UK Silver Price
13th July 2018



  HT5 Silver Solder Flux


HT5 Flux Powder Safety Data Sheet REVISION 01 28.04.18.


1.1 Product identifier; HT5 Flux Powder..

1.2 Product description and usages; A white powder or paste suitable for brazing similar or dissimilar parent metal (except aluminium) in conjunction with silver solders with a melting point below 900 degC.

1.3 Details of the supplier.
CuP Alloys (Metal Joining) Ltd
Unit 36 Matrix Business Centre
Nobel Way
S25 3QB
Phone No 01909 547248
Fax No. 01909 547001

Contacts Shaun Meakin, Glen Farrell. Email



2.1 Classification of material.

Classification acording to regulation (EC) No. 1272/2008.

CLP classification.

GHS06: Health Hazard.

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Acute Tox 3: H301 Toxic if swallowed. H311 Toxic if in contact with skin. H331 Toxic if inhaled.


GHS08; Health Hazard.


Repr.2; H361d. Suspected of damaging unborn child.
Classification according to Directive 67/548/EEC or 1999/45/EC as amended;
DPD classification;
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T: Toxic.
R23/24/25 Toxic by inhalation, skin contact and if swallowed.
Xn harmful.
R63;  Possible risk to unborn child.
Hazard Summary;
PHYSICAL HAZARDS;                                      Not classified for physical hazards.
HEALTH HAZARDS;                                          As supplied, the product is harmful by ingestion and will be irritating to the eyes. Skin contact may cause moderate                                                                             irritation. If the skin is broken immediate irritation will occur on contact.
ENVIRONMENTAL HAZARDS;                         Not classified for hazards to the environment.
SPECIFIC HAZARDS;                                       The main hazards associated with this product are from it's use. Fumes will be produced on heating. Fumes may                                                                               include hydrogen flouride and boron triflouride which can cause irritation to the nose eyes and throat.To minimise                                                                               fume always use this product with brazing materials with a maximun liquidus temperature of 900 degreesC.                                                                                         Severe long term exposure to fumes may cause fluorosis. In acute cases there is a danger of pulmonary oemeda                                                                               but this could also be a cause of inhalation of metal fume, met oxide fume or torch gases.
MAIN SYMPTOMS;                                           Irritation of eyes, nose, throat and mucus membranes.
2.2 Label Elements.
Label according to Regulation (EC) 1272/2008.

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CPL SIGNAL WORD;                                             Danger..
Hazard determining components of labeling;         Dipotassium hexafluorosilicate..
                                                                                Potassium tetraborate.
H301, H311 and H331 Toxic if swallowed, in ctact with skin or inhaled.
H361d Suspected of damaging fertilityn or the unborn child.
P280 Wear protective gloves/protective clothing/protective eyewear/face protection.
P281 Ues personal protection equipment as required.
P301+P310 IF SWALLOWED Call a POISON CENTRE / Doctor if you feel unwell.
P361 Remone innediately all contaminated clothing..
P405 Store locked up.
P501 Dispose of container in accordance with loca/regiona/international regulations.
OTHER HAZARDS Not a PBT or uPvB mixture or substance.


3.2 General mixture information.

SUBSTANCE CAS No. EINECS No Applicable 'R/ Phases % Cocentration
Dipotassium hexafluororsilicate 167871-90-2 240-896-2

Acute Tox 3 H301, H311, H331


Potasssium tetraborate 12045-78-2 215-575-5

Repr.2, H361d

Xn, R63, Repr, Cat3

For the listed ingredients the identity and/or exact percentages are being withheld as a trade secret.        


General information; Get medical attention if any discomfort develops.Seek medical attention for all burns regardless of how minor they may appear. Take a copy of this data sheet to show the doctor.

4.1 Description of first aid measures;

AFTER INHALATION; Move to fresh air if breathing is difficult. If breathing has stopped perform artificial respiration and seek immediate medical assistance.

AFTER SKIN CONTACT; Wash the skin thoroughly with soap and water. For reddened or blistered skin, or thermal burns, obtain medical assistance at once.Ensure all clothing laundered before re-use.

AFTER EYE CONTACT; Dust or fume from this product should be flushed from the eyes with copious amounts of clean, tepid water until transported to a medical facility.Do not allow victim to rub or keep eyes tightly closed. Obtain medical assistance at once.

AFTER SWALLOWING; Rinse out the mouth and then drink plenty of water or milk mixed with chalk. Do not induce vomiting. Immediately seek medical assistance.

4.2 MOST IMPORTANT SYMPTONS AND EFFECTS, BOTH ACUTE AND DELAYED; Nausea. Gastric or intestinal disorders when ingested. Breathing difficulty. Coughing.

4.3 INDICATION OF ANY IMMEDIATE MEDICAL ATTENTION AND SPECIAL TREATMENT NEEDED; Treat symptomatically. Medical supervision for at least 48 hours.


General fire hazards; Material is not combustible. 

5.1 Suitable extinguishing media; CO2, extinguishing powder or water spray. Fight larger fires with water or alcohol resistant foam.

5.2 Special hazards arising from the substance or mixture; Hydrogen-fluoride (HF).

5.3 Advice for firefighters

Special protective equipment Use full protection with breathing aparatus as harmful fumes may be evolved.

Special fire fighting proceedures; N/A.


6.1 Personal Precautions, protective equipment and emergency proceedures.
For non emergency personnel Avoid contact with skin and eyes. Use personal protective equipment during any clean up, gloves, eye protection etc as deemed appropriate to the situation. Avoid inhalation of dust.

For emergency responders N/A.

6.2 Environmental precautions; If product is likely to entere sewerage system or watercourse, inform neccessary authorities. Dispose of all collected product/absorbant material as instructed in section 13.

6.3 Methods and material for containment and cleaning up; Scrape up as much of any spill as possible and place in a suitable container for disposal. Wash contaminated area thoroughly with soap and water.

6.4 Reference to other sections; For safe handling see section 7. Foer personal protection see section 8. For waste disposal see section 13.

7.1 Precautions for safe handling; Use product only in well ventilated area and do not inhale fumes created during it's use. Avoid contact with skin and eyes. Do not eat, drink, smoke or apply cosmetics whilst using this product. Keep away from food, drink and animal feedstuffs. Keep out of reach of children. Wash habds thoroughly with soap and water after handling and after any skin contact. Observe good industrial hygene practices.

7.2 Conditions for safe storage including incompatables; Sore in cool, dry place. Keep container closed when not in use. Do not freeze.

7.3 Specific end uses; No further relevany information available.


8.1 Control parameters.

Components with limit values that require monitoring at the workplace; The product does bnot contain any relevant quantities of materials with critical values needing monitoring at the workplace.

Advisory/derived limits.

Element Limit type Value

Dipotassium hexafluorosilicate

CAS 16871-90-2

DNEL (Inhalative) 2.5mg/m3 (worker) (for short & long term systemic & local effects)

Dipotassium hexafluorosilicate:

CAS 16871-90-2


0.9mg/l (fresh water).

0.9mg/l (sea water).

Advisory/derived limits

Element Long term (8 hour) TWA value Short term (15min) TWA value

Fluoride (inorganic as F)

(Cas 16984-48-8

2.5mg/m3              -

Hydrogen Fluoride (as F)

(CAS 7664-39-3

1.5mg/m3 2,5mg/m3


* Time Weighted Average 

Biological limit values; No biological exposure limits are noted for the ingredient/s.

Recommended monitoring proceedures; Follow standard monitoring proceedures;

8.2 Exposure controls.

Appropriate engineering controls; Avoid exposure to fume by using good local extraction or natural ventilation. Local extraction systems should be tested on installation and checked at regular intervals to ensure adequate capture of fume.

Individual protection methods such as personal protection equipment.

General information; If risk of fume inhalation exhists during heating personal respiratry equipment should be worn.

Eye/face protection; It is recommended that safety glasses are worn when handling and using this product.

Skin/hand protection; Where regular contact with skin cannot be avoided suitable gloves should be worn. Also where contact with molten flux or fume may occur, Glove supplier should eb able to advise on suitable gloves. Show them this data sheet. 

Other; None.

Respiratory protection; If risk of inhalation exchists personal respiratory equipment should be worn.

Thermal hazards; The product will fume slightly on heating and fuming will increase with overheating. These fumes may include hydrogen fluoride and boron trifluoride which ccan cause irritation to the eyes, nose and throat.

Hygiene measures; Wash hands thoroughly after using this product.

Environmental exposure controls; See section 6.


9.1 Information on the basic physical and chemcal properties.

Appearance; White powder.

Physical state; Solid.

Colour; White.

Odour; Odorless.

Odour threshold; Product has no odor so not aplicable.

pH Value; Not applicable.

Melting range; 500-1050 DegC.

Boiling point; No data available.

Flash point; No data available.

Flammability; No data available.

Evaporation rate; Not applicable.

Vapour pressure; Not applicable.

Vapour density; Not applicable.

Relative density; Not applicable.

Solubility; Partialy soluble.

Partition co-efficient; Not applicable.

Decomposition temperature; Not applicable.

Viscosity; Not applicable.

Explosive properties; Product does not present an explosive hazard.

Oxidising properties; Not applicable.

9.2 Other information No further relevant information available.

Bulk density; Not applicable.

VOC (weight %) Not applicable.



10.1 Reactivity; Product is stable.

10.2 Chemical stability; Stable in normal conditions.

10.3 Possibility of hazardous reactions; Avoid contact with acids and strong oxidising agents.

Hazardous decomposition products; Hydrogen fluoride.

10.4 Conditions to avoid; Avoid contact with acids and strong oxidising agents.

10.5 Incompatible materials; Avoid contact with acids and strong oxidising agents.


General information; Occupational exposure to then substance or mixture may cause advers effects.

Information on likely routes of exposure

Inhalation Fumes may contain hydrogen fluoride and boron triflouride which can cause irritation to eyes, nose and throat.

Ingestion; Ingestion may cause irritation and malaise.

Skin contact; Skin contact may cauase moderate irritation. However if the skin is broken immediate irritation will occur on contact.

Eye Contact; Not likely given nature of the product.


11.1 Information on toxicological effects; Potassium tetraborate has been classified as a reprodutive toxin category 3, Repr, Cat 3 and presents possible risks of imoaired fertility and risks of harm to the unborn child.

Values relevant for Classification Test            Result  

Dipotassium hexafluorosilicate

(CAS 16871-90-2

LD50 (oral-rat)

LC50/4h (inhalative-rat)



Potassium tetraborate

(CAS 12045-78-2)

LD50 (oral-rat) 3500-4100mg/kg

Acute toxicity; Not classified.

Skin corrosion/irritation; Not classified.

Respiratory sensitisation; When heated fumes are evolved which may cause respiratory tract irritation.

Skin sensitisation; Not classified.

Germ cell mutagenicity; No data available.

CarcinegicityNo data applicable.

Reproductive toxicity; Suspevted of damaging unborn child. Risk of harm to unborn child.

IARC Monographs. Overall Evaluation of Carcinogenicity

Not classified. According to accessed 08.04.13.

Specific organ target toxicity; Not applicable.

Aspiration hazard; Not applicable.

Mixture vs substance information; Not applicable.

Other information; None.


12.1 Toxicity.

Component                         Test                        Method                         Result

Dipotassium hexafluorosilicate







Fish (Dario rerio)  




Potassium tetraborate  

(CAS 12045-75-2)



Daphnia (en bone (B) - daphnia magna straus)  

Fish (on bone (B)-Limanda limanda)




12.2 Persistance and degradability; No further data available.

12.3 Bioaccumulative potential; No further data available.

Partition co-efficient n-octanol/water (log Kow); No further data available.

Bioconcentration factor; Unknown.

12,4 Mobility in soil

Mobility in general; No further data available.

12.5 results of PBT and vPvB assessment; Not applicable.

12.6 Other adverse effects; Water hazard class2 (German regulation) (Self assessment) hazardous for water.


13.1 Waste treatment methods

Residual waste; Must not be disposed of together with household garbage. Must not be allowed to reach sewage system.

Contaminated packaging Not applicable.

EU Waste Code; Not applicable.

Disposal methods/information; Dispose in accordance with local and national regulations. Registered waste contactors should be awareof the composition and data as given in section 2 of this data sheet..

UN 'Model Regulation UN2655 POTASSIUM FLUOROSILICATE, mixture, 6.1, lll

Land transport ADR?RID (cross border).

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14.1 UN number; 2655.

14,2 UN proper shipping name; UN2655 POTASSIUM FLUOROSILICATE mixture.

14.3 Transport hazard class (ES); 6.1 Toxic substance.

14.4 Packing group; lll

14.5 Environmental hazards; Not appliccable.

Tunnel restriction code; E.

Limited Quantities (LQ); 5 kilos.

Transport Catagory; 2

Labels required; 6.1.

14.6 Special precautions for user; Warning. Toxic substance.

Maritime Transport IMDG

As above plus;

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14.7 Transport in bulk according to Annex ll of MARPOL 73/78 and IBC Code; Not applicable.

Air transport ICAO_TI and IATA_DGR

As above.


15.1 Safety, health and environmental regulations/legislations specific for the substance or mixture.

Eu Regulations; Not listed under REACH Article 59(1) Candidate list as currently published by ECHA.

Authorisations; Not listed.

Restrictions on use; No restrictions on use.

Other Eu regulations; Not regulated.

Other regulations; The product is classified and labelled in accordance with Regulation (EC) 1272/2008 (CLP regulation) as amended, and respective national laws implementing EC directives.

National regulations; Not listed.

Substances of very high concern (SVHC) according to REACH article 57; The product is manufactured in a facility where both boric acid CAS 10043-35-3 and sodium tetraborate CAS 1303-96-4 are used in the manufacture of brazing fluxes and therefore then possibility of cross contamination to a level above the maximum impurity levels of both substances of 0.1% cannot be excluded.

Customs clearance Nomenclature;

15.2 Chemical safety assessment; No chemical safety assessment has been carried out.

NB The information contained in this sheet is believed to be accurate, but CuP Alloys (Metal Joining) Ltd assumes no liability for its accuracy or completeness. Final determination of the suitability of a product remains the responsibility of the user.




Copyright CuP Alloys (Metal Joining) Ltd 2018