Fume Hoods for Water Testing Processes

waterWater testing facilities and laboratories utilize a variety of analytical reagents to determine and monitor the presence of possibly hazardous, substances in water samples. In this post, we’ve reviewed the Safety Data Sheets (SDS) of these reagents indicate to see what type of respiratory safety measures should be taken by employees who are exposed to these compounds.

Water testing facilities run a series of tests (each with its own reagents) to determine if any number of potential contaminants are present in the water.

Some of these reagents and their corresponding tests produce fumes that are more hazardous and/or troublesome than others.

One test in particular that clients have requested respiratory solutions for is the boiler phosphate test which requires Amino Acid Reagant for Phosphate and Silica, Molybdate Reagent, and Sulfuric Acid.

Amino Acid Reagent for Phosphate & Silica

According to the SDS, Amino Acid Reagent for Phosphate and Silica is composed of:

  • 65% – 75% demineralized water (no health effects anticipated).
  • 20% – 30% N,N-Dimethylformamide (listed as toxic, may be embryotoxic, experimental carcinogen, causes severe eye irritation).
  • 5% – 10% Sodium Metabisulfite (may cause irritation and allergic reaction).
  • 1% – 5% Sodium Sulfite (may cause irritation and allergic reaction).


Overall hazard identification explains that this solution is “harmful if inhaled or absorbed through skin, causes eye irritation, may cause skin and respiratory tract irritation, may cause kidney or liver damage based on animal data.” Additionally, it produces an offensive and pungent amine odor.

Inhalation Protection

Not all analytical reagent SDSs specifically recommend fume hoods as an engineering control for inhalation protection; however, the health hazards associated with the ingredients in this solution prompt the recommendation for a laboratory fume hood when handling Amino Acid Reagent for Phosphate and Silica.

Molybdate Reagent

The following ingredients compose Molybdate Reagent:

  • 65% – 75% Demineralized Water (not hazardous).
  • 40% – 50% Sulfuric Acid (hazardous – GHS* classifications: skin corr. 1A, met corr. 1).
  • 1% – 10% Ammonium Molybdate (hazardous – GHS* classifications: acute tox. 4, eye irrit. 2, skin irrit. 2).
  • 0.1% – 1% Other Componenets (not hazardous).

*GHS stands for The Globally Harmonized System of Classification and Labelling of Chemicals. Learn more about this classification system on OSHA’s website.

Hazards & Exposure Controls

In regard to respiratory safety, a fume hood is not specifically recommended under “inhalation protection”, as is the case with the amino acid reagent; however, adequate ventilation is still suggested.

Sulfuric Acid Standard Solution

The SDS for Sulfuric Acid Standard Solution says the compound is composed of the following ingredients:

  • 50% – 60% Demineralized Water (no hazards anticipated).
  • 40% – 50% Sulfuric Acid (causes severe burns, harmful if inhaled, recognized carcinogen).

Hazards & Engineering Controls

Inhalation of this solution can cause respiratory tract irritation, difficulty breathing, teeth erosion, mouth soreness, and chronic exposure (or severe short-term overexposure) can lead to inflammation or damage of the lungs. Adequate ventilation is recommended for inhalation protection.

To sum up

Without protective technologies, technicians running this water quality test process could experience a range of potential health problems: severe eye irritation, reproductive issues, allergic reactions, organ damage, burns, cancer, and lung damage.

Respiratory Engineering Controls for this process

The most popular Sentry Air product for this Phosphate testing process is the Ductless Laboratory Fume Hood. These systems are available in a variety of standard width sizes: 12″, 18″, 24″, 30″, 40″, 50″, 60″, and 70″.

Customized hoods are also available to suit specific needs. Common customizations include cutouts (for sinks, microscopes, other equipment), specific material (metal, PVC, transparent materials), size alterations, air volume increase, dual-entry hoods, and a variety of additional amendments that allow for smoother operation.
40″ Wide Laboratory Fume Hood
Filter Media

For this particular test, the recommended filtration system is a specialty-blended Acid Gas and Activated Carbon filter. The acid gas filter would remove/neutralize vapors coming from the sulfite compounds and sulfuric acid, while the activated carbon filter adsorbs  the vapors from the N,N–Dimethylformamide.

Since most water testing labs also work with reagents in powder form and respirable powders are generated during testing, it is also recommended that a HEPA filter [up to 99.97% efficient on particles 0.3 microns and larger] be added to any filtration system used in water testing.

If additional reagents or chemicals are being utilized in conjunction with this, a Sentry Air Systems Applications Specialist will evaluate the process to ensure that this combination of filtration media remains adequate for your operation.

These recirculating systems do not require any costly external ducting and can be easily incorporated into existing laboratories.

This 40″ Ductless Laboratory Fume Hood is capable of up to

350 CFM and 100 FPM at the inlet of the hood

A similar configuration that adheres to the same basic fundamentals as Sentry Air’s standard Ductless Fume Hoods [recirculating air pattern and the same selection of filtration media]  may be more suitable for certain water testing applications. The Model 300 Winged Sentry is pictured below:

 The Model 300 Winged Sentry has a 13″ access area when the hinged, acrylic lid is in use. Custom cutouts, shown above, can be requested for tall equipment.

Contact us

If your water testing process requires a fume hood or similar air purification solution, a Sentry Air Systems Applications Specialist can discuss your options based on the chemicals you utilize and the space available to you within your facility.

You can call us at 1.800.799.4609, email us at sales@sentryair.com, or fill out the contact form below to receive additional information from an Applications Specialist.