Trivalent chromates really hexavalent chromates. Medical search. Frequent questions

But if you have been using clear chromates all this time, your salt spray requirements are minimal and your platers could well have been using clear trivalent chrome conversion coatings all along. (finishing.com)
These developments have allowed applicators to eliminate the use of toxic hexavalent-chromate conversion coatings, thereby safeguarding the health of all involved in the handling and processing of zinc-plated parts. (constantcontact.com)
Chromate conversion coatings (also known as passivate coatings) are a chemical immersion process and are applied to electroplated zinc deposits to give protection against oxidation of the plated deposit. (finishing.com)
Environmentally friendly trivalent chromium is now a proven, economical alternative to hexavalent chromium coatings, offering high corrosion resistance for CWM Al, Mg and Zn die castings in a range of applications. (cwmdiecast.com)
These methods are applicable to - colourless and coloured chromate conversion coatings containing trivalent and hexavalent chromium in varying proportions and produced by either chemical or electrochemical processes, and - chromate coatings that are free from any supplementary coatings, such as oil, water or solventbased polymers or wax. (iteh.ai)
Aluminum chromate conversion coatings, often referred to as chemical film or under the trade names Alodine or Irridite, produce a thin coating in the range of 0.00001-0.00004 inches in thickness. (u2canmakemoney.ws)
Capable of applying hexavalent chromate and RoHS compliant trivalent (hexavalent chromium free) conversion coatings.Can work with brass, steel and copper parts as large as 11 ft. (cncmachiningptj.com)
What is the difference between Chromate and Chromium coatings? (seniorsserenity.be)
Our development of chromate conversion coatings for plated coatings helped seed developments in the field of aluminum treatments. (macdermidenthone.com)
Based on that deficiency, MacDermid Enthone developed the Iridite range of chromium-free coatings that has shown to be both safe and effective as a true replacement for the hexavalent chromium systems. (macdermidenthone.com)
At the center of the innovation, efforts are companies like MacDermid Enthone, whose development of chromate conversion coatings for plated coatings helped seed developments in the field of aluminum treatments. (macdermidenthone.com)
Hexavalent chromium is used in textile dyes, wood preservation, anti-corrosion products, chromate conversion coatings, and a variety of niche uses. (partcommunity.com)

Determining Dissolved Hexavalent Chromium in Water and Wastewater by Electrothermal Atomization. (epa.gov)
A procedure is described for separating dissolved hexavalent chromium (Cr(+6)) from trivalent chromium (Cr(+3)) and the water sample matrix by coprecipitation of lead chromate with lead sulfate in acetic acid solution. (epa.gov)

Iridite NCP is the safe, reliable and cost-effective alternative to chromate based pre-treatments for aluminum and has been developed in response to the ELV, RoHS and WEEE directives. (macdermidenthone.com)
Type II uses trivalent chromium (RoHS and REACH compliant) and produces a clear finish. (ctiroc.com)

The process that people put the chromate solution on the metal's surface to produce the trivalent and hexavalent chromium layer is called passivation or chromizing. (camelppgi.com)
Users, such as DeKalb Metal Finishing, combine this alkaline process with a system called trivalent passivation. (dekalbmetal.com)
Improvements in techniques and overall qualities have helped creating an increased acceptance of trivalent passivation. (dekalbmetal.com)
We have has accepted and now employ the more environmentally sensitive substitute that is trivalent chromate passivation, which is popular in zinc alloy plating for the automotive industry. (dekalbmetal.com)
HyPro 200 is a secondary passivation for use over all of Pavco's trivalent passivates. (agasem.com)

Brockovich unearthed evidence that cases of cancer and other illnesses in the town could be linked to the presence of hexavalent chromium in groundwater. (chemistryworld.com)

Type I uses hexavalent chromium and ranges in color from light to dark yellow, dependent on the immersion time. (ctiroc.com)

HyProTec™ LD is a high performance, cobalt-free trivalent passivate for zinc electrodeposits. (agasem.com)
HyPro™ Tec 291 is an economical, cobalt-free trivalent passivate for zinc electrodeposits. (agasem.com)
HyPro™ Black 3000 is a trivalent black passivate for zinc that provides 120 hours to white corrosion when sealed with an approved HyPro™ Sealer. (agasem.com)
HyPro™ Tec is a high performance, trivalent passivate for zinc and zinc-nickel electrodeposits. (agasem.com)
HyPro 200 will extend the corrosion protection of a trivalent passivate up to 100 hours to white salts. (agasem.com)
HyPro™ Black is a trivalent black passivate conversion coating for zinc that provides 120 hours to white corrosion when used in conjunction with HyPro™ 200 or HyPro™ Coat 330. (agasem.com)
And they found that answer in Columbia Chemical's COLDIP Midnight 1500 black trivalent passivate. (columbiachemical.com)
Midwest is pleased to be able to provide a deep dark, black passivate to its customers that doesn't come with any of the hexavalent issues like worker exposure, air emissions or expensive wastewater issues. (columbiachemical.com)

Some examples of workers at risk of being exposed to hexavalent chromium include the following: Welders working with carbon and stainless steel welding. (seniorsserenity.be)
Workers in many occupations are exposed to hexavalent chromium. (partcommunity.com)
Workers who are exposed to hexavalent chromium are at increased risk of developing lung cancer, asthma, or damage to the nasal epithelia and skin. (partcommunity.com)

The investigation was prompted by a request from an authorized representative of employees to evaluate the potential hazard associated with employee exposure to chromate pigments. (cdc.gov)
Lung cancer mortality among workers making lead chromate and zinc chromate pigments at three English factories. (cdc.gov)
A document published by the Occupational Safety and Health Administration in the United States notes that since the year 2000, there has been a decline in the use of hexavalent chromium compounds as pigments for paints and other materials. (chemistryworld.com)

The company, she alleged, had contaminated drinking water with wastewater containing hexavalent chromium at Hinkley, a town in southern California. (chemistryworld.com)
Hexavalent chromium is difficult to remove during conventional biological wastewater treatment. (iwaponline.com)
Hexavalent chromium is of particular concern because of its aquatic toxicity, and an increasing number of wastewater works have effluent discharge limits to protect receiving water courses, some as low as 8 μg Cr L −1 . (iwaponline.com)

Additional hexavalent chromium compounds are chromium trioxide and various salts of chromate and dichromate, among others. (partcommunity.com)
Chromium in this electrolyte is in hexavalent form and its salts are called Chromates. (microncoatings.it)

As long as you don't use the new "topcoats" that have been designed to help trivalent chromates approach the corrosion resistance of traditional yellow hexavalent chromates, I don't see any change. (finishing.com)
Our supplier now offers a Trivalent Chromium chromate that surpasses the Hexavalent in salt spray testing - this means you will receive zinc plating with better corrosion protection at no extra cost. (britishclassiccarparts.com)
The coating exhibits bare, unpainted, corrosion resistance that is equal to hexavalent chromates on many aluminium alloys. (macdermidenthone.com)
Hexavalent chromium (Cr VI) has been shown to be the predominant form of chromium released following in vivo and in vitro corrosion of these metal implants (Merritt and Brown, 1995 K. Merritt and S.A. Brown, J. Biomed. (strath.ac.uk)
HyPro™ Blue is designed to meet the corrosion protection requirements of all automotive specifications requiring the elimination of hexavalent chromium from passivates. (agasem.com)
Thanks to Columbia, Midwest Plating's customers are "extremely satisfied with the color and corrosion protection of Midnight 1500 and they are more than happy to have made the transition away from hexavalent black. (columbiachemical.com)

While harm resulting from ingesting lead-contaminated food is relatively well researched , the effects of eating food contaminated with chromium(VI), as a constituent of lead chromate, are not well understood. (cdc.gov)
The entire site is heavily contaminated with chromium, both trivalent and hexavalent. (pureearth.org)

Certain employees who had experienced nosebleeds and other hexavalent chromium related problems in the past had not experienced such problems for at least 1.5 to 2 years of work, probably as a result of the installation of local exhaust ventilation to prevent exposure. (cdc.gov)
1984). "Urinary excretion of chromium as an indicator of exposure to trivalent chromium sulphate in leather tanning. (cdc.gov)
1985). "An analysis of lung cancer risk from exposure to hexavalent chromium. (cdc.gov)
Problematic exposure is known to occur among workers who handle chromate-containing products and those who grind and/ or weld stainless steel. (partcommunity.com)
New OSHA regulations are forcing everyone to take a close look at their processes and implement changes to them or install engineering controls to help reduce hexavalent chromium exposure. (donaldson.com)
The Occupational Safety & Health Administration (OSHA) has defined two levels of exposure for hexavalent chromium: a Permissible Exposure Limit (PEL) and an Action Level (AL). (donaldson.com)
Midwest was using a proprietary silver-black chromate that had been working well for years, but Wortman reported many customers wanted to make the move away from the hex black product amid increasing industry regulations and growing concerns about worker exposure. (columbiachemical.com)

And also because it is metal, it doesn't matter to the end user whether it was deposited from a trivalent or hexavalent bath because, as deposited, it is neither of the two, it is simply chrome metal. (finishing.com)
When in production, the factory's main products were sodium acid chromate, chromic anhydride, chrome oxide green and other chromium products to be used in ceramic production, printing, electroplating, leather production and medicines. (pureearth.org)
The chemical name of chrome yellow is lead(II) chromate. (chemistryworld.com)
Useful search terms for hexavalent chromium include 'chromate' and 'chrome six. (donaldson.com)
Reading through articles and publications, you will see hexavalent chromium identified in different ways, including: Hex Chrome, Chromium (VI), Cr(VI), and Cr 6+. (donaldson.com)
To date, there are no alternatives to hexavalent chromium for hard chrome plating. (microncoatings.it)

M.J. McGuire, N.K. Blute, C. Seidel, G. Qin, L. Fong, Pilot-scale studies of hexavalent chromium removal from drinking water, J. Am. Water Works Assoc., 98 (2006) 34-143. (deswater.com)

Iridite NCP does not contain Lead, Cadmium, Chromium(hexavalent or trivalent), Mercury or PBB / PBDE compounds. (macdermidenthone.com)

Due to environmental pressures to eliminate all sources of hexavalent chromium from our products, we are looking to specify Trivalent plating processes for future projects. (finishing.com)
What industrial processes produce hexavalent chromium? (donaldson.com)
and 3) Hexavalent Chromium , typically from industrial processes like welding and thermal spray. (donaldson.com)
There are a variety of industrial processes that can produce hexavalent chromium. (donaldson.com)
This is because the hexavalent form is dissolved and is only sparingly removed by adsorption onto biomass in conventional processes. (iwaponline.com)
Chromium (Cr) is an abundant and useful transition metal, considered a micronutrient in its trivalent form and employed in a multitude of industrial processes in its other oxidation states (especially the hexavalent), due to its hardness and resistance to tarnishing. (iwaponline.com)

With a bright, cosmetically pleasing finish, this alternative combined conversion-functional coating meets stricter commercial and U.S. and European Union environmental mandates, avoiding the concerns with prohibited products using toxic hexavalent chromates. (cwmdiecast.com)
Hexavalent Chromium is the most toxic form of chromium. (donaldson.com)
The toxic heavy metal compound can be formed mainly as calcium chromate (CaCrO4) when chromium components in the alloy of the insulated surface, such as chromium (III) compounds encounter calcium oxide (CaO) under thermal conditions, usually in a temperature window between 300°C and 600°C. (kavarmat.com)

Faced with new regulations restricting emissions of hexavalent chromium from various plating operations, along with increasing requests from a customer base for products that are environmentally preferable, our plating supplier has decided to switch from Hexavalent Chromate to Trivalent Chromate. (britishclassiccarparts.com)
It is more environmentally friendly than hexavalent systems. (dekalbmetal.com)

What is the best way to increase the bath life and quality of trivalent passivates on zinc plate? (constantcontact.com)
One of the more significant developments of the last 20 years in the metal finishing industry is the commercial development and application of trivalent passivates on zinc electroplate. (constantcontact.com)
Further, these trivalent passivates have a substantially positive impact on the environment. (constantcontact.com)
Trivalent passivates are typically acidic in nature and operate at a pH between 1.6 and 2.2, under most operating situations. (constantcontact.com)

Hi, I'm a student from Mexico, and got a work to do about cleaning methods for metallic and organic contaminants on trivalent chromate conversion baths. (finishing.com)
It is important to realize hexavalent chromium has its own recommended threshold limit value (TLV) as established by the American Conference of Industrial Hygienists (ACGIH), and that this value may be lower than other components present as airborne contaminants. (donaldson.com)

We currently use a zinc plate with clear chromate conversion process. (finishing.com)
I am looking for information that describes the electrical properties of zinc plating with "chromate conversion" utilizing trivalent chromium in contrast to hexavalent chromium. (finishing.com)
In so far as chromate conversion coating. (finishing.com)
In a Chromate conversion coating, the part to be coated is the substrate (cathode) and the anode is the deposition active species from the conducting bath which are attracted to deposit on the substrate's crystal lattices, growing and spreading on the substrate surfaces, atomic layer by layer. (finishing.com)
To prevent confusion and keeping it simple, let's therefore conclude that chromate conversion coating is a type of immersion plating process or deposition. (finishing.com)
A conversion coating consisting of trivalent and hexavalent chromium compounds. (wakefieldthermal.com)
Chemical Conversion Coating is often referred to as chem film, chromate coating, or yellow chromate coating. (u2canmakemoney.ws)
Chromate Conversion chemically converts the surface properties of the metal (typically aluminum or magnesium) as opposed to plating which applies a coating onto the surface. (u2canmakemoney.ws)
Chemfilm is also known as chromate conversion coating, alodine and iridite coating. (u2canmakemoney.ws)

Based on environmental samplings, evaluation of ventilation systems, observations of employee work practices, and available toxicity information it is concluded that employee exposures to noncarcinogenic hexavalent chromium contained in sodium-bichromate (10588019), as measured during the survey, did not constitute a health hazard. (cdc.gov)
Sodium dichromate, an orange red compound, is an example of a hexavalent chromium compound. (chemistryworld.com)
Sodium dichromate is produced from the ore by first removing the iron and then oxidizing the trivalent chromium to form sodium dichromate. (chemistryworld.com)
Sodium dichromate, like many other sodium compounds, is highly soluble in water, and arguably the most important of all hexavalent chromium compounds. (chemistryworld.com)
It is a hexavalent chromium compound prepared from sodium dichromate by reactions with potassium chloride and then lead nitrate. (chemistryworld.com)
The use of sodium dichromate and other hexavalent chromium compounds is now facing a major problem. (chemistryworld.com)
Virtually all chromium ore is processed via hexavalent chromium, specifically the salt sodium dichromate. (partcommunity.com)

Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) refers to chemical compounds that contain the element chromium in the +6 oxidation state (thus hexavalent). (partcommunity.com)
The trivalent form, Cr(III), is the most stable oxidation state of chromium and compounds/complexes containing Cr(III) are common in natural systems ( Vaiopoulou & Gikas 2012 ). (iwaponline.com)

Hexavalent Chromium is a known human carcinogen and has been on the list of chemicals to be banned. (britishclassiccarparts.com)
Inhaled hexavalent chromium is recognized as a human carcinogen. (partcommunity.com)

D.L. Sedlak, P.G. Chan, Reduction of hexavalent chromium by ferrous iron, Geochim. (deswater.com)
M.A. Schlautman, I. Han, Effects of pH and dissolved oxygen on the reduction of hexavalent chromium by dissolved ferrous iron in poorly buffered aqueous systems, Water Res. (deswater.com)
Ferrous reduces hexavalent chromium to insoluble trivalent chromium, which can be readily settled out of waste streams as a particulate. (iwaponline.com)

Due to the high toxicity of Chromium in its hexavalent form (Cr VI) severe limitations are currently placed on its use. (microncoatings.it)

2003). At physiological pH, Cr (VI) exists predominantly as the chromate anion and as such can enter cells via non-specific anion channels. (strath.ac.uk)

Hexavalent chromium compounds are well known human carcinogens. (chemistryworld.com)
Other hexavalent chromium compounds have later sunset dates. (chemistryworld.com)
Even so, some experts believe that, for many applications, it will be difficult to replace hexavalent chromium compounds with equally effective but safer compounds. (chemistryworld.com)

Hexavalent chromium has become a hot topic in the thermal spray community and among welders. (donaldson.com)

Therefore, the search of new adsorbents for the removal of hexavalent chromium has directed attention to synthesize new materials with high adsorption efficiency and good regeneration ability. (hindawi.com)

A common method for removing chromium from aqueous solutions involves the reduction of hexavalent chromium to trivalent chromium . (brainmass.com)
The anionic Cr (VI) diffuses readily through the red blood cell (RBC) membrane and is bound by the haemoglobin probably after its rapid reduction to the cationic trivalent state within the RBC (Gray and Sterling, 1950). (strath.ac.uk)

I suppose that if chrom-"ate" is read as CrO3 then 'trivalent chromate' would actually be an oxymoron. (finishing.com)
This means the chromium has to be at a valance of +6 (hexavalent), but still we talk constantly of trivalent (+3) chromate, which seems to be an oxymoron. (seniorsserenity.be)

Metallic chromium in the feedstock may be converted to hexavalent form. (donaldson.com)
Hexavalent chromium may be present in a feedstock containing any form of chromium. (donaldson.com)
While chromium is considered to play a helpful role in the carbohydride metabolism in its trivalent form, the hexavalent species is classified as genotoxic and carcinogenic. (speciation.net)

Groundwater is also heavily contaminated likely both from past discharges and continuing releases as rainwater picks up contamination, particularly hexavalent chromium, from the site soil. (pureearth.org)
Eliminate any risk of chromium (especially hexavalent chromium) contamination to the XiangJiang River. (pureearth.org)
The contamination of hexavalent chromium species is a major problem in many industrial areas, such as electroplating and metal finishing industries [ 5 - 7 ]. (hindawi.com)

Metallic chromium, on the other hand, even when deposited from hexavalent chromium baths, has no limitations on its use since it is inert, and its dissolution in aggressive environments is also not problematic since it transforms from zerovalent chromium (Cr°) to nontoxic Cr trivalent (Cr III). (microncoatings.it)

Some platers also use the slang 'chromate' to mean a clear finish and 'dichromate' (Cr2O7) to mean a yellow finish, but that isn't actually correct either. (seniorsserenity.be)

D. Mohan, C.U. Pittman, Activated carbons and low cost adsorbents for remediation of tri- and hexavalent chromium from water, J. Hazard. (deswater.com)

In these situations the chromium is not originally hexavalent, but the high temperatures involved in the process result in oxidation that converts the chromium to a hexavalent state. (partcommunity.com)

Within the European Union, the use of hexavalent chromium in electronic equipment is largely prohibited by the Restriction of Hazardous Substances Directive. (partcommunity.com)
Due to the hazardous nature of hexavalent chromium, the REACh regulation restricted its use to companies that have obtained authorisation. (microncoatings.it)

Lead chromate, which contains chromium(VI), has been used to adulterate turmeric and other spices. (cdc.gov)

On more and more construction sites, power plants and combined heat and power plants, traces of the carcinogenic and mutagenic element calcium chromate (CaCrO4) are found both on the stripped equipment, such as engines and gas or steam turbines, and on the inside of the insulation elements after the insulation mattresses (also known as insulation blankets, insulation mats, etc.) have been removed. (kavarmat.com)

Because hexavalent chromium is usually only a percentage of the dust fume and mist generated from a process, it may be worth investigating the percent contribution of Cr(VI) verse other materials in the airstream. (donaldson.com)

Srivastava [ 12 ] discovered that sawdust is effective for removal of hexavalent chromium and other heavy metals. (hindawi.com)

I believe that the surface resistance of clear chromates is lower than yellow chromates. (finishing.com)

HyPro™ Tri Yellow is a two-component, single dip trivalent yellow chromate. (agasem.com)

Anatomy6

Organisms13

Diseases5

Chemicals and Drugs50

Analytical, Diagnostic and Therapeutic Techniques and Equipment14

Phenomena and Processes27

Disciplines and Occupations1

Anthropology, Education, Sociology and Social Phenomena1

Technology, Industry, Agriculture2

Information Science3

Health Care7

Coatings12

Dissolved hexavalent chromium2

RoHS2

Passivation5

Presence of hexavalent chromium1

Uses hexavalent chromium1

Passivate8

Exposed to hexavalent chromium3

Pigments3

Wastewater3

Salts2

Corrosion6

Contaminated with chromium2

Exposure7

Chrome6

Chromium removal1

Cadmium1

Processes6

Toxic3

Environmentally2

Passivates4

Contaminants2

Conversion9

Sodium7

Oxidation state2

Human carcinogen2

Ferrous3

Toxicity1

Predominantly1

Compounds3

Welders1

Adsorption1

Reduction2

Oxymoron2

Form3

Contamination3

Metallic1

Platers1

Adsorbents1

Converts1

Hazardous2

Lead1

Carcinogenic1

Process1

Removal1

Resistance1

YELLOW1