UK Silver Price
17th April 2018



  HT5 Silver Solder Flux



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

Product description and usages; A white powder suitable for brazing similar or dissimilar parent metals (except aluminium) in conjuncyion with silver solders with a melting point up to 900 degC.

Product Codes

HT5 Flux Powder..




Most important Hazard

R20/21 Harmful by inhalation and ingestion

R36/38 Irritating to eyes and skin
R62/63 Possible risk of impaired fertility or harm to an unborn child.

Potential Acute Health Effects

Inhalation Irritation, coughing, sore throat
Eye Contact Smarting, soreness, irritation
Skin Contact Itching, stinging, sore on cuts
Ingestion Excessive saliva, nausea, vomiting.
Potential Chronic Health Effects Fluorine poisoning
Environmental Hazard Not Available

The main hazards associated with these fluxes are from it's use during the brazing operation. On heating fumes will be produced the volume of which will increase on overheating. These fumes may cause irritation to the eyes, nose and throat.

Irritation on skin may occur on contact with broken skin.


SUBSTANCE CAS No. EINECS No Applicable 'R/ Phases % Cocentration
Potassium Tetraborate 1332-77-0 215-575-5 Xn, R62, Perr.Cat3 25 - 50


16871-90-2 240-896-2 T R23/24/25 50 - 100

Inhalation Treat for shock
Ingestion Administer large volumes of milk or caicium gluconate. Treat for shock and transfer to hospital stating "suspected fluorine poisoning"
Eye Contact S26 Irrigate thoroughly with water and seek medical advice.
Skin Contact Wash thororoughly with water.

Material is not combustible. Fluorine bearing fumes may be evolved. Wear breathing apparatus.

Personal Precautions See Section 8
Environmental Precautions Treat with slaked lime
Clean up methods As appropriate

Storage S2 Keep out of reach of children
S13 Keep away from all foodstuffs


UK Occupational Exposure Standards are: 
Fume                                       Long Term                                                               Short Term 
                                       8-hour TWA* Value 15 minute Value 
Hydrogen Fluoride (as F)            1.5mg/m3                                                                - 2.5mg/m3 
Fluoride (as Fluorine)                 2.5mg/m3 - 

* Time Weighted Average 
Avoid exposure to fume with good ventilation or local extraction. If a risk of inhalation exists, personal 
respiratory protection should be worn. Safety glasses should be worn as well as impervious gloves to 
prevent skin contact. Wash hands after using this material. The use of protective clothing is recommended 


  • Personal Protection Wear Suitable hand protection

Wear Goggles and overalls
Ensure adequate ventilation
S20/21 Do not eat drink or smoke when using
S22 Do not inhale dust
S23 Do not inhale fumes
S45 in case of accident or feeling unwell seek medical advice
Exposure Limits HF TLV 2mg/cubic metre
BF TLV 3mg/cubic metre.

State Solid Powder
Melting Point 550 deg C
Appearance White
pH 9 of aqueous paste.
Boiling Point Not Available
Vapour Pressure Not Available
Explosive Risks Not Applicable
Flammability Risks Not Applicable
Solubility partly soluble in water.

Containers of powder left open once the seals are broken may absorb moisture and become lumpy. Pastes 
are water based and, whilst stable, will lose water by evaporation if left open. Avoid contact with acids and 
strong oxidising agents. 
No other adverse reactions are known

Inhalation Not Available
Ingestion TOXIC
Eye Contact Not known
Skin Contact Not known
Target Organs Not known
Chronic Effects Non known
Carcinogenic Effects None
Mutagenic Effects None
Teratogenic Effects Not available
Narcosis Not available

Toxicological data for these preparations: LD50(oral - rat) > 200mg/kg. 
Classified as moderately irritating, according to Draize skin test. 


Likely to be harmful to all species of animal life. As far as is known no other threat is posed to the 


Waste must be disposed of in accordance with Environmental Protection Act and Integrated Pollution Act. Seek advice from a licensed contractor.

No special precautions

Labeled Harmful

Material classification: 
Risk Phrases: 
20/22 Harmful by inhalation and if swallowed. 
36/38 Irritating to eyes and skin. 
Safety Phrases: 
2 Keep out of reach of children. 
13 Keep away from food, drink and animal feed stuffs. 
20/21 When using do not eat, drink or smoke. 
22/23 Do not breathe dust or fumes. 
26 In case of eye contact, rinse immediately with water and seek medical advice. 
45 In case of feeling unwell seek medical attention. 


References Not Available

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