Isocyanate TDI Allergy Test
Isocyanate TDI Allergy Test can be requested without a referral, and this overview covers what to expect. The Isocyanate TDI Allergy Test is a blood test that checks for an immune response to toluene diisocyanate (TDI), a chemical used in polyurethane foams, coatings, and adhesives. It is ordered when a person has workplace or hobby exposure to TDI and symptoms such as wheezing, nasal congestion, or skin reactions. The test helps a clinician evaluate whether symptoms may be related to TDI sensitivity.
- Sample type
- blood
- Category
- Allergy
- Turnaround
- 1-3 business days
- Price
- $49
- Referral
- Not required
The Isocyanate TDI Allergy Test is a blood test that checks for an immune response to toluene diisocyanate (TDI), a chemical used in polyurethane foams, coatings, and adhesives. It is ordered when a person has workplace or hobby exposure to TDI and symptoms such as wheezing, nasal congestion, or skin reactions. The test helps a clinician evaluate whether symptoms may be related to TDI sensitivity.
What it measures
- TDI-specific IgE — An antibody that, if present, suggests the immune system has reacted to TDI.
- Total IgE — A general measure of allergic antibody levels; helps interpret the specific result.
- TDI-specific IgG — An antibody that may indicate past or ongoing exposure rather than allergy.
- Exposure history — Information about tasks, duration, and protective equipment used at work or home.
Who it is for
It is usually ordered by an allergist, occupational medicine physician, or primary care clinician for people who work with isocyanates or have symptoms after exposure.
Preparation
No fasting is required. Tell the clinician about all medicines, especially antihistamines, because some can affect allergy test results.
Results and what they mean
Results are reported as positive, negative, or a numeric level for each marker. A positive result does not by itself diagnose an allergy or asthma; a clinician interprets it with your symptoms and exposure history. This is general information, not medical advice.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the isocyanate tdi allergy test is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Do I need to stop my allergy medicine before this test?
Ask the clinician ordering the test. Some antihistamines can interfere with allergy testing, but the decision depends on your medicines and health history.
How soon will I get results?
Typical turnaround is 1 to 3 business days after the blood sample reaches the lab.
Can this test tell me if I have asthma?
No. It only checks for immune sensitivity to TDI. Asthma and other breathing conditions are diagnosed by a clinician using symptoms, exams, and breathing tests.
Is a positive result permanent?
Sensitivity can persist, but results should be interpreted with your exposure and symptoms. Discuss what a positive result means for your situation with a clinician.