Minimising Silica Exposure Risk

Investing in a Safer Working Environment


In a world first, GRS has carried out extensive research and development to be able to provide the industry with a product that minimises operators exposure to respirable crystalline silica, yet still provides the same high level of casting quality and usability as a traditional based investment powder.

In April 2019 we achieved our goal and have applied for a Patent to cover this new technology.

X-SIL technology investment powder can be used like for like in place of traditional investment powders in terms of usage procedures, water ratios, mixing equipment, furnaces and burnout cycles, casting machines, casting temperatures and downstream processes.


Minimising Silica Exposure Risk


Due to different health and safety regulations worldwide related to the cut off limits of Respirable Crystalline Silica (RCS), the below Hazard classification is required with X-SIL specifically for the United States of America due to the classification of the product.

In the United States if a product contains more than 0.1% total silica content, regardless of its particle size (i.e. respirable or not), it is classified as a carcinogen and therefore requires a carcinogenic warning label, whereas in the UK & Europe the hazard warning pictogram will apply only to a product that contains between 1 – 10% Respirable Crystalline Silica. At this level it is classed as a STOT-RE 2 Hazard.

STOT stands for Specific Target Organ Toxicity which in this case is the respiratory system.

Hazard Label:
Signal Word:DANGER
Hazard Class:H350: May cause cancer if inhaled. Causes
damage to the lungs, the immune system and
the kidneys through prolonged or repeated
exposure if inhaled.
Precautionary:P201: Obtain special instructions before use.
Other Hazards:None.


The classification of silica in regards to being a carcinogen
is different in different parts of the world. Silica is the major
constituent in traditional investment powder in the forms of silica
flour (ground silica) and Cristobalite (ground calcined silica), it
is also present as an unavoidable trace element in many other
minerals at very low levels.

In the UK & Europe silica is only classified as a carcinogen if it is produced as a result of a work activity.

In contrast in the United States of America if a product contains
more than 0.1% total silica content, regardless of its particle size
(i.e. respirable or not), it is classified as a carcinogen.

As an example, proposition 65 in The State of California USA
requires a cancer warning label on bags of sand containing
crystalline silica. This is the sand sold by large retailers and
routinely used for children’s play sand, landscaping, sports and recreational purposes. Whereas in the UK & Europe this warning label is not required.

Due to the possible trace elements of silica within the raw materials
used to make X-SIL we classify the product as having less than
1% total silica content,  whereas compared to traditional investment powders these will typically contain approximately 70-80% total silica content. 

Advantages of X-SIL

X-Sil has been developed to be able to cast all non-precious and precious alloys including High Palladium White Gold

It’s ease of use is one of it’s main advantages. GRS has engineered the product to at least match all cast surface finishes from our premium investment powder range without the need for any process or equipment changes.

Additionally, we understand the health of our customers workers is of paramount importance. By utilising X-Sil investment powder technology you are minimising your workforces potential exposure to respirable crystalline silica. 

About Goodwin Refractory Services

Goodwin Refractory Services Ltd (GRS) and its sister companies are the global market leader in the manufacture of Investment Casting Powder for the jewellery industry in the world, producing over 65,000 tonnes worldwide per year. 

GRS is continually investing in R&D and understands the requirement of close customer relationships combined with a world class technical support network. Their complex manufacturing process is backed up by exhaustive raw material control testing and in-house quality control.

Product Information Booklet