casquery 0.2.1

Search Chemical Abstracts Service Registry Numbers (CASRNs) from the EPA Substance Registry Services (SRS) database.

casquery

Query the EPA Substance Registry Service (SRS) using CAS Registry Numbers (CASRN).

casquery provides:

• A command-line tool for searching CASRN records
• Normalization of messy CAS numbers
• CAS resolution (superseded → current CASRN)
• Batch processing of CSVs
• Multiple output formats (table, JSON, XML, CSV)

It works both as:

• A standalone script (python casquery.py)
• A PyPI-installable CLI (casquery …)

Installation

pip install casquery

Standalone Script Usage

You can also run it directly as a script without installing:

python casquery.py --help

Command Line Usage

# Help
casquery --help
casquery search --help

# Search EPA SRS
casquery search 375-73-5 29420-43-3

# Search with synonyms
casquery search --synonyms 375-73-5

# Output formats
casquery search 375-73-5 --format json
casquery search 375-73-5 --format xml
casquery search 375-73-5 --format csv

# Normalize CAS numbers
casquery normalize 1234567
# → 1234-56-7

# Resolve superseded CAS numbers
casquery resolve 29420-43-3

# Batch-process a CSV (Input CSV must contain a column of CASRN values.)
casquery batch input.csv --column analyte_cas --output cleaned.csv

Examples

Search for two CAS numbers

casquery search 7440-66-6 7440097

╭───────────────────────────────────────────────╮
│        EPA SRS CASRN Search Results           │
╰───────────────────────────────────────────────╯
cas_rn     systematicName     epaName     currentCasNumber
---------  ------------------  ----------  -----------------
7440-66-6  Zinc                Zinc        7440-66-6
7440-09-7  Potassium           Potassium   7440-09-7

Output JSON instead of a table

casquery search --format json 375-73-5

[
  {
    "cas_rn": "375-73-5",
    "systematicName": "Perfluorobutane sulfonic acid",
    "epaName": "PFBS",
    "currentCasNumber": "375-73-5"
  }
]