. Improved surface appearance can arise from fewer air openings, while pigment wetting and distribution remain separate formulation tasks.

Self-leveling underlayments
Self-leveling underlayments are sensitive to the balance between flow, stability, air release, and setting. A material can spread readily yet leave pinholes if air is introduced during mixing or released from the substrate. BYK-1690 SD can be evaluated as part of the foam-control package, with testing at representative application thickness and substrate conditions.
Record flow diameter, flow retention, fresh density, visible bubble activity, and the hardened surface. Observe the material through the usable application period because initial behavior can differ from behavior near the end of working time. A low-foam mixing result should be confirmed after placement, where surface tension, thickness, and setting influence the final appearance.
Substrate outgassing is a separate source of defects. Air emerging from pores beneath an applied layer may create openings even when the fresh mix contains little entrained air. Compare appropriately prepared and unprepared substrates where relevant, and do not use an excessive defoamer addition to conceal an unresolved priming, moisture, or substrate preparation problem.

Self-leveling overlays
An exposed self-leveling overlay can place greater emphasis on visible surface uniformity than an underlayment that will be covered. BYK-1690 SD should be evaluated for the combined outcome of foam control, smoothness, and compatibility with the selected binder and polymer package. More defoamer is not automatically better if the surface develops localized wetting or finishing defects.
Test the intended finishing procedure and any subsequent coating, sealer, or adhesive system. A visually satisfactory fresh surface may develop openings as bubbles escape, while a hardened surface may behave differently during later treatment. Acceptance should reflect the actual service system rather than a single photograph taken shortly after pouring.
The defoamer does not replace a flow agent, shrinkage-control ingredient, or curing procedure. Those functions can influence surface quality independently. A useful trial keeps them controlled and changes the defoamer level systematically so that the source of any improvement or defect remains clear.

Gypsum-bound and plaster systems
In gypsum-bound materials, air can influence mixing consistency, surface appearance, and the texture produced by tools or casting. BYK-1690 SD is suitable for evaluation in this application class, with attention to the specific gypsum source, water ratio, retarders, accelerators, and polymeric additives. These variables can change both the working time and the persistence of air.
Assess fresh density, wet consistency, application behavior, setting development, and hardened surface quality. Thin finishing layers and thicker fills should not be assumed to release air in the same way. A laboratory sample prepared at one thickness can overlook defects that appear in a deeper application or at a different point in the working period.
Some gypsum products intentionally retain air to achieve a defined density or handling character. In those cases, foam control must preserve the target structure. The additive should not be positioned as a universal strength enhancer or density-increasing agent for every plaster formulation; its contribution should be described through the measured behavior of the selected system.

Mineral renders
Mineral renders combine binder, aggregates, and functional additives in a formulation intended to retain workable consistency during spreading and finishing. Unwanted air may contribute to visible openings or an inconsistent finish. BYK-1690 SD can be screened where a reduction in such defects is needed without compromising the render's intended handling properties.
Evaluation should reproduce mixing energy, rest time, application thickness, and finishing technique. Compare fresh density and tool behavior as well as the dried or hardened surface. A change in apparent creaminess can accompany a change in air content and should be assessed against the practical application target rather than treated automatically as a defect.
For renders designed around a controlled pore structure, confirm water-related performance and relevant exposure properties. Foam control does not independently establish water repellency, vapor permeability, or freeze-thaw resistance. These characteristics depend on the full material design, and a visually improved surface should still meet the required functional tests.

Screeds
In mineral screeds, the relevance of unwanted air depends on binder type, consistency, placement method, and compaction. BYK-1690 SD can be evaluated when air generated during mixing interferes with uniformity or the required surface. The test method should reflect whether the screed is flowing, pumped, manually placed, or mechanically compacted.
Track fresh density, working time, placement behavior, bleeding or segregation, and hardened performance. When pumping is involved, sample both before and after the relevant equipment because the process can change air content. A mixing-vessel result alone may not represent the material actually placed on site.
The additive is not a replacement for compaction, proper aggregate grading, or an appropriate water ratio. Large voids caused by inadequate placement or poor consolidation require process correction. Qualification should establish which defects respond to chemical foam control and which arise from mechanical or substrate-related causes.

Factory-produced dry mortar blends
The powder delivery form allows BYK-1690 SD to be incorporated with other dry components before bagging. For low-level additives, distribution through the blend is a major practical issue. A controlled premix with a suitable portion of the formulation may improve feeding and uniformity where the plant equipment cannot distribute a small direct addition reliably.
The selected blending procedure should limit segregation during discharge, conveying, filling, and transport. Differences in bulk density, particle behavior, and vibration can affect the distribution of a minor ingredient even when the mixer initially produces an acceptable blend. Sampling at different points in a production run is more informative than checking only the first bag.
Factory stability should be connected with end-user performance after storage. Test retained dry blends at relevant intervals and then prepare mortar with the intended water addition. Powder flow alone does not establish retained defoaming performance, while a good initial wet test does not establish that every bag will remain representative after handling and storage.

DOSAGE AND CALCULATION

The recommended orientation range for BYK-1690 SD is 0.05–0.5% as supplied, based on the total formulation. This is a starting range for application testing rather than one universal optimum. A low level can be sufficient in one blend, while a formulation containing more foam-stabilizing ingredients may require a different balance.
For a 1,000 kg total formulation on the chosen calculation basis, this range corresponds to 0.5–5.0 kg of the supplied powder. At 0.1%, the addition is 1.0 kg per 1,000 kg. For a 25 kg total dry formulation, 0.05–0.5% corresponds to 12.5–125 g. These examples use the complete supplied product, not a calculated amount of mineral oil alone.
Define the denominator in the batch instructions. In a factory dry-mix recipe, the total powder formulation is the practical batch basis; any comparison using a water-containing final formulation must state that different basis explicitly. Percentages based on binder only, mixing water only, or an assumed active fraction cannot be substituted without recalculation.
If the total formulation mass includes the additive, reserve its mass within that total when preparing a laboratory recipe. Adding a percentage to an already complete base batch gives a slightly different final concentration. The difference may be small at low levels, but using one consistent convention improves traceability and comparison across trials.
Choose the lowest tested addition that provides the required balance of air control and finished performance with adequate robustness. Evaluate an appropriate series across the recommended range rather than selecting the upper end automatically. Persistent defects at a high level may indicate a compatibility or process issue rather than insufficient defoamer.

INCORPORATION AND PRODUCTION PROCESS

Incorporate BYK-1690 SD with the other powder components of the dry mortar formulation. The purpose is to distribute the additive before the end user adds water, so that each portion of the dry mix can develop a comparable foam-control response. Addition procedures should be documented alongside mixer loading, blend time, discharge method, and sampling practice.
Use accurate weighing equipment for small additions. A minor error can represent a substantial relative change at the lower end of the dosage range. Where manual feeding is used, ensure that the weighed portion reaches the mixer rather than remaining in a transfer vessel, dust hood, or bag fold. Keep containers identified to avoid confusion with other white powders.
A premix can be useful if the main mixer has difficulty distributing the additive at its selected concentration. Select a compatible dry formulation component and establish a reproducible premixing procedure. The premix should be sufficiently uniform to support dosing, and its use should not introduce additional moisture, unapproved ingredients, or a different calculation basis.

During wet preparation, follow the intended powder-to-water addition sequence and mixing energy for the construction product. Record mixer geometry, speed, duration, rest period, and any remixing. These conditions influence how much air is introduced and how effectively the defoamer is distributed. Comparing products under different mixing conditions can obscure the additive's contribution.
Avoid treating easy water dispersion as permission to prepare an uncontrolled stock solution. The grade is a supported defoamer powder, and its components do not simply dissolve into one aqueous phase. A separately prepared slurry can have different stability and distribution behavior. Any such alternative process requires its own compatibility and uniformity evaluation.
Qualification should cover both the immediate mix and the working period. A product that suppresses foam directly after wetting may respond differently after rest, additional mixing, or application through equipment. Use the actual process sequence to determine whether the addition remains effective through placement and finishing.

COMPATIBILITY WITH BINDERS AND ADDITIVES

Mineral binder compatibility is a system property. Cement, gypsum, mixed binders, aggregate fines, and soluble ions create different liquid environments when water is added. BYK-1690 SD is positioned for mineral construction systems, but that broad positioning does not remove the need to test a particular recipe or a change in raw material source.
Water-retention agents and polymeric modifiers can affect air stabilization as well as viscosity. Their influence may depend on grade, addition level, and dissolution behavior. If a formulation begins to foam after a cellulose ether or polymer change, review the entire additive balance rather than assuming that the defoamer batch is the only possible cause.
Dispersing and water-reducing ingredients can also change the way bubbles form and persist. A more fluid mortar may release some bubbles more readily while simultaneously generating or stabilizing others during mixing. Compare flow and air content together, and assess whether changes result from water reduction, altered mixing, or the foam-control package itself.

Intentionally air-entraining ingredients require explicit coordination with the defoamer. A formulation may need some controlled air for workability or durability while still avoiding excessive visible foam. The correct target should be defined before testing. Simply maximizing fresh density can be an unsuitable objective for a product designed around controlled entrainment.
Pigments, hydrophobic agents, fibers, and other minor ingredients can introduce additional interactions. A satisfactory result in an unpigmented laboratory base should be confirmed in the commercial formulation. Where multiple variants are sold, representative testing should include those with the most demanding water demand, additive package, or application conditions.
Compatibility also includes the finished surface. Check for localized defects, unexpected texture, wetting changes, or effects on subsequent treatment. The silicone-free description does not guarantee universal freedom from surface effects, because mineral oil and polyether packages still require an appropriate balance with the surrounding formulation.

PERFORMANCE EVALUATION

A useful evaluation begins with a defined problem: excessive fresh air, unstable density, persistent surface foam, pinholes, or an unacceptable hardened finish. Record the baseline before changing the formulation. This prevents a low-foam visual result from being accepted when it does not resolve the actual product requirement.
Prepare a control and an addition series using the same raw material lots, water content, conditioning temperature, and mixing procedure. Random variation in mixing time or water temperature can make a small dosage effect difficult to interpret. Retain sufficient notes to reproduce the comparison and distinguish a robust response from a favorable one-off result.
Fresh density is a practical indicator of air-related changes when the formulation and water level remain fixed. A rise in density can be consistent with reduced air, but density alone does not describe bubble size or the required void structure. Use an appropriate air measurement or hardened examination when those characteristics matter to the application.

Surface testing should reproduce thickness, substrate preparation, finishing, and observation time. Pinholes can develop after a sample initially appears smooth. Record the surface at relevant stages and, where necessary, examine a cut section to determine whether the issue is primarily at the surface or distributed through the material.
Assess workability and hardened performance alongside foam control. Relevant checks may include spread, sag, open time, setting, adhesion, compressive or flexural behavior, and application-specific water or durability properties. Select the tests required by the product rather than claiming that one foam test predicts every construction performance measure.
Include storage and processing variation before approving the final level. Repeat selected trials with aged dry blend, representative raw material variation, or a practical range of mixing energy. A formulation intended for site mixing should tolerate the reasonable variation expected in that use while remaining within its declared application instructions.

QUALITY CONTROL AND SCALE-UP

Incoming quality control should confirm the exact grade, batch identification, packaging integrity, and the documentation agreed for supply. Visual inspection can reveal moisture ingress, unusual clumps, contamination, or a marked departure from the expected powder condition. Such observations should be investigated before the material is introduced into a production blend.
Bulk density is a useful handling parameter, but its measurement method must be defined. Loose-filled and tapped measurements are not interchangeable. A difference caused by sample aeration or compaction should not be interpreted automatically as a change in composition. For volumetric equipment, feeder performance may be more relevant than an isolated laboratory bulk-density result.
Do not invent a particle-size limit, moisture specification, or organic active-content value where none has been agreed. If one of these properties is important to a particular process, establish a suitable method and obtain the necessary product-specific information. The existence of nanoform information does not provide a complete commercial powder particle-size specification.
An application control can complement physical checks. A standardized mortar test using controlled raw materials and mixing conditions can track foam response, fresh density, and surface appearance. Reference samples and equipment conditions should be maintained so that the test detects meaningful differences rather than variations in preparation.
Production scale-up should examine distribution and segregation, not only average addition level. Sample across mixer discharge and bag filling when appropriate. A correct total mass in the batch does not guarantee that every package contains a representative share of the defoamer, especially where the additive is used at a low concentration.
Link raw material records to the dry blend and its retained performance samples. This traceability supports investigation of later complaints and helps separate changes in binder, polymer, aggregate moisture, mixing practice, and defoamer distribution. A structured record is more useful than assuming that a visible foam defect has one universal cause.

HANDLING AND STORAGE

Store and transport BYK-1690 SD below 50°C, in dry conditions and suitable closed packaging. The stated shelf life is 18 months in unopened original packaging under the specified conditions. That period should not be extended automatically to containers that have been opened, contaminated, or exposed to moisture or excessive heat.
Protect bags or containers from water, condensation, and damage during handling. Moisture ingress can change powder flow and blend distribution, and may interfere with the quality of the finished dry mortar. Keep opened packaging closed between uses and use a procedure that preserves product identification and prevents cross-contamination with neighboring powders.
Control dust at bag opening, weighing, charging, and cleanup. Suitable local extraction and careful transfer reduce airborne material and improve dosing accuracy. Avoid vigorous tipping from unnecessary height and do not use compressed air to disperse residues into the workplace. Select collection equipment appropriate to the powder and the assessed fire and explosion conditions.
The documented St1 dust explosion classification requires attention where dust clouds can occur. Keep ignition sources controlled and assess static electricity, electrical equipment, dust accumulation, and the protection of enclosed handling systems. The classification does not supply a complete set of explosion-design parameters; equipment decisions may require additional data and a site-specific assessment.
Keep the product away from strong oxidizing agents. It is stable when stored and used as directed, but stability under recommended conditions does not justify exposure to excessive heat or uncontrolled contact with incompatible chemicals. The mixture contains combustible organic material even though it is delivered on an inorganic support.
Inventory rotation should follow the recorded batch and shelf-life information. If caking, discoloration, contamination, or altered application performance is observed, investigate the storage and handling history. Do not apply the warming procedure used for a different liquid additive or assume that adding water can restore a compromised powder to its original condition.

HEALTH INFORMATION AND EXPOSURE CONTROL

The European safety information dated January 2025 does not classify BYK-1690 SD as a hazardous mixture under the applicable classification system and does not require hazard pictograms or a signal word. This describes the supplied mixture's classification status. It should not be expanded into a claim that dust exposure is desirable or that normal workplace controls are unnecessary.
The product contains nanoforms, with amorphous silicon dioxide identified in the component description. This is distinct from a declaration that the grade consists of crystalline quartz. It also does not mean that every visible powder particle is an isolated nanoscale particle. Dust behavior and exposure depend on the handled material, agglomeration, process conditions, and the fraction that becomes airborne.
Use suitable eye protection, protective work clothing, and gloves selected for the handling task. Nitrile gloves are identified in the safety guidance, but practical selection should also consider fit, duration, mechanical wear, and any other substances being handled. Remove contamination before eating or drinking and maintain normal industrial hygiene.
Ventilation should control dust at its source. Where the actual task or exposure assessment requires respiratory protection, select an appropriate particulate protection system within the workplace program. The absence of a routine respirator requirement under ordinary controlled use does not remove the need to assess unusual dust generation, maintenance, or spill cleanup.
The hazards of the finished dry mortar can differ substantially from those of the additive. Cementitious formulations may introduce alkaline exposure and other component-related hazards. Handling instructions for the complete construction product must therefore be based on that product's composition and use, rather than copied from the defoamer alone.

FIRST AID

For inhalation of dust, move the affected person to fresh air and keep them comfortable. Seek medical advice if symptoms persist or if there is breathing difficulty. An unconscious person requires immediate emergency assistance; protect the airway and use an appropriate recovery position where suitable while awaiting professional help.
For eye contact, rinse cautiously with clean water and remove contact lenses if present and easy to remove. Avoid rubbing the eye because particles can cause additional discomfort. Obtain medical assessment if irritation persists or if symptoms suggest an injury. Do not delay care for a significant eye exposure simply because the mixture is not classified as hazardous.
For skin contamination, remove the powder and wash the affected area with soap and water. Change contaminated clothing where needed. Persistent discomfort or an unusual skin reaction should be medically assessed. Skin contact with a wet cement-containing mortar requires the precautions relevant to that alkaline formulation rather than the additive's classification alone.
If swallowed, rinse the mouth, keep the airway clear, and seek medical advice if symptoms occur or the exposure is significant. Do not give milk or alcoholic drinks, and never give anything by mouth to an unconscious person. Avoid actions that could cause choking or aspiration, and provide the product identity to medical personnel.
First-aid arrangements should cover both powder handling and the wet construction mixture. Accessible washing facilities, clear product identification, and trained responders help ensure that the appropriate information is available promptly. Treatment decisions should follow the circumstances of the exposure and professional medical advice.

FIRE, SPILLS, AND TRANSPORT

The product contains combustible organic ingredients, and airborne dust may form an explosive mixture with air. In a fire, use extinguishing measures suitable for the surrounding conditions; foam, dry chemical, and carbon dioxide are identified as suitable media. A high-volume water jet is unsuitable. Firefighters should use appropriate protective equipment and respiratory protection for the incident.
For a powder spill, avoid generating dust and keep unprotected personnel away from the affected handling area. Collect the material using a controlled method and place it in suitable closed containers. Select a vacuum system only if it is appropriate to the assessed dust and explosion hazard. Do not wash spilled product into drains or surface water.
Clean residues without spreading them to other powders or production equipment. Material collected from a contaminated floor should not be returned automatically to the supply container or a saleable mortar batch. Evaluate rework through a defined procedure that accounts for contamination, traceability, and blend quality.
The documented transport status is not regulated as dangerous goods under ADR, RID, IMDG, and IATA. No dangerous-goods UN number or packing group is assigned on that basis. This transport status does not remove the storage temperature requirement, moisture protection, packaging integrity, or the workplace controls needed during loading and discharge.
Transport and classification information should be checked against current documentation for the actual shipment. A finished mortar containing the additive requires its own assessment. Its transport or workplace status cannot be inferred solely from the status of this minor ingredient.

ENVIRONMENTAL AND REGULATORY CONSIDERATIONS

Prevent uncontrolled release of the powder, organic constituents, and contaminated washings to drains, soil, or water. The absence of a hazardous-mixture classification is not a discharge authorization. Collect residues and packaging through the applicable waste-management arrangements, taking account of contamination and the other ingredients present.
No product-specific ready-biodegradability claim is established here. A mixture containing inorganic carrier and organic ingredients should not be labeled completely biodegradable solely because one component may degrade. Environmental performance claims require a defined test or assessment and should distinguish the supplied additive from the cured construction material.
The VOC-free description in technical information is accompanied by a threshold below 1,500 ppm. A separate dated composition declaration also describes no VOC when calculated under Directive 2004/42/EC. These are defined reporting statements, not a universal zero-emission guarantee. Building-emissions requirements generally concern the finished material under specified conditions and need their own verification.
Inventory and registration statements relate to the components, supply route, jurisdiction, and date of the declaration. A mixture does not acquire one universal substance registration merely because its trade name appears in a supply document. Confirm the relevant market status for the intended activity and obtain current documentation where a contractual requirement depends on it.
Declarations concerning substances not intentionally added should retain that qualification. They should not be rewritten as proof of absolute absence or as a guarantee that every possible trace impurity has been routinely measured. Customer requirements for restricted substances, detection limits, and reporting dates should be resolved through specific current documentation.
No blanket food-contact, drinking-water, medical, or cosmetic authorization follows from the product's silicone-free or VOC-free description. Construction-product performance and emissions classifications likewise apply through defined assessment of the finished system. Regulatory statements should reflect the intended use rather than being extended to unrelated applications.

PRACTICAL PROBLEMS AND SOLUTIONS

Foam persists after wet mixing
Confirm that the correct amount was calculated on the total formulation and distributed through the dry blend. Review the mixing procedure, water level, and foam-stabilizing additives. Run a controlled dosage series before deciding whether the issue is insufficient addition, poor distribution, or incompatibility with the formulation.

Fresh density varies between bags
Investigate dry blend uniformity, segregation during discharge and transport, weighing accuracy, and site mixing. Compare samples from different parts of a production run using one standardized wet preparation. An average batch addition can be correct while individual packages are not representative.

Pinholes remain despite little visible foam
Assess internal air, application thickness, substrate outgassing, rest time, and setting progression. A defoamer cannot correct every source of gas emerging through a fresh layer. Compare prepared substrates and representative placement conditions before increasing the additive concentration.

Workability changes after air reduction
Measure flow or consistency and fresh density at a fixed water level. Air contributes to the apparent body of many mortars, so removing it can change handling. Rebalance the formulation through controlled trials rather than restoring the old feel with an undocumented water increase.

Surface defects appear at higher dosage
Review compatibility and consider a lower level within the evaluated range. More foam-control material can change surface behavior without providing a useful additional air reduction. Check blending and wet mixing so that a local concentration problem is not mistaken for a need to change the whole recipe.

Performance declines after dry-blend storage
Review packaging, humidity, heat exposure, caking, and the stability of the complete additive package. Compare fresh and aged blends using the same mixing protocol. A change in storage performance may involve the binder or polymer system as well as the defoamer.

Powder feeds inconsistently
Check aeration, bulk-density variation, feeder calibration, bridging, and moisture contamination. Use gravimetric control where practical and ensure that extraction does not remove a disproportionate fraction of the weighed addition. Do not assume that a fixed feeder volume always represents the same mass.

Required intentional air is reduced too far
Return to the specified air-content and durability targets and coordinate the defoamer with any air-entraining ingredient. Verify the relevant fresh and hardened properties. Maximum density is not the correct acceptance criterion for every construction system.

FREQUENTLY ASKED QUESTIONS

What is BYK-1690 SD?
It is a supported powder defoamer containing paraffin-based mineral oils and polyethers for mineral binder construction formulations.

Is it a pure chemical substance?
No. It is a formulated mixture with an inorganic carrier.

Does the complete product have one CAS number?
No single CAS number is assigned here to the complete commercial mixture.

Can it be identified as pure silicon dioxide?
No. Silicon dioxide carrier information does not replace the identity of the full mineral oil and polyether defoamer blend.

Does it have one molecular formula or molecular weight?
No. A fixed formula and exact molecular weight are not applicable to the complete mixture.

Is it silicone-free?
Yes. Silicone-free does not mean silicon-free and is compatible with an inorganic silicon-containing carrier.

Is it mineral oil-free?
No. Paraffin-based mineral oils are part of its documented composition.

What is its delivery form?
It is supplied as a white powder.

What is the typical bulk density?
The typical range is 450–650 kg/m³; the measured value depends on powder filling and compaction conditions.

Does bulk density equal true particle density?
No. Bulk density includes voids between particles and is a separate handling property.

Does the powder dissolve completely in water?
It disperses readily during wet mixing, but dispersion is different from molecular dissolution and the product is described as water-immiscible.

What is the recommended starting dosage?
The orientation range is 0.05–0.5% as supplied, based on the total formulation.

How much is 0.1% in a 1,000 kg formulation?
It is 1.0 kg of the supplied powder on that calculation basis.

Is the dosage based on an assumed organic active content?
No. Use the supplied powder mass, including its carrier, unless a separately justified calculation is specified.

When should it be incorporated?
Blend it with the other powder components of the dry mortar formulation.

Can a premix help distribution?
Yes. A qualified premix can help low-level dosing where the main blending equipment does not distribute the direct addition reliably.

Is it used in tile adhesives?
It is recommended for evaluation in mineral tile adhesive formulations with the complete additive package.

Is it used in joint fillers?
Yes. Foam control and final joint appearance should be assessed under representative mixing and finishing conditions.

Can it be used in self-leveling compounds?
Yes. Evaluate air control together with flow, setting, substrate behavior, and the hardened surface.

Is it relevant to gypsum-bound systems?
Yes. Confirm compatibility and the required density and application properties in the actual gypsum formulation.

Can it replace a water reducer?
No. Foam control and water reduction are different functions, even when both influence fresh consistency.

Does it guarantee higher strength?
No. Any strength benefit must be measured in the complete material and considered alongside the required air structure.

Should every formulation be made as air-free as possible?
No. Some products require controlled air for workability, density, or durability.

Can it interfere with intentional air entrainment?
It can change the air balance, so air-content and durability requirements must be checked.

What is the storage temperature limit?
Store and transport the product below 50°C and protect it from moisture.

What is the stated unopened shelf life?
The stated period is 18 months in unopened original packaging under the specified conditions.

Is the product classified as a hazardous mixture in the European safety information?
The January 2025 European safety information does not classify it as a hazardous mixture, while still identifying relevant dust-handling precautions.

Can the dust present an explosion hazard?
Yes. The documented dust explosion class is St1, and suitable handling and equipment controls are required where dust clouds can form.

Is it regulated as dangerous goods for transport?
The documented status is not regulated as dangerous goods under ADR, RID, IMDG, and IATA.

Does VOC-free mean a finished mortar has an emissions certification?
No. A finished-product emissions claim requires assessment under the relevant test and certification conditions.

TECHNICAL SUMMARY AND SUPPLY DISCUSSION

BYK-1690 SD provides a powder route for introducing a mineral oil and polyether foam-control package into dry mineral construction formulations. The carrier-supported structure is central to its handling and identity: the product is neither a neat oil nor a pure inorganic powder. Its performance is established through the way the complete grade becomes distributed during blending, wet mixing, placement, and the available working period.
The main application field includes tile adhesives, joint fillers, leveling compounds, gypsum-bound systems, mineral renders, and screeds. In each case, the formulation objective should be defined through fresh and hardened properties. Reduced visible foam is useful when it contributes to the required density, surface quality, application behavior, and service performance without disrupting intentional air or introducing compatibility problems.
A technically sound trial uses the supplied powder on the total-formulation basis, compares a dosage series with a controlled reference, and preserves mixing and water conditions. Measurements should extend beyond the mixing vessel to application and hardening. Where storage, pumping, bag segregation, or substrate outgassing matter, the qualification should include those conditions rather than relying on one immediate laboratory observation.

Powder handling deserves the same attention as formulation design. Maintain dry storage, observe the below-50°C storage and transport limit, and use the stated 18-month unopened shelf life within its conditions. The absence of a hazardous-mixture classification does not remove the combustible dust considerations associated with St1 behavior or the need for appropriate dust extraction and industrial hygiene.
For a technical discussion with Ataman Chemicals, provide the binder type, complete additive package, water ratio, mixing method, required air or density target, and the observed defect. Information about the application thickness, substrate, working time, storage interval, and relevant finished-product requirements helps focus sample testing. Current documentation and agreed specifications should support any additional regulatory, packaging, or quality requirements.

The practical value of BYK-1690 SD lies in reproducible control of unwanted foam within a defined construction formulation. Correct identity, accurate low-level dosing, uniform powder distribution, and realistic application testing provide the basis for that result. A successful selection combines foam control with the full performance requirements of the dry mortar and its intended use.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com